# ListControl

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)

Provides a common implementation of members for the [ListBox](/api/wisej.web/lists-and-grids/listbox.md) and [ComboBox](/api/wisej.web/lists-and-grids/combobox.md) classes.

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

```csharp
public class ListControl : Control, IValidation, IModified
```

{% endtab %}

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

```visual-basic
Public Class ListControl
    Inherits Control
    Implements IValidation, IModified
```

{% endtab %}
{% endtabs %}

## 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/lzopMboA31bVq8UIcbT3) AllowSelection

[Boolean](https://docs.microsoft.com/dotnet/api/system.boolean): Returns a value indicating whether the list enables selection of list items.

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

[BorderStyle](/api/wisej.web/enumerations/wisej.web.borderstyle.md): Returns or sets the type of border that is drawn around the [ListControl](/api/wisej.web/lists-and-grids/listcontrol.md). (Default: `Solid`)

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

[Object](https://docs.microsoft.com/dotnet/api/system.object): Returns or sets the data source for this [ListControl](/api/wisej.web/lists-and-grids/listcontrol.md). (Default: `null`)

**Throws:**

* [ArgumentException](https://docs.microsoft.com/dotnet/api/system.argumentexception)\
  The assigned value does not implement the [IList](https://docs.microsoft.com/dotnet/api/system.collections.ilist) or [IListSource](https://docs.microsoft.com/dotnet/api/system.componentmodel.ilistsource) interfaces.

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

[String](https://docs.microsoft.com/dotnet/api/system.string): Returns or sets the property to display for this [ListControl](/api/wisej.web/lists-and-grids/listcontrol.md). (Default: `""`)

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

[IFormatProvider](https://docs.microsoft.com/dotnet/api/system.iformatprovider): Returns or sets the [IFormatProvider](https://docs.microsoft.com/dotnet/api/system.iformatprovider) that provides custom formatting behavior. (Default: `null`)

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

[String](https://docs.microsoft.com/dotnet/api/system.string): Returns or sets the format-specifier characters that indicate how a value is to be displayed. (Default: `""`)

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

[Boolean](https://docs.microsoft.com/dotnet/api/system.boolean): Returns or sets whether formatting is applied to the [DisplayMember](#displaymember) property of the [ListControl](/api/wisej.web/lists-and-grids/listcontrol.md). (Default: `False`)

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

[String](https://docs.microsoft.com/dotnet/api/system.string): Returns or sets the property to use as the icon for the items in the [ListControl](/api/wisej.web/lists-and-grids/listcontrol.md). (Default: `""`)

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

[Boolean](https://docs.microsoft.com/dotnet/api/system.boolean): Returns or sets a value that indicates that the control is invalid.

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

[String](https://docs.microsoft.com/dotnet/api/system.string): Returns or sets the invalid message that is shown in the invalid tooltip. (Default: `""`)

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

[Boolean](https://docs.microsoft.com/dotnet/api/system.boolean): Returns or sets a value that indicates that the control has been modified by the user since the control was created or its contents were last set.

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

[Int32](https://docs.microsoft.com/dotnet/api/system.int32): Returns or sets the number of items to prefetch outside of the visible area when [VirtualScroll](#virtualscroll) is set to true. The default is 0 (disabled). (Default: `0`)

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

[Int32](https://docs.microsoft.com/dotnet/api/system.int32): When overridden in a derived class, gets or sets the zero-based index of the currently selected item.

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

[Object](https://docs.microsoft.com/dotnet/api/system.object): Returns or sets the value of the member property specified by the [ValueMember](#valuemember) property. (Default: `null`)

**Throws:**

* [InvalidOperationException](https://docs.microsoft.com/dotnet/api/system.invalidoperationexception)\
  The assigned value is null or the empty string ("").

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

[Boolean](https://docs.microsoft.com/dotnet/api/system.boolean): Returns or sets whether to show tooltips (set using [ToolTipMember](#tooltipmember)) for the list items. (Default: `False`)

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

[String](https://docs.microsoft.com/dotnet/api/system.string): Returns or sets the property to use as the tooltip for the items in the [ListControl](/api/wisej.web/lists-and-grids/listcontrol.md), when the property [ShowToolTips](#showtooltips) is set to true. (Default: `""`)

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

[String](https://docs.microsoft.com/dotnet/api/system.string): Returns or sets the property to use as the actual value for the items in the [ListControl](/api/wisej.web/lists-and-grids/listcontrol.md). (Default: `""`)

**Throws:**

* [ArgumentException](https://docs.microsoft.com/dotnet/api/system.argumentexception)\
  The specified property cannot be found on the object specified by the [DataSource](#datasource) property.

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

[Boolean](https://docs.microsoft.com/dotnet/api/system.boolean): Enables or disables virtual scrolling for the [ListControl](/api/wisej.web/lists-and-grids/listcontrol.md). When virtual scrolling is enabled, only the visible items are rendered in the browser allowing the [ListControl](/api/wisej.web/lists-and-grids/listcontrol.md) to host virtually unlimited items without any performance loss. (Default: `False`)

When [VirtualScroll](#virtualscroll) is set to true, all the items must be of the same height, limiting the more flexible HTML rendering available when [VirtualScroll](#virtualscroll) is off (default).\
Setting the property [PrefetchItems](#prefetchitems) to a value greater than 0 allows the virtual view to prefetch the specified number of items outside of the visible area to enable smoother scrolling.**Throws:**

* [InvalidOperationException](https://docs.microsoft.com/dotnet/api/system.invalidoperationexception)\
  Horizontal orientation is not supported with virtual scrolling.

## Methods

### ![](/files/hsR4ok3152WyAf8J2C1u) Append(data)

Populates the [ListControl](/api/wisej.web/lists-and-grids/listcontrol.md) from the *data* appending the items to the existing items.

| Parameter | Type                                                          | Description                                                                                                    |
| --------- | ------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------- |
| **data**  | [Object](https://docs.microsoft.com/dotnet/api/system.object) | The object that contains data for the [ListControl](/api/wisej.web/lists-and-grids/listcontrol.md) to display. |

**Returns:** [Int32](https://docs.microsoft.com/dotnet/api/system.int32). Numbers of items appended.

Use this method to fill a [ListControl](/api/wisej.web/lists-and-grids/listcontrol.md) without binding it to the data source.

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

Dispose 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) Fill(data)

Populates the [ListControl](/api/wisej.web/lists-and-grids/listcontrol.md) from the *data* .

| Parameter | Type                                                          | Description                                                                                                    |
| --------- | ------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------- |
| **data**  | [Object](https://docs.microsoft.com/dotnet/api/system.object) | The object that contains data for the [ListControl](/api/wisej.web/lists-and-grids/listcontrol.md) to display. |

**Returns:** [Int32](https://docs.microsoft.com/dotnet/api/system.int32). Numbers of items added.

Use this method to fill a [ListControl](/api/wisej.web/lists-and-grids/listcontrol.md) without binding it to the data source.

### ![](/files/lzopMboA31bVq8UIcbT3) FilterItemOnProperty(item)

Retrieves the current value of the [ListControl](/api/wisej.web/lists-and-grids/listcontrol.md) item, if it is a property of an object, given the item.

| Parameter | Type                                                          | Description                                                                                   |
| --------- | ------------------------------------------------------------- | --------------------------------------------------------------------------------------------- |
| **item**  | [Object](https://docs.microsoft.com/dotnet/api/system.object) | The object the [ListControl](/api/wisej.web/lists-and-grids/listcontrol.md) item is bound to. |

**Returns:** [Object](https://docs.microsoft.com/dotnet/api/system.object). The filtered object.

### ![](/files/lzopMboA31bVq8UIcbT3) FilterItemOnProperty(item, field)

Returns the current value of the [ListControl](/api/wisej.web/lists-and-grids/listcontrol.md) item, if it is a property of an object given the item and the property name.

| Parameter | Type                                                          | Description                                                                                                 |
| --------- | ------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------- |
| **item**  | [Object](https://docs.microsoft.com/dotnet/api/system.object) | The object the [ListControl](/api/wisej.web/lists-and-grids/listcontrol.md) item is bound to.               |
| **field** | [String](https://docs.microsoft.com/dotnet/api/system.string) | The property name of the item the [ListControl](/api/wisej.web/lists-and-grids/listcontrol.md) is bound to. |

**Returns:** [Object](https://docs.microsoft.com/dotnet/api/system.object). The filtered object.

### ![](/files/hsR4ok3152WyAf8J2C1u) GetItemIcon(item)

Returns the icon object, either an instance of [Image](https://docs.microsoft.com/dotnet/api/system.drawing.image) or a [String](https://docs.microsoft.com/dotnet/api/system.string) representing the icon name or URL, of the specified item.

| Parameter | Type                                                          | Description                                                         |
| --------- | ------------------------------------------------------------- | ------------------------------------------------------------------- |
| **item**  | [Object](https://docs.microsoft.com/dotnet/api/system.object) | The object from which to get the icon to display for the list item. |

**Returns:** [Object](https://docs.microsoft.com/dotnet/api/system.object). If the [IconMember](#iconmember) property is not specified, the value returned by [GetItemIcon](#getitemicon-item) is null. Otherwise, the method returns the object value of the member specified in the [IconMember](#iconmember) property for the object specified in the *item* parameter.

### ![](/files/hsR4ok3152WyAf8J2C1u) GetItemText(item)

Returns the text representation of the specified item.

| Parameter | Type                                                          | Description                                           |
| --------- | ------------------------------------------------------------- | ----------------------------------------------------- |
| **item**  | [Object](https://docs.microsoft.com/dotnet/api/system.object) | The object from which to get the contents to display. |

**Returns:** [String](https://docs.microsoft.com/dotnet/api/system.string). If the [DisplayMember](#displaymember) property is not specified, the value returned by [GetItemText](#getitemtext-item) is the value of the item's ToString method. Otherwise, the method returns the string value of the member specified in the [DisplayMember](#displaymember) property for the object specified in the *item* parameter.

### ![](/files/hsR4ok3152WyAf8J2C1u) GetItemToolTip(item)

Returns the tooltip text related to the object.

| Parameter | Type                                                          | Description                                                                 |
| --------- | ------------------------------------------------------------- | --------------------------------------------------------------------------- |
| **item**  | [Object](https://docs.microsoft.com/dotnet/api/system.object) | The object from which to get the tooltip text to display for the list item. |

**Returns:** [String](https://docs.microsoft.com/dotnet/api/system.string). If the [ToolTipMember](#tooltipmember) property is not specified, the value returned by [GetItemToolTip](#getitemtooltip-item) is null. Otherwise, the method returns the value of the member specified in the [ToolTipMember](#tooltipmember) property for the object specified in the *item* parameter.

### ![](/files/lzopMboA31bVq8UIcbT3) IsInputKey(keyData)

Handles special input keys, such as PAGE UP, PAGE DOWN, HOME, END, and so on.

| Parameter   | Type                                                  | Description                                                                 |
| ----------- | ----------------------------------------------------- | --------------------------------------------------------------------------- |
| **keyData** | [Keys](/api/wisej.web/enumerations/wisej.web.keys.md) | One of the values of [Keys](/api/wisej.web/enumerations/wisej.web.keys.md). |

**Returns:** [Boolean](https://docs.microsoft.com/dotnet/api/system.boolean). true if the *keyData* parameter specifies the [End](/api/wisej.web/enumerations/wisej.web.keys.md#fields), [Home](/api/wisej.web/enumerations/wisej.web.keys.md#fields), [PageUp](/api/wisej.web/enumerations/wisej.web.keys.md#fields), or [PageDown](/api/wisej.web/enumerations/wisej.web.keys.md#fields) key; false if the *keyData* parameter specifies [Alt](/api/wisej.web/enumerations/wisej.web.keys.md#fields).

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

Fires the [BindingContextChanged](/api/wisej.web/general/control.md#bindingcontextchanged) 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) OnDataSourceChanged(e)

Fires the [DataSourceChanged](#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](#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) OnFormat(e)

Raises the [Format](#format) event.

| Parameter | Type                                                                                                               | Description                                                                                                                                        |
| --------- | ------------------------------------------------------------------------------------------------------------------ | -------------------------------------------------------------------------------------------------------------------------------------------------- |
| **e**     | [ListControlConvertEventArgs](/api/wisej.web/lists-and-grids/listcontrol/wisej.web.listcontrolconverteventargs.md) | A [ListControlConvertEventArgs](/api/wisej.web/lists-and-grids/listcontrol/wisej.web.listcontrolconverteventargs.md) that contains the event data. |

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

Fires the [FormatInfoChanged](#formatinfochanged) 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) OnFormatStringChanged(e)

Fires the [FormatStringChanged](#formatstringchanged) 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) OnFormattingEnabledChanged(e)

Fires the [FormattingEnabledChanged](#formattingenabledchanged) 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) OnIconMemberChanged(e)

Fires the [IconMemberChanged](#iconmemberchanged) 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) OnModifiedChanged(e)

Fires the [ModifiedChanged](#modifiedchanged) 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) OnSelectedIndexChanged(e)

Fires the [SelectedValueChanged](#selectedvaluechanged) 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) OnSelectedValueChanged(e)

Fires the [SelectedValueChanged](#selectedvaluechanged) 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) OnToolTipMemberChanged(e)

Fires the [ToolTipMemberChanged](#tooltipmemberchanged) 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) 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 [CancelEventArgs](https://docs.microsoft.com/dotnet/api/system.componentmodel.canceleventargs) that contains the event data. |

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

Fires the [ValueMemberChanged](#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) OnWebRender(config)

Renders the client component.

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

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

When overridden in a derived class, resynchronizes the data of the object at the specified index with the contents of the data source.

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

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

When overridden in a derived class, resynchronizes the item data with the contents of the data source.

### ![](/files/lzopMboA31bVq8UIcbT3) RenderItem(item)

Renders the text representation of the specified item. If AllowHtml is set to false, the text is encoded.

| Parameter | Type                                                          | Description                                           |
| --------- | ------------------------------------------------------------- | ----------------------------------------------------- |
| **item**  | [Object](https://docs.microsoft.com/dotnet/api/system.object) | The object from which to get the contents to display. |

**Returns:** [Object](https://docs.microsoft.com/dotnet/api/system.object). If the [DisplayMember](#displaymember) property is not specified, the value returned by [GetItemText](#getitemtext-item) is the value of the item's ToString method. Otherwise, the method returns the string value of the member specified in the [DisplayMember](#displaymember) property for the object specified in the *item* parameter.

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

When overridden in a derived class, 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(items)

When overridden in a derived class, sets the specified array of objects in a collection in the derived class.

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

## Events

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

[EventHandler](https://docs.microsoft.com/dotnet/api/system.eventhandler) Fired when the [DataSource](#datasource) changes.

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

[EventHandler](https://docs.microsoft.com/dotnet/api/system.eventhandler) Fired when the [DisplayMember](#displaymember) property changes.

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

[ListControlConvertEventHandler](/api/wisej.web/lists-and-grids/listcontrol/wisej.web.listcontrolconverteventhandler.md) Fired when the control is bound to a data value.

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

[EventHandler](https://docs.microsoft.com/dotnet/api/system.eventhandler) Fired when the value of the [FormatInfo](#formatinfo) property changes.

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

[EventHandler](https://docs.microsoft.com/dotnet/api/system.eventhandler) Fired when value of the [FormatString](#formatstring) property changes.

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

[EventHandler](https://docs.microsoft.com/dotnet/api/system.eventhandler) Fired when the value of the [FormattingEnabled](#formattingenabled) property changes.

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

[EventHandler](https://docs.microsoft.com/dotnet/api/system.eventhandler) Fired when the [IconMember](#iconmember) property changes.

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

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

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

[EventHandler](https://docs.microsoft.com/dotnet/api/system.eventhandler) Fired when the [SelectedValue](#selectedvalue) property changes.

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

[EventHandler](https://docs.microsoft.com/dotnet/api/system.eventhandler) Fired when the [ToolTipMember](#tooltipmember) property changes.

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

[EventHandler](https://docs.microsoft.com/dotnet/api/system.eventhandler) Fired when the [ValueMember](#valuemember) property changes.

## Inherited By

| Name                                                                                                                              | Description                                                                                                                                                                                                        |
| --------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| [CheckedListBox](/api/wisej.web/lists-and-grids/checkedlistbox.md)                                                                | Displays a [ListBox](/api/wisej.web/lists-and-grids/listbox.md) in which a check box is displayed to the left of each item.                                                                                        |
| [ComboBox](/api/wisej.web/lists-and-grids/combobox.md)                                                                            | Represents a combo box control.                                                                                                                                                                                    |
| [ListBox](/api/wisej.web/lists-and-grids/listbox.md)                                                                              | Represents a control to display a list of items.                                                                                                                                                                   |
| [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.                                                                                                                                                                          |
| [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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