# ComboBox

Namespace: **Wisej.Web**

Assembly: **Wisej.Framework** (4.0.0.0)

* [Control](/api/wisej.web/general/control.md)
  * [ListControl](/api/wisej.web/lists-and-grids/listcontrol.md)
    * [ComboBox](/api/wisej.web/lists-and-grids/combobox.md)

Represents a combo box control.

{% tabs %}
{% tab title="C#" %}

```csharp
public class ComboBox : ListControl, ILabel, IReadOnly
```

{% endtab %}

{% tab title="VB.NET" %}

```visual-basic
Public Class ComboBox
    Inherits ListControl
    Implements ILabel, IReadOnly
```

{% endtab %}
{% endtabs %}

## Constructors

### ![](/files/hsR4ok3152WyAf8J2C1u) ComboBox()

Initializes an instance of ComboBox.

### ![](/files/hsR4ok3152WyAf8J2C1u) ComboBox(onSelectedIndexChanged)

Initializes a new instance of [ComboBox](/api/wisej.web/lists-and-grids/combobox.md) class with specific initial settings.

| Name                       | Type                                                                                | Description                                            |
| -------------------------- | ----------------------------------------------------------------------------------- | ------------------------------------------------------ |
| **onSelectedIndexChanged** | [Action\<Object, EventArgs>](https://docs.microsoft.com/dotnet/api/system.action-2) | [SelectedIndexChanged](#selectedindexchanged) handler. |

### ![](/files/hsR4ok3152WyAf8J2C1u) ComboBox(label, onSelectedIndexChanged)

Initializes a new instance of [ComboBox](/api/wisej.web/lists-and-grids/combobox.md) class with specific initial settings.

| Name                       | Type                                                                                | Description                                                                                      |
| -------------------------- | ----------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------ |
| **label**                  | [String](https://docs.microsoft.com/dotnet/api/system.string)                       | The initial text to display in the [TextBox](/api/wisej.web/editors/wisej.web.textbox.md) label. |
| **onSelectedIndexChanged** | [Action\<Object, EventArgs>](https://docs.microsoft.com/dotnet/api/system.action-2) | [SelectedIndexChanged](#selectedindexchanged) handler.                                           |

### ![](/files/hsR4ok3152WyAf8J2C1u) ComboBox(dataSource, displayMember, valueMember, iconMember, onSelectedIndexChanged)

Initializes a new instance of [ComboBox](/api/wisej.web/lists-and-grids/combobox.md) class with specific initial settings.

| Name                       | Type                                                                                | Description                                                                           |
| -------------------------- | ----------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------- |
| **dataSource**             | [Object](https://docs.microsoft.com/dotnet/api/system.object)                       | Initial [DataSource](/api/wisej.web/lists-and-grids/listcontrol.md#datasource).       |
| **displayMember**          | [String](https://docs.microsoft.com/dotnet/api/system.string)                       | Initial [DisplayMember](/api/wisej.web/lists-and-grids/listcontrol.md#displaymember). |
| **valueMember**            | [String](https://docs.microsoft.com/dotnet/api/system.string)                       | Initial [ValueMember](/api/wisej.web/lists-and-grids/listcontrol.md#valuemember).     |
| **iconMember**             | [String](https://docs.microsoft.com/dotnet/api/system.string)                       | Initial [IconMember](/api/wisej.web/lists-and-grids/listcontrol.md#iconmember).       |
| **onSelectedIndexChanged** | [Action\<Object, EventArgs>](https://docs.microsoft.com/dotnet/api/system.action-2) | Optional [SelectedIndexChanged](#selectedindexchanged) handler.                       |

### ![](/files/hsR4ok3152WyAf8J2C1u) ComboBox(location, size, onSelectedIndexChanged)

Initializes an instance of [ComboBox](/api/wisej.web/lists-and-grids/combobox.md) with the given datasource, size, location, and action.

| Name                       | Type                                                                                | Description                                                     |
| -------------------------- | ----------------------------------------------------------------------------------- | --------------------------------------------------------------- |
| **location**               | [Point](https://docs.microsoft.com/dotnet/api/system.drawing.point)                 | Initial location.                                               |
| **size**                   | [Size](https://docs.microsoft.com/dotnet/api/system.drawing.size)                   | Initial size.                                                   |
| **onSelectedIndexChanged** | [Action\<Object, EventArgs>](https://docs.microsoft.com/dotnet/api/system.action-2) | Optional [SelectedIndexChanged](#selectedindexchanged) handler. |

### ![](/files/hsR4ok3152WyAf8J2C1u) ComboBox(location, size, dataSource, displayMember, valueMember, iconMember, onSelectedIndexChanged)

Initializes an instance of [ComboBox](/api/wisej.web/lists-and-grids/combobox.md) with the given datasource, size, location, and action.

| Name                       | Type                                                                                | Description                                                                           |
| -------------------------- | ----------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------- |
| **location**               | [Point](https://docs.microsoft.com/dotnet/api/system.drawing.point)                 | Initial location.                                                                     |
| **size**                   | [Size](https://docs.microsoft.com/dotnet/api/system.drawing.size)                   | Initial size.                                                                         |
| **dataSource**             | [Object](https://docs.microsoft.com/dotnet/api/system.object)                       | Initial [DataSource](/api/wisej.web/lists-and-grids/listcontrol.md#datasource).       |
| **displayMember**          | [String](https://docs.microsoft.com/dotnet/api/system.string)                       | Initial [DisplayMember](/api/wisej.web/lists-and-grids/listcontrol.md#displaymember). |
| **valueMember**            | [String](https://docs.microsoft.com/dotnet/api/system.string)                       | Initial [ValueMember](/api/wisej.web/lists-and-grids/listcontrol.md#valuemember).     |
| **iconMember**             | [String](https://docs.microsoft.com/dotnet/api/system.string)                       | Initial [IconMember](/api/wisej.web/lists-and-grids/listcontrol.md#iconmember).       |
| **onSelectedIndexChanged** | [Action\<Object, EventArgs>](https://docs.microsoft.com/dotnet/api/system.action-2) | Optional [SelectedIndexChanged](#selectedindexchanged) handler.                       |

### ![](/files/hsR4ok3152WyAf8J2C1u) ComboBox(label, location, size, onSelectedIndexChanged)

Initializes an instance of [ComboBox](/api/wisej.web/lists-and-grids/combobox.md) with the given datasource, size, location, and action.

| Name                       | Type                                                                                | Description                                                                                      |
| -------------------------- | ----------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------ |
| **label**                  | [String](https://docs.microsoft.com/dotnet/api/system.string)                       | The initial text to display in the [TextBox](/api/wisej.web/editors/wisej.web.textbox.md) label. |
| **location**               | [Point](https://docs.microsoft.com/dotnet/api/system.drawing.point)                 | Initial location.                                                                                |
| **size**                   | [Size](https://docs.microsoft.com/dotnet/api/system.drawing.size)                   | Initial size.                                                                                    |
| **onSelectedIndexChanged** | [Action\<Object, EventArgs>](https://docs.microsoft.com/dotnet/api/system.action-2) | Optional [SelectedIndexChanged](#selectedindexchanged) handler.                                  |

### ![](/files/hsR4ok3152WyAf8J2C1u) ComboBox(label, location, size, dataSource, displayMember, valueMember, iconMember, onSelectedIndexChanged)

Initializes an instance of [ComboBox](/api/wisej.web/lists-and-grids/combobox.md) with the given datasource, size, location, and action.

| Name                       | Type                                                                                | Description                                                                                      |
| -------------------------- | ----------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------ |
| **label**                  | [String](https://docs.microsoft.com/dotnet/api/system.string)                       | The initial text to display in the [TextBox](/api/wisej.web/editors/wisej.web.textbox.md) label. |
| **location**               | [Point](https://docs.microsoft.com/dotnet/api/system.drawing.point)                 | Initial location.                                                                                |
| **size**                   | [Size](https://docs.microsoft.com/dotnet/api/system.drawing.size)                   | Initial size.                                                                                    |
| **dataSource**             | [Object](https://docs.microsoft.com/dotnet/api/system.object)                       | Initial [DataSource](/api/wisej.web/lists-and-grids/listcontrol.md#datasource).                  |
| **displayMember**          | [String](https://docs.microsoft.com/dotnet/api/system.string)                       | Initial [DisplayMember](/api/wisej.web/lists-and-grids/listcontrol.md#displaymember).            |
| **valueMember**            | [String](https://docs.microsoft.com/dotnet/api/system.string)                       | Initial [ValueMember](/api/wisej.web/lists-and-grids/listcontrol.md#valuemember).                |
| **iconMember**             | [String](https://docs.microsoft.com/dotnet/api/system.string)                       | Initial [IconMember](/api/wisej.web/lists-and-grids/listcontrol.md#iconmember).                  |
| **onSelectedIndexChanged** | [Action\<Object, EventArgs>](https://docs.microsoft.com/dotnet/api/system.action-2) | Optional [SelectedIndexChanged](#selectedindexchanged) handler.                                  |

## Properties

### ![](/files/hsR4ok3152WyAf8J2C1u) AllowHtml

[Boolean](https://docs.microsoft.com/dotnet/api/system.boolean): Returns or sets a value indicating that the control can display html in the Text property. (Default: `False`)

### ![](/files/hsR4ok3152WyAf8J2C1u) AutoCompleteMode

[AutoCompleteMode](/api/wisej.web/enumerations/wisej.web.autocompletemode.md): Returns or sets how automatic completion works for the [ComboBox](/api/wisej.web/lists-and-grids/combobox.md). (Default: `None`)

### ![](/files/hsR4ok3152WyAf8J2C1u) AutoSize

[Boolean](https://docs.microsoft.com/dotnet/api/system.boolean): Returns or sets whether the height of the control is set automatically. (Default: `True`)

### ![](/files/hsR4ok3152WyAf8J2C1u) CharacterCasing

[CharacterCasing](/api/wisej.web/editors/wisej.web.charactercasing.md): Returns or sets whether the [ComboBox](/api/wisej.web/lists-and-grids/combobox.md) control modifies the case of characters as they are typed. (Default: `Normal`)

### ![](/files/lzopMboA31bVq8UIcbT3) DefaultSize

[Size](https://docs.microsoft.com/dotnet/api/system.drawing.size): Returns the default size for the ComboBox control.

### ![](/files/hsR4ok3152WyAf8J2C1u) DropDownHeight

[Int32](https://docs.microsoft.com/dotnet/api/system.int32): Returns or sets the maximum height in pixels of the drop-down portion of the [ComboBox](/api/wisej.web/lists-and-grids/combobox.md). (Default: `400`)

**Throws:**

* [ArgumentException](https://docs.microsoft.com/dotnet/api/system.argumentexception) The specified value is less than one.

### ![](/files/hsR4ok3152WyAf8J2C1u) DropDownStyle

[ComboBoxStyle](/api/wisej.web/enumerations/wisej.web.comboboxstyle.md): Returns or sets the drop down style of the combo box. (Default: `DropDown`)

### ![](/files/hsR4ok3152WyAf8J2C1u) DropDownWidth

[Int32](https://docs.microsoft.com/dotnet/api/system.int32): Returns or sets the maximum width in pixels of the drop-down list of the [ComboBox](/api/wisej.web/lists-and-grids/combobox.md). When the value is 0, the drop-down list will grow to fit the largest item. (Default: `0`)

**Throws:**

* [ArgumentException](https://docs.microsoft.com/dotnet/api/system.argumentexception) The specified value is less than one.

### ![](/files/hsR4ok3152WyAf8J2C1u) DroppedDown

[Boolean](https://docs.microsoft.com/dotnet/api/system.boolean): Returns or sets whether the combo box is displaying its drop-down portion.

### ![](/files/hsR4ok3152WyAf8J2C1u) EnableNativeContextMenu

[Boolean](https://docs.microsoft.com/dotnet/api/system.boolean): Enables or disables the browser's context menu. (Default: `True`)

### ![](/files/hsR4ok3152WyAf8J2C1u) IncrementalSelection

[Boolean](https://docs.microsoft.com/dotnet/api/system.boolean): Returns or sets whether items are selected incrementally as the user types within a timeout of 1 second. (Default: `True`)

### ![](/files/hsR4ok3152WyAf8J2C1u) ItemHeight

[Int32](https://docs.microsoft.com/dotnet/api/system.int32): Gets or sets the height of the list items in the drop-down list. When the value is -1, uses the value set in the theme. (Default: `-1`)

**Throws:**

* [ArgumentOutOfRangeException](https://docs.microsoft.com/dotnet/api/system.argumentoutofrangeexception) The assigned value is less than -1; or the assigned value is greater than 500.

### ![](/files/hsR4ok3152WyAf8J2C1u) Items

[ObjectCollection](/api/wisej.web/lists-and-grids/combobox/wisej.web.combobox.objectcollection.md): Returns the collection of the items contained in this [ComboBox](/api/wisej.web/lists-and-grids/combobox.md).

### ![](/files/hsR4ok3152WyAf8J2C1u) Label

[LabelWrapper](/api/wisej.web/editors/wisej.web.labelwrapper.md): Provides a label related to the control.

### ![](/files/hsR4ok3152WyAf8J2C1u) LabelText

[String](https://docs.microsoft.com/dotnet/api/system.string): Returns or sets the localizable label associated with this control. (Default: `""`)

### ![](/files/hsR4ok3152WyAf8J2C1u) LazyLoading

[Boolean](https://docs.microsoft.com/dotnet/api/system.boolean): Returns or sets whether the items are sent to the client the first time the list is opened and enables the [Load](#load) event. (Default: `False`)

### ![](/files/hsR4ok3152WyAf8J2C1u) MaxLength

[Int32](https://docs.microsoft.com/dotnet/api/system.int32): Returns or sets the number of characters a user can type into the [ComboBox](/api/wisej.web/lists-and-grids/combobox.md). (Default: `0`)

**Throws:**

* [ArgumentOutOfRangeException](https://docs.microsoft.com/dotnet/api/system.argumentoutofrangeexception) The value is less than 0.

### ![](/files/hsR4ok3152WyAf8J2C1u) ReadOnly

[Boolean](https://docs.microsoft.com/dotnet/api/system.boolean): Returns or sets whether the control is read-only. (Default: `False`)

### ![](/files/hsR4ok3152WyAf8J2C1u) SelectedIndex

[Int32](https://docs.microsoft.com/dotnet/api/system.int32): Returns or sets the index of the currently selected item.

**Throws:**

* [ArgumentOutOfRangeException](https://docs.microsoft.com/dotnet/api/system.argumentoutofrangeexception) The specified index is less than -1; o the specified index is greater than the number of items in the combo box.

### ![](/files/hsR4ok3152WyAf8J2C1u) SelectedItem

[Object](https://docs.microsoft.com/dotnet/api/system.object): Returns or sets currently selected item in the [ComboBox](/api/wisej.web/lists-and-grids/combobox.md).

### ![](/files/hsR4ok3152WyAf8J2C1u) SelectedText

[String](https://docs.microsoft.com/dotnet/api/system.string): Returns or sets the text that is selected in the editable portion of a [ComboBox](/api/wisej.web/lists-and-grids/combobox.md).

### ![](/files/hsR4ok3152WyAf8J2C1u) SelectionLength

[Int32](https://docs.microsoft.com/dotnet/api/system.int32): Returns or sets the number of characters selected in the editable portion of the combo box.

**Throws:**

* [ArgumentException](https://docs.microsoft.com/dotnet/api/system.argumentexception) The value was less than zero.

### ![](/files/hsR4ok3152WyAf8J2C1u) SelectionStart

[Int32](https://docs.microsoft.com/dotnet/api/system.int32): Returns or sets the starting index of text selected in the combo box.

**Throws:**

* [ArgumentException](https://docs.microsoft.com/dotnet/api/system.argumentexception) The value is less than zero.

### ![](/files/hsR4ok3152WyAf8J2C1u) Sorted

[Boolean](https://docs.microsoft.com/dotnet/api/system.boolean): Returns or sets whether the items in the combo box are sorted. (Default: `False`)

**Throws:**

* [ArgumentException](https://docs.microsoft.com/dotnet/api/system.argumentexception) An attempt was made to sort a [ComboBox](/api/wisej.web/lists-and-grids/combobox.md) that is attached to a data source.

### ![](/files/hsR4ok3152WyAf8J2C1u) SpellCheck

[Boolean](https://docs.microsoft.com/dotnet/api/system.boolean): Returns or sets whether the text in the [ComboBox](/api/wisej.web/lists-and-grids/combobox.md) is spell checked by the browser. (Default: `False`)

### ![](/files/hsR4ok3152WyAf8J2C1u) Text

[String](https://docs.microsoft.com/dotnet/api/system.string): Returns or sets the text associated with this control. (Default: `""`)

### ![](/files/hsR4ok3152WyAf8J2C1u) Tools

[ComponentToolCollection](/api/wisej.web/editors/wisej.web.componenttoolcollection.md): Returns the instance of [ComponentToolCollection](/api/wisej.web/editors/wisej.web.componenttoolcollection.md) associated with this control.

### ![](/files/hsR4ok3152WyAf8J2C1u) Watermark

[String](https://docs.microsoft.com/dotnet/api/system.string): Returns or sets the text to show when the control is empty. (Default: `null`)

## Methods

### ![](/files/hsR4ok3152WyAf8J2C1u) BeginUpdate()

Not used. Kept for compatibility.

### ![](/files/hsR4ok3152WyAf8J2C1u) Copy()

Copies the current selection in the text box to the Clipboard.

### ![](/files/lzopMboA31bVq8UIcbT3) CreateItemCollection()

Creates a new instance of the item collection.

**Returns:** [ObjectCollection](/api/wisej.web/lists-and-grids/combobox/wisej.web.combobox.objectcollection.md). A [ObjectCollection](/api/wisej.web/lists-and-grids/combobox/wisej.web.combobox.objectcollection.md) that represents the new item collection.

### ![](/files/hsR4ok3152WyAf8J2C1u) Cut()

Moves the current selection in the text box to the Clipboard.

### ![](/files/lzopMboA31bVq8UIcbT3) Dispose(disposing)

Disposes the control.

| Parameter     | Type                                                            | Description                                                                 |
| ------------- | --------------------------------------------------------------- | --------------------------------------------------------------------------- |
| **disposing** | [Boolean](https://docs.microsoft.com/dotnet/api/system.boolean) | true when this method is called by the application rather than a finalizer. |

### ![](/files/hsR4ok3152WyAf8J2C1u) EndUpdate()

Not used. Kept for compatibility.

### ![](/files/hsR4ok3152WyAf8J2C1u) FindString(text)

Returns the index of the first item in the [ComboBox](/api/wisej.web/lists-and-grids/combobox.md) that starts with the specified string.

| Parameter | Type                                                          | Description                                                                      |
| --------- | ------------------------------------------------------------- | -------------------------------------------------------------------------------- |
| **text**  | [String](https://docs.microsoft.com/dotnet/api/system.string) | The [String](https://docs.microsoft.com/dotnet/api/system.string) to search for. |

**Returns:** [Int32](https://docs.microsoft.com/dotnet/api/system.int32). The zero-based index of the first item found; returns -1 if no match is found.

### ![](/files/hsR4ok3152WyAf8J2C1u) FindString(text, startIndex)

Returns the index of the first item in the [ComboBox](/api/wisej.web/lists-and-grids/combobox.md) beyond the specified index that starts with the specified string. The search is not case sensitive.

| Parameter      | Type                                                          | Description                                                                                                                   |
| -------------- | ------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------- |
| **text**       | [String](https://docs.microsoft.com/dotnet/api/system.string) | The [String](https://docs.microsoft.com/dotnet/api/system.string) to search for.                                              |
| **startIndex** | [Int32](https://docs.microsoft.com/dotnet/api/system.int32)   | The zero-based index of the item before the first item to be searched. Set to -1 to search from the beginning of the control. |

**Returns:** [Int32](https://docs.microsoft.com/dotnet/api/system.int32). The zero-based index of the first item found; returns -1 if no match is found, or 0 if the *text* parameter specifies [Empty](https://docs.microsoft.com/dotnet/api/system.string.empty).

### ![](/files/hsR4ok3152WyAf8J2C1u) FindStringExact(text)

Finds the first item in the combo box that matches the specified string.

| Parameter | Type                                                          | Description                                                                      |
| --------- | ------------------------------------------------------------- | -------------------------------------------------------------------------------- |
| **text**  | [String](https://docs.microsoft.com/dotnet/api/system.string) | The [String](https://docs.microsoft.com/dotnet/api/system.string) to search for. |

**Returns:** [Int32](https://docs.microsoft.com/dotnet/api/system.int32). The zero-based index of the first item found; returns -1 if no match is found, or 0 if the *text* parameter specifies [Empty](https://docs.microsoft.com/dotnet/api/system.string.empty).

### ![](/files/hsR4ok3152WyAf8J2C1u) FindStringExact(text, startIndex)

Finds the first item after the specified index that matches the specified string.

| Parameter      | Type                                                          | Description                                                                                                                   |
| -------------- | ------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------- |
| **text**       | [String](https://docs.microsoft.com/dotnet/api/system.string) | The [String](https://docs.microsoft.com/dotnet/api/system.string) to search for.                                              |
| **startIndex** | [Int32](https://docs.microsoft.com/dotnet/api/system.int32)   | The zero-based index of the item before the first item to be searched. Set to -1 to search from the beginning of the control. |

**Returns:** [Int32](https://docs.microsoft.com/dotnet/api/system.int32). The zero-based index of the first item found; returns -1 if no match is found, or 0 if the *text* parameter specifies [Empty](https://docs.microsoft.com/dotnet/api/system.string.empty).

### ![](/files/lzopMboA31bVq8UIcbT3) OnAutoComplete(e)

Fires the [AutoComplete](#autocomplete) event.

| Parameter | Type                                                                                             | Description                                                                                                                      |
| --------- | ------------------------------------------------------------------------------------------------ | -------------------------------------------------------------------------------------------------------------------------------- |
| **e**     | [HandledEventArgs](https://docs.microsoft.com/dotnet/api/system.componentmodel.handledeventargs) | A [HandledEventArgs](https://docs.microsoft.com/dotnet/api/system.componentmodel.handledeventargs) that contains the event data. |

### ![](/files/lzopMboA31bVq8UIcbT3) OnDataSourceChanged(e)

Fires the [DataSourceChanged](/api/wisej.web/lists-and-grids/listcontrol.md#datasourcechanged) event.

| Parameter | Type                                                                | Description                                                                                         |
| --------- | ------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------- |
| **e**     | [EventArgs](https://docs.microsoft.com/dotnet/api/system.eventargs) | A [EventArgs](https://docs.microsoft.com/dotnet/api/system.eventargs) that contains the event data. |

### ![](/files/lzopMboA31bVq8UIcbT3) OnDisplayMemberChanged(e)

Fires the [DisplayMemberChanged](/api/wisej.web/lists-and-grids/listcontrol.md#displaymemberchanged) event.

| Parameter | Type                                                                | Description                                                                                         |
| --------- | ------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------- |
| **e**     | [EventArgs](https://docs.microsoft.com/dotnet/api/system.eventargs) | A [EventArgs](https://docs.microsoft.com/dotnet/api/system.eventargs) that contains the event data. |

### ![](/files/lzopMboA31bVq8UIcbT3) OnDropDown(e)

Fires the [DropDown](#dropdown) event.

| Parameter | Type                                                                | Description                                                                                         |
| --------- | ------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------- |
| **e**     | [EventArgs](https://docs.microsoft.com/dotnet/api/system.eventargs) | A [EventArgs](https://docs.microsoft.com/dotnet/api/system.eventargs) that contains the event data. |

### ![](/files/lzopMboA31bVq8UIcbT3) OnDropDownClosed(e)

Fires the [DropDownClosed](#dropdownclosed) event.

| Parameter | Type                                                                | Description                                                                                         |
| --------- | ------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------- |
| **e**     | [EventArgs](https://docs.microsoft.com/dotnet/api/system.eventargs) | A [EventArgs](https://docs.microsoft.com/dotnet/api/system.eventargs) that contains the event data. |

### ![](/files/lzopMboA31bVq8UIcbT3) OnDropDownStyleChanged(e)

Fires the [DropDownStyleChanged](#dropdownstylechanged) event.

| Parameter | Type                                                                | Description                                                                                         |
| --------- | ------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------- |
| **e**     | [EventArgs](https://docs.microsoft.com/dotnet/api/system.eventargs) | A [EventArgs](https://docs.microsoft.com/dotnet/api/system.eventargs) that contains the event data. |

### ![](/files/lzopMboA31bVq8UIcbT3) OnLoad(e)

Fires the [Load](#load) event.

| Parameter | Type                                                                | Description                                                                                         |
| --------- | ------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------- |
| **e**     | [EventArgs](https://docs.microsoft.com/dotnet/api/system.eventargs) | A [EventArgs](https://docs.microsoft.com/dotnet/api/system.eventargs) that contains the event data. |

### ![](/files/lzopMboA31bVq8UIcbT3) OnReadOnlyChanged(e)

Fires the [ReadOnlyChanged](#readonlychanged) event.

| Parameter | Type                                                                | Description                                                                                          |
| --------- | ------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------- |
| **e**     | [EventArgs](https://docs.microsoft.com/dotnet/api/system.eventargs) | An [EventArgs](https://docs.microsoft.com/dotnet/api/system.eventargs) that contains the event data. |

### ![](/files/lzopMboA31bVq8UIcbT3) OnSelectedIndexChanged(e)

Fires the [SelectedIndexChanged](#selectedindexchanged) event.

| Parameter | Type                                                                | Description                                                                                         |
| --------- | ------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------- |
| **e**     | [EventArgs](https://docs.microsoft.com/dotnet/api/system.eventargs) | A [EventArgs](https://docs.microsoft.com/dotnet/api/system.eventargs) that contains the event data. |

### ![](/files/lzopMboA31bVq8UIcbT3) OnSelectedItemChanged(e)

Fires the [SelectedItemChanged](#selecteditemchanged) event.

| Parameter | Type                                                                | Description                                                                                         |
| --------- | ------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------- |
| **e**     | [EventArgs](https://docs.microsoft.com/dotnet/api/system.eventargs) | A [EventArgs](https://docs.microsoft.com/dotnet/api/system.eventargs) that contains the event data. |

### ![](/files/lzopMboA31bVq8UIcbT3) OnSelectionChangeCommitted(e)

Fires the [SelectionChangeCommitted](#selectionchangecommitted) event.

| Parameter | Type                                                                | Description                                                                                         |
| --------- | ------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------- |
| **e**     | [EventArgs](https://docs.microsoft.com/dotnet/api/system.eventargs) | A [EventArgs](https://docs.microsoft.com/dotnet/api/system.eventargs) that contains the event data. |

### ![](/files/lzopMboA31bVq8UIcbT3) OnSortedChanged(e)

Fires the [SortedChanged](#sortedchanged) event.

| Parameter | Type                                                                | Description                                                                                         |
| --------- | ------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------- |
| **e**     | [EventArgs](https://docs.microsoft.com/dotnet/api/system.eventargs) | A [EventArgs](https://docs.microsoft.com/dotnet/api/system.eventargs) that contains the event data. |

### ![](/files/lzopMboA31bVq8UIcbT3) OnToolClick(e)

Fires the ToolClick event.

| Parameter | Type                                                                         | Description                                                                                                  |
| --------- | ---------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------ |
| **e**     | [ToolClickEventArgs](/api/wisej.web/editors/wisej.web.toolclickeventargs.md) | A [ToolClickEventArgs](/api/wisej.web/editors/wisej.web.toolclickeventargs.md) that contains the event data. |

### ![](/files/lzopMboA31bVq8UIcbT3) OnValidating(e)

Fires the [Validating](/api/wisej.web/general/control.md#validating) event.

| Parameter | Type                                                                                           | Description                                                                                         |
| --------- | ---------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------- |
| **e**     | [CancelEventArgs](https://docs.microsoft.com/dotnet/api/system.componentmodel.canceleventargs) | A [EventArgs](https://docs.microsoft.com/dotnet/api/system.eventargs) that contains the event data. |

### ![](/files/lzopMboA31bVq8UIcbT3) OnValueMemberChanged(e)

Fires the [ValueMemberChanged](/api/wisej.web/lists-and-grids/listcontrol.md#valuememberchanged) event.

| Parameter | Type                                                                | Description                                                                                         |
| --------- | ------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------- |
| **e**     | [EventArgs](https://docs.microsoft.com/dotnet/api/system.eventargs) | A [EventArgs](https://docs.microsoft.com/dotnet/api/system.eventargs) that contains the event data. |

### ![](/files/lzopMboA31bVq8UIcbT3) OnWebEvent(e)

Processes the event from the client.

| Parameter | Type                                                        | Description      |
| --------- | ----------------------------------------------------------- | ---------------- |
| **e**     | [WisejEventArgs](/api/wisej.core/general/wisejeventargs.md) | Event arguments. |

### ![](/files/lzopMboA31bVq8UIcbT3) OnWebRender(config)

Renders the client component.

| Parameter  | Type                                                          | Description                   |
| ---------- | ------------------------------------------------------------- | ----------------------------- |
| **config** | [Object](https://docs.microsoft.com/dotnet/api/system.object) | Dynamic configuration object. |

### ![](/files/lzopMboA31bVq8UIcbT3) OnWebUpdate(state)

Updates the client component using the state information.

| Parameter | Type                                                          | Description           |
| --------- | ------------------------------------------------------------- | --------------------- |
| **state** | [Object](https://docs.microsoft.com/dotnet/api/system.object) | Dynamic state object. |

### ![](/files/hsR4ok3152WyAf8J2C1u) Paste()

Replaces the current selection in the text box with the contents of the Clipboard.

### ![](/files/lzopMboA31bVq8UIcbT3) RefreshItem(index)

Refreshes the item contained at the specified location.

| Parameter | Type                                                        | Description                          |
| --------- | ----------------------------------------------------------- | ------------------------------------ |
| **index** | [Int32](https://docs.microsoft.com/dotnet/api/system.int32) | The location of the item to refresh. |

### ![](/files/lzopMboA31bVq8UIcbT3) RefreshItems()

Reloads all the [ComboBox](/api/wisej.web/lists-and-grids/combobox.md) items from the data source.

### ![](/files/hsR4ok3152WyAf8J2C1u) Select(start, length)

Selects a range of text in the editable portion of the [ComboBox](/api/wisej.web/lists-and-grids/combobox.md).

| Parameter  | Type                                                        | Description                                                                            |
| ---------- | ----------------------------------------------------------- | -------------------------------------------------------------------------------------- |
| **start**  | [Int32](https://docs.microsoft.com/dotnet/api/system.int32) | The position of the first character in the current text selection within the text box. |
| **length** | [Int32](https://docs.microsoft.com/dotnet/api/system.int32) | The number of characters to select.                                                    |

### ![](/files/hsR4ok3152WyAf8J2C1u) SelectAll()

Selects all the text in the editable portion of the [ComboBox](/api/wisej.web/lists-and-grids/combobox.md).

### ![](/files/lzopMboA31bVq8UIcbT3) SetBoundsCore(x, y, width, height, specified)

Sets the specified bounds of the [ComboBox](/api/wisej.web/lists-and-grids/combobox.md) control.

| Parameter     | Type                                                                        | Description                                                                                              |
| ------------- | --------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------- |
| **x**         | [Int32](https://docs.microsoft.com/dotnet/api/system.int32)                 | The new [Left](/api/wisej.web/general/control.md#left) property value of the control.                    |
| **y**         | [Int32](https://docs.microsoft.com/dotnet/api/system.int32)                 | The new [Top](/api/wisej.web/general/control.md#top) property value of the control.                      |
| **width**     | [Int32](https://docs.microsoft.com/dotnet/api/system.int32)                 | The new [Width](/api/wisej.web/general/control.md#width) property value of the control.                  |
| **height**    | [Int32](https://docs.microsoft.com/dotnet/api/system.int32)                 | Not used.                                                                                                |
| **specified** | [BoundsSpecified](/api/wisej.web/enumerations/wisej.web.boundsspecified.md) | A combination of the [BoundsSpecified](/api/wisej.web/enumerations/wisej.web.boundsspecified.md) values. |

### ![](/files/lzopMboA31bVq8UIcbT3) SetItemCore(index, value)

Sets the object with the specified index in the derived class.

| Parameter | Type                                                          | Description                    |
| --------- | ------------------------------------------------------------- | ------------------------------ |
| **index** | [Int32](https://docs.microsoft.com/dotnet/api/system.int32)   | The array index of the object. |
| **value** | [Object](https://docs.microsoft.com/dotnet/api/system.object) | The object.                    |

### ![](/files/lzopMboA31bVq8UIcbT3) SetItemsCore(value)

Sets the specified array of objects in a collection in the derived class.

| Parameter | Type                                                                    | Description        |
| --------- | ----------------------------------------------------------------------- | ------------------ |
| **value** | [IList](https://docs.microsoft.com/dotnet/api/system.collections.ilist) | An array of items. |

### ![](/files/lzopMboA31bVq8UIcbT3) Sort()

Sorts the items in the [ComboBox](/api/wisej.web/lists-and-grids/combobox.md).

## Events

### ![](/files/hsR4ok3152WyAf8J2C1u) AutoComplete

[HandledEventHandler](https://docs.microsoft.com/dotnet/api/system.componentmodel.handledeventhandler) Fired before the [Validating](/api/wisej.web/general/control.md#validating) event when [DropDownStyle](#dropdownstyle) is set to [DropDown](/api/wisej.web/enumerations/wisej.web.comboboxstyle.md#fields) or [Simple](/api/wisej.web/enumerations/wisej.web.comboboxstyle.md#fields).

The application may implement a different way to select the item when the user types a text and the ComboBox is validated. Set e.Handled to true to override the standard behavior.

```csharp


this.comboBox1.AutoComplete += (s, e) =>
{
  if (this.comboBox1.Text == "T")
  {
    this.compoBox1.SelectedIndex = 1;
    e.Handled = true;
  }
}


```

### ![](/files/hsR4ok3152WyAf8J2C1u) DropDown

[EventHandler](https://docs.microsoft.com/dotnet/api/system.eventhandler) Fired when the drop-down portion of a [ComboBox](/api/wisej.web/lists-and-grids/combobox.md) is shown.

### ![](/files/hsR4ok3152WyAf8J2C1u) DropDownClosed

[EventHandler](https://docs.microsoft.com/dotnet/api/system.eventhandler) Fired when the drop-down portion of the [ComboBox](/api/wisej.web/lists-and-grids/combobox.md) is no longer visible.

### ![](/files/hsR4ok3152WyAf8J2C1u) DropDownStyleChanged

[EventHandler](https://docs.microsoft.com/dotnet/api/system.eventhandler) Fired when the [DropDownStyle](#dropdownstyle) property has changed.

### ![](/files/hsR4ok3152WyAf8J2C1u) Load

[EventHandler](https://docs.microsoft.com/dotnet/api/system.eventhandler) Fired when the drop-down list is first opened and the [LazyLoading](#lazyloading) property is true.

When [LazyLoading](#lazyloading) is true An application may fill the items at any time prior to the drop-down list being opened, or while processing the [DropDown](#dropdown) or [Load](#load) event.

### ![](/files/hsR4ok3152WyAf8J2C1u) ReadOnlyChanged

[EventHandler](https://docs.microsoft.com/dotnet/api/system.eventhandler) Fired when the value of the [ReadOnly](#readonly) property has changed.

### ![](/files/hsR4ok3152WyAf8J2C1u) SelectedIndexChanged

[EventHandler](https://docs.microsoft.com/dotnet/api/system.eventhandler) Fired when the [SelectedIndex](#selectedindex) property has changed.

### ![](/files/hsR4ok3152WyAf8J2C1u) SelectedItemChanged

[EventHandler](https://docs.microsoft.com/dotnet/api/system.eventhandler) Fired when the [SelectedItem](#selecteditem) property has changed.

### ![](/files/hsR4ok3152WyAf8J2C1u) SelectionChangeCommitted

[EventHandler](https://docs.microsoft.com/dotnet/api/system.eventhandler) Fired when the selected item has changed and that change is displayed in the [ComboBox](/api/wisej.web/lists-and-grids/combobox.md).

### ![](/files/hsR4ok3152WyAf8J2C1u) SortedChanged

[EventHandler](https://docs.microsoft.com/dotnet/api/system.eventhandler) Fired when the [Sorted](#sorted) property has changed.

### ![](/files/hsR4ok3152WyAf8J2C1u) ToolClick

[ToolClickEventHandler](/api/wisej.web/editors/wisej.web.toolclickeventhandler.md) Fired when a [ComponentTool](/api/wisej.web/editors/wisej.web.componenttool.md) is clicked.

## Inherited By

| Name                                                                                                                              | Description                                                                                                                                                                                                        |
| --------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| [DataGridViewComboBoxEditingControl](/api/wisej.web/lists-and-grids/datagridview/wisej.web.datagridviewcomboboxeditingcontrol.md) | Represents a [ComboBox](/api/wisej.web/lists-and-grids/combobox.md) control that can be hosted in a [DataGridViewComboBoxCell](/api/wisej.web/lists-and-grids/datagridview/wisej.web.datagridviewcomboboxcell.md). |
| [ListViewComboBox](/api/wisej.web/lists-and-grids/wisej.web.listviewcombobox.md)                                                  | The TreeViewComboBox control represents a [UserComboBox](/api/wisej.web/lists-and-grids/wisej.web.usercombobox.md) control with a [ListView](/api/wisej.web/lists-and-grids/listview.md) as the drop down panel.   |
| [TreeViewComboBox](/api/wisej.web/lists-and-grids/wisej.web.treeviewcombobox.md)                                                  | The TreeViewComboBox control represents a [UserComboBox](/api/wisej.web/lists-and-grids/wisej.web.usercombobox.md) control with a [TreeView](/api/wisej.web/lists-and-grids/treeview.md) as the drop down panel.   |
| [UserComboBox](/api/wisej.web/lists-and-grids/wisej.web.usercombobox.md)                                                          | The UserComboBox control represents a [ComboBox](/api/wisej.web/lists-and-grids/combobox.md) control with a custom panel that drops down when the user clicks the down arrow.                                      |

## Implements

| Name                                                                              | Description                                                                                                                                                                                                                                     |
| --------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [IUserData](/api/wisej.web/interfaces/wisej.web.iuserdata.md)                     | Provides access to the `UserData` and `Tag` properties associated to the component implementing this interface.                                                                                                                                 |
| [IBindableComponent](/api/wisej.web/data-binding/wisej.web.ibindablecomponent.md) | Bindable components implement this interface.                                                                                                                                                                                                   |
| [IDropTarget](/api/wisej.web/interfaces/wisej.web.idroptarget.md)                 | Controls that support drag & drop operations implement this interface.                                                                                                                                                                          |
| [ILabel](/api/wisej.web/interfaces/wisej.web.ilabel.md)                           | Provides access to the [LabelWrapper](/api/wisej.web/editors/wisej.web.labelwrapper.md) associated with the controls that implement this interface.                                                                                             |
| [IReadOnly](/api/wisej.web/interfaces/wisej.web.ireadonly.md)                     | Provides access to the [ReadOnly](/api/wisej.web/interfaces/wisej.web.ireadonly.md#readonly) property for coontrols that support the read-only mode.                                                                                            |
| [IModified](/api/wisej.web/interfaces/wisej.web.imodified.md)                     | Provides access to the [Modified](/api/wisej.web/interfaces/wisej.web.imodified.md#modified) property and [ModifiedChanged](/api/wisej.web/interfaces/wisej.web.imodified.md#modifiedchanged) event for controls that implement this interface. |
| [IValidation](/api/wisej.web/interfaces/wisej.web.ivalidation.md)                 | Provides access to the validation events and properties property for controls that support validation.                                                                                                                                          |
| [IWisejComponent](/api/wisej.core/interfaces/wisej.core.iwisejcomponent.md)       | All wisej components implement this interface.                                                                                                                                                                                                  |
| [IWisejControl](/api/wisej.core/interfaces/wisej.core.iwisejcontrol.md)           | All wisej controls derived from the [Control](/api/wisej.web/general/control.md) class must implement this interface.                                                                                                                           |
| [IWisejSerializable](/api/wisej.core/interfaces/wisej.core.iwisejserializable.md) | Allows an object to serialize itself.                                                                                                                                                                                                           |


---

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```
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