# ListControl

Namespace: **Wisej.Web**

Assembly: **Wisej.Framework** (3.0.0.0)

* [Control](/api/v3.0/wisej.web/general/control.md)
  * [ListControl](/api/v3.0/wisej.web/lists-and-grids/listcontrol.md)

Provides a common implementation of members for the [ListBox](/api/v3.0/wisej.web/lists-and-grids/listbox.md) and [ComboBox](/api/v3.0/wisej.web/lists-and-grids/combobox.md) classes.

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

```csharp
public class ListControl : Control
```

{% endtab %}

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

```visual-basic
Public Class ListControl
    Inherits Control
```

{% endtab %}
{% endtabs %}

## Properties

### ![](/files/uCY6T77rh488FWHzpJ6P)AllowHtml

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

### ![](/files/uCY6T77rh488FWHzpJ6P)BorderStyle

[BorderStyle](/api/v3.0/wisej.web/enumerations/wisej.web.borderstyle.md): Returns or sets the type of border that is drawn around the [ListControl](/api/v3.0/wisej.web/lists-and-grids/listcontrol.md).

### ![](/files/uCY6T77rh488FWHzpJ6P)DataSource

[Object](https://docs.microsoft.com/en-us/dotnet/api/system.object): Returns or sets the data source for this [ListControl](/api/v3.0/wisej.web/lists-and-grids/listcontrol.md).

**Throws:**

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

### ![](/files/uCY6T77rh488FWHzpJ6P)DisplayMember

[String](https://docs.microsoft.com/en-us/dotnet/api/system.string): Returns or sets the property to display for this [ListControl](/api/v3.0/wisej.web/lists-and-grids/listcontrol.md).

### ![](/files/uCY6T77rh488FWHzpJ6P)FormatInfo

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

### ![](/files/uCY6T77rh488FWHzpJ6P)FormatString

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

### ![](/files/uCY6T77rh488FWHzpJ6P)FormattingEnabled

[Boolean](https://docs.microsoft.com/en-us/dotnet/api/system.boolean): Returns or sets whether formatting is applied to the [DisplayMember](#displaymember) property of the [ListControl](/api/v3.0/wisej.web/lists-and-grids/listcontrol.md).

### ![](/files/uCY6T77rh488FWHzpJ6P)IconMember

[String](https://docs.microsoft.com/en-us/dotnet/api/system.string): Returns or sets the property to use as the icon for the items in the [ListControl](/api/v3.0/wisej.web/lists-and-grids/listcontrol.md).

### ![](/files/uCY6T77rh488FWHzpJ6P)Invalid

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

### ![](/files/uCY6T77rh488FWHzpJ6P)InvalidMessage

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

### ![](/files/uCY6T77rh488FWHzpJ6P)Modified

[Boolean](https://docs.microsoft.com/en-us/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/uCY6T77rh488FWHzpJ6P)PrefetchItems

[Int32](https://docs.microsoft.com/en-us/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).

### ![](/files/uCY6T77rh488FWHzpJ6P)SelectedIndex

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

### ![](/files/uCY6T77rh488FWHzpJ6P)SelectedValue

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

**Throws:**

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

### ![](/files/uCY6T77rh488FWHzpJ6P)ShowToolTips

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

### ![](/files/uCY6T77rh488FWHzpJ6P)ToolTipMember

[String](https://docs.microsoft.com/en-us/dotnet/api/system.string): Returns or sets the property to use as the tooltip for the items in the [ListControl](/api/v3.0/wisej.web/lists-and-grids/listcontrol.md), when the property [ShowToolTips](#showtooltips) is set to true.

### ![](/files/uCY6T77rh488FWHzpJ6P)ValueMember

[String](https://docs.microsoft.com/en-us/dotnet/api/system.string): Returns or sets the property to use as the actual value for the items in the [ListControl](/api/v3.0/wisej.web/lists-and-grids/listcontrol.md).

**Throws:**

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

### ![](/files/uCY6T77rh488FWHzpJ6P)VirtualScroll

[Boolean](https://docs.microsoft.com/en-us/dotnet/api/system.boolean): Enables or disables virtual scrolling for the [ListControl](/api/v3.0/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/v3.0/wisej.web/lists-and-grids/listcontrol.md) to host virtually unlimited items without any performance loss.

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.

## Methods

### ![](/files/uCY6T77rh488FWHzpJ6P)Append(data)

Populates the [ListControl](/api/v3.0/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/en-us/dotnet/api/system.object) | The object that contains data for the [ListControl](/api/v3.0/wisej.web/lists-and-grids/listcontrol.md) to display. |

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

Use this method to fill a [ListControl](/api/v3.0/wisej.web/lists-and-grids/listcontrol.md) without binding it to the data source.

### ![](/files/uCY6T77rh488FWHzpJ6P)Fill(data)

Populates the [ListControl](/api/v3.0/wisej.web/lists-and-grids/listcontrol.md) from the *data* .

| Parameter | Type                                                                | Description                                                                                                         |
| --------- | ------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------- |
| **data**  | [Object](https://docs.microsoft.com/en-us/dotnet/api/system.object) | The object that contains data for the [ListControl](/api/v3.0/wisej.web/lists-and-grids/listcontrol.md) to display. |

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

Use this method to fill a [ListControl](/api/v3.0/wisej.web/lists-and-grids/listcontrol.md) without binding it to the data source.

### ![](/files/uCY6T77rh488FWHzpJ6P)GetItemIcon(item)

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

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

**Returns:** [Object](https://docs.microsoft.com/en-us/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/uCY6T77rh488FWHzpJ6P)GetItemText(item)

Returns the text representation of the specified item.

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

**Returns:** [String](https://docs.microsoft.com/en-us/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/uCY6T77rh488FWHzpJ6P)GetItemToolTip(item)

Returns the tooltip text related to the object.

| Parameter | Type                                                                | Description                                                                 |
| --------- | ------------------------------------------------------------------- | --------------------------------------------------------------------------- |
| **item**  | [Object](https://docs.microsoft.com/en-us/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/en-us/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.

## Events

### ![](/files/uCY6T77rh488FWHzpJ6P)DataSourceChanged

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

### ![](/files/uCY6T77rh488FWHzpJ6P)DisplayMemberChanged

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

### ![](/files/uCY6T77rh488FWHzpJ6P)Format

[ListControlConvertEventHandler](/api/v3.0/wisej.web/lists-and-grids/listcontrol/wisej.web.listcontrolconverteventhandler.md) Fired when the control is bound to a data value.

### ![](/files/uCY6T77rh488FWHzpJ6P)FormatInfoChanged

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

### ![](/files/uCY6T77rh488FWHzpJ6P)FormatStringChanged

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

### ![](/files/uCY6T77rh488FWHzpJ6P)FormattingEnabledChanged

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

### ![](/files/uCY6T77rh488FWHzpJ6P)IconMemberChanged

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

### ![](/files/uCY6T77rh488FWHzpJ6P)ModifiedChanged

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

### ![](/files/uCY6T77rh488FWHzpJ6P)SelectedValueChanged

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

### ![](/files/uCY6T77rh488FWHzpJ6P)ToolTipMemberChanged

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

### ![](/files/uCY6T77rh488FWHzpJ6P)ValueMemberChanged

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

## Inherited By

| Name                                                                                                                                   | Description                                                                                                                                                                                                                  |
| -------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [CheckedListBox](/api/v3.0/wisej.web/lists-and-grids/checkedlistbox.md)                                                                | Displays a [ListBox](/api/v3.0/wisej.web/lists-and-grids/listbox.md) in which a check box is displayed to the left of each item.                                                                                             |
| [ComboBox](/api/v3.0/wisej.web/lists-and-grids/combobox.md)                                                                            | Represents a combo box control.                                                                                                                                                                                              |
| [ListBox](/api/v3.0/wisej.web/lists-and-grids/listbox.md)                                                                              | Represents a control to display a list of items.                                                                                                                                                                             |
| [DataGridViewComboBoxEditingControl](/api/v3.0/wisej.web/lists-and-grids/datagridview/wisej.web.datagridviewcomboboxeditingcontrol.md) | Represents a [ComboBox](/api/v3.0/wisej.web/lists-and-grids/combobox.md) control that can be hosted in a [DataGridViewComboBoxCell](/api/v3.0/wisej.web/lists-and-grids/datagridview/wisej.web.datagridviewcomboboxcell.md). |
| [ListViewComboBox](/api/v3.0/wisej.web/lists-and-grids/wisej.web.listviewcombobox.md)                                                  | The TreeViewComboBox control represents a [UserComboBox](/api/v3.0/wisej.web/lists-and-grids/wisej.web.usercombobox.md) control with a [ListView](/api/v3.0/wisej.web/lists-and-grids/listview.md) as the drop down panel.   |
| [TreeViewComboBox](/api/v3.0/wisej.web/lists-and-grids/wisej.web.treeviewcombobox.md)                                                  | The TreeViewComboBox control represents a [UserComboBox](/api/v3.0/wisej.web/lists-and-grids/wisej.web.usercombobox.md) control with a [TreeView](/api/v3.0/wisej.web/lists-and-grids/treeview.md) as the drop down panel.   |
| [UserComboBox](/api/v3.0/wisej.web/lists-and-grids/wisej.web.usercombobox.md)                                                          | The UserComboBox control represents a [ComboBox](/api/v3.0/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                                                                                                                |
| -------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------- |
| [IBindableComponent](/api/v3.0/wisej.web/data-binding/wisej.web.ibindablecomponent.md) | Bindable components implement this interface.                                                                              |
| [IWisejComponent](/api/v3.0/wisej.core/interfaces/wisej.core.iwisejcomponent.md)       | All wisej components implement this interface.                                                                             |
| [IWisejControl](/api/v3.0/wisej.core/interfaces/wisej.core.iwisejcontrol.md)           | All wisej controls derived from the [Control](/api/v3.0/wisej.web/general/control.md) class must implement this interface. |
| [IWisejSerializable](/api/v3.0/wisej.core/interfaces/wisej.core.iwisejserializable.md) | Allows an object to serialize itself.                                                                                      |


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