# ListBoxExtensions

Namespace: **Wisej.Web.Markup**

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

Adds [fluent markup](https://learn.microsoft.com/en-us/dotnet/communitytoolkit/maui/markup/markup) extension methods to the [ListBox](/api/wisej.web/lists-and-grids/listbox.md) class.

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

```csharp
public class ListBoxExtensions
```

{% endtab %}

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

```visual-basic
Public Class ListBoxExtensions
```

{% endtab %}
{% endtabs %}

## Methods

### ![](/files/lIX317sDtMTZJBi9oSIx) HorizontalScrollbar\<TListBox>(listBox, value)

Sets the HorizontalScrollbar property of the specified [ListBox](/api/wisej.web/lists-and-grids/listbox.md).

| Parameter    | Type                                                                               | Description                                                                                       |
| ------------ | ---------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------- |
| **TListBox** |                                                                                    | The type of the list box, must inherit from [ListBox](/api/wisej.web/lists-and-grids/listbox.md). |
| **listBox**  | [TListBox](/api/wisej.web.markup/extensions/wisej.web.markup.listboxextensions.md) | The list box for which to set the HorizontalScrollbar property.                                   |
| **value**    | [Boolean](https://docs.microsoft.com/dotnet/api/system.boolean)                    | A boolean indicating whether a horizontal scrollbar is shown.                                     |

**Returns:** [TListBox](/api/wisej.web.markup/extensions/wisej.web.markup.listboxextensions.md). The modified list box with the updated HorizontalScrollbar property.

This method allows you to specify whether a horizontal scrollbar should be shown for the list box.

```csharp

myListBox.HorizontalScrollbar(true);

```

### ![](/files/lIX317sDtMTZJBi9oSIx) IncrementalSelection\<TListBox>(listBox, value)

Sets the IncrementalSelection property of the specified [ListBox](/api/wisej.web/lists-and-grids/listbox.md).

| Parameter    | Type                                                                               | Description                                                                                       |
| ------------ | ---------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------- |
| **TListBox** |                                                                                    | The type of the list box, must inherit from [ListBox](/api/wisej.web/lists-and-grids/listbox.md). |
| **listBox**  | [TListBox](/api/wisej.web.markup/extensions/wisej.web.markup.listboxextensions.md) | The list box for which to set the IncrementalSelection property.                                  |
| **value**    | [Boolean](https://docs.microsoft.com/dotnet/api/system.boolean)                    | A boolean indicating whether incremental selection is enabled.                                    |

**Returns:** [TListBox](/api/wisej.web.markup/extensions/wisej.web.markup.listboxextensions.md). The modified list box with the updated IncrementalSelection property.

This method allows you to enable or disable incremental selection for the list box.

```csharp

myListBox.IncrementalSelection(true);

```

### ![](/files/lIX317sDtMTZJBi9oSIx) ItemHeight\<TListBox>(listBox, itemHeight)

Sets the ItemHeight property of the specified [ListBox](/api/wisej.web/lists-and-grids/listbox.md).

| Parameter      | Type                                                                               | Description                                                                                       |
| -------------- | ---------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------- |
| **TListBox**   |                                                                                    | The type of the list box, must inherit from [ListBox](/api/wisej.web/lists-and-grids/listbox.md). |
| **listBox**    | [TListBox](/api/wisej.web.markup/extensions/wisej.web.markup.listboxextensions.md) | The list box for which to set the ItemHeight property.                                            |
| **itemHeight** | [Int32](https://docs.microsoft.com/dotnet/api/system.int32)                        | The height of each item in the list box.                                                          |

**Returns:** [TListBox](/api/wisej.web.markup/extensions/wisej.web.markup.listboxextensions.md). The modified list box with the updated ItemHeight property.

This method allows you to specify the height of each item in the list box.

```csharp

myListBox.ItemHeight(20);

```

### ![](/files/lIX317sDtMTZJBi9oSIx) Items\<TListBox>(listBox, items)

Adds the specified items to the Items collection of the specified [ListBox](/api/wisej.web/lists-and-grids/listbox.md).

| Parameter    | Type                                                                               | Description                                                                                       |
| ------------ | ---------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------- |
| **TListBox** |                                                                                    | The type of the list box, must inherit from [ListBox](/api/wisej.web/lists-and-grids/listbox.md). |
| **listBox**  | [TListBox](/api/wisej.web.markup/extensions/wisej.web.markup.listboxextensions.md) | The list box to which the items should be added.                                                  |
| **items**    | [Object\[\]](https://docs.microsoft.com/dotnet/api/system.object)                  | An array of items to add to the list box.                                                         |

**Returns:** [TListBox](/api/wisej.web.markup/extensions/wisej.web.markup.listboxextensions.md). The modified list box with the added items.

This method allows you to add multiple items to the list box in one call.

```csharp

myListBox.Items("Item1", "Item2", "Item3");

```

### ![](/files/lIX317sDtMTZJBi9oSIx) LazyLoading\<TListBox>(listBox, value)

Sets the LazyLoading property of the specified [ListBox](/api/wisej.web/lists-and-grids/listbox.md).

| Parameter    | Type                                                                               | Description                                                                                       |
| ------------ | ---------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------- |
| **TListBox** |                                                                                    | The type of the list box, must inherit from [ListBox](/api/wisej.web/lists-and-grids/listbox.md). |
| **listBox**  | [TListBox](/api/wisej.web.markup/extensions/wisej.web.markup.listboxextensions.md) | The list box for which to set the LazyLoading property.                                           |
| **value**    | [Boolean](https://docs.microsoft.com/dotnet/api/system.boolean)                    | A boolean indicating whether lazy loading is enabled.                                             |

**Returns:** [TListBox](/api/wisej.web.markup/extensions/wisej.web.markup.listboxextensions.md). The modified list box with the updated LazyLoading property.

This method allows you to enable or disable lazy loading for the list box.

```csharp

myListBox.LazyLoading(true);

```

### ![](/files/lIX317sDtMTZJBi9oSIx) OnSelectedIndexChanged\<TListBox>(listBox, action)

Attaches an event handler for the SelectedIndexChanged event of the specified [ListBox](/api/wisej.web/lists-and-grids/listbox.md).

| Parameter    | Type                                                                               | Description                                                                                       |
| ------------ | ---------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------- |
| **TListBox** |                                                                                    | The type of the list box, must inherit from [ListBox](/api/wisej.web/lists-and-grids/listbox.md). |
| **listBox**  | [TListBox](/api/wisej.web.markup/extensions/wisej.web.markup.listboxextensions.md) | The list box to attach the event handler to.                                                      |
| **action**   | [Action\<TListBox>](https://docs.microsoft.com/dotnet/api/system.action-1)         | An action to execute when the SelectedIndex property changes.                                     |

**Returns:** [TListBox](/api/wisej.web.markup/extensions/wisej.web.markup.listboxextensions.md). The modified list box with the attached SelectedIndexChanged event handler.

This method allows you to execute a custom action whenever the SelectedIndex property of the list box changes.

```csharp

myListBox.OnSelectedIndexChanged(lb =>
{
AlertBox.Show("Selected index changed!");
});

```

### ![](/files/lIX317sDtMTZJBi9oSIx) OnSortedChanged\<TListBox>(listBox, action)

Attaches an event handler for the SortedChanged event of the specified [ListBox](/api/wisej.web/lists-and-grids/listbox.md).

| Parameter    | Type                                                                               | Description                                                                                       |
| ------------ | ---------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------- |
| **TListBox** |                                                                                    | The type of the list box, must inherit from [ListBox](/api/wisej.web/lists-and-grids/listbox.md). |
| **listBox**  | [TListBox](/api/wisej.web.markup/extensions/wisej.web.markup.listboxextensions.md) | The list box to attach the event handler to.                                                      |
| **action**   | [Action\<TListBox>](https://docs.microsoft.com/dotnet/api/system.action-1)         | An action to execute when the Sorted property changes.                                            |

**Returns:** [TListBox](/api/wisej.web.markup/extensions/wisej.web.markup.listboxextensions.md). The modified list box with the attached SortedChanged event handler.

This method allows you to execute a custom action whenever the Sorted property of the list box changes.

```csharp

myListBox.OnSortedChanged(lb =>
{
AlertBox.Show("Sorted property changed!");
});

```

### ![](/files/lIX317sDtMTZJBi9oSIx) OnToolClick\<TListBox>(listBox, action)

Attaches an event handler for the ToolClick event of the specified [ListBox](/api/wisej.web/lists-and-grids/listbox.md).

| Parameter    | Type                                                                                           | Description                                                                                       |
| ------------ | ---------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------- |
| **TListBox** |                                                                                                | The type of the list box, must inherit from [ListBox](/api/wisej.web/lists-and-grids/listbox.md). |
| **listBox**  | [TListBox](/api/wisej.web.markup/extensions/wisej.web.markup.listboxextensions.md)             | The list box to attach the event handler to.                                                      |
| **action**   | [Action\<TListBox, ToolClickEventArgs>](https://docs.microsoft.com/dotnet/api/system.action-2) | An action to execute when a tool in the list box is clicked.                                      |

**Returns:** [TListBox](/api/wisej.web.markup/extensions/wisej.web.markup.listboxextensions.md). The modified list box with the attached ToolClick event handler.

This method allows you to execute a custom action whenever a tool in the list box is clicked.

```csharp

myListBox.OnToolClick((lb, args) =>
{
AlertBox.Show("Tool clicked!");
});

```

### ![](/files/lIX317sDtMTZJBi9oSIx) Orientation\<TListBox>(listBox, orientation)

Sets the Orientation property of the specified [ListBox](/api/wisej.web/lists-and-grids/listbox.md).

| Parameter       | Type                                                                               | Description                                                                                       |
| --------------- | ---------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------- |
| **TListBox**    |                                                                                    | The type of the list box, must inherit from [ListBox](/api/wisej.web/lists-and-grids/listbox.md). |
| **listBox**     | [TListBox](/api/wisej.web.markup/extensions/wisej.web.markup.listboxextensions.md) | The list box for which to set the Orientation property.                                           |
| **orientation** | [Orientation](/api/wisej.web/enumerations/wisej.web.orientation.md)                | The [Orientation](#orientation``1) to set for the list box.                                       |

**Returns:** [TListBox](/api/wisej.web.markup/extensions/wisej.web.markup.listboxextensions.md). The modified list box with the updated Orientation property.

This method allows you to set the orientation for the list box, which determines how items are displayed.

```csharp

myListBox.Orientation(Orientation.Horizontal);

```

### ![](/files/lIX317sDtMTZJBi9oSIx) RightClickSelection\<TListBox>(listBox, value)

Sets the RightClickSelection property of the specified [ListBox](/api/wisej.web/lists-and-grids/listbox.md).

| Parameter    | Type                                                                               | Description                                                                                       |
| ------------ | ---------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------- |
| **TListBox** |                                                                                    | The type of the list box, must inherit from [ListBox](/api/wisej.web/lists-and-grids/listbox.md). |
| **listBox**  | [TListBox](/api/wisej.web.markup/extensions/wisej.web.markup.listboxextensions.md) | The list box for which to set the RightClickSelection property.                                   |
| **value**    | [Boolean](https://docs.microsoft.com/dotnet/api/system.boolean)                    | A boolean indicating whether right-click selection is enabled.                                    |

**Returns:** [TListBox](/api/wisej.web.markup/extensions/wisej.web.markup.listboxextensions.md). The modified list box with the updated RightClickSelection property.

This method allows you to enable or disable right-click selection for the list box.

```csharp

myListBox.RightClickSelection(true);

```

### ![](/files/lIX317sDtMTZJBi9oSIx) ScrollAlwaysVisible\<TListBox>(listBox, value)

Sets the ScrollAlwaysVisible property of the specified [ListBox](/api/wisej.web/lists-and-grids/listbox.md).

| Parameter    | Type                                                                               | Description                                                                                       |
| ------------ | ---------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------- |
| **TListBox** |                                                                                    | The type of the list box, must inherit from [ListBox](/api/wisej.web/lists-and-grids/listbox.md). |
| **listBox**  | [TListBox](/api/wisej.web.markup/extensions/wisej.web.markup.listboxextensions.md) | The list box for which to set the ScrollAlwaysVisible property.                                   |
| **value**    | [Boolean](https://docs.microsoft.com/dotnet/api/system.boolean)                    | A boolean indicating whether the scrollbar is always visible.                                     |

**Returns:** [TListBox](/api/wisej.web.markup/extensions/wisej.web.markup.listboxextensions.md). The modified list box with the updated ScrollAlwaysVisible property.

This method allows you to ensure the scrollbar is always visible, regardless of the number of items.

```csharp

myListBox.ScrollAlwaysVisible(true);

```

### ![](/files/lIX317sDtMTZJBi9oSIx) SelectedItem\<TListBox>(listBox, selectedItem)

Sets the SelectedItem property of the specified [ListBox](/api/wisej.web/lists-and-grids/listbox.md).

| Parameter        | Type                                                                               | Description                                                                                       |
| ---------------- | ---------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------- |
| **TListBox**     |                                                                                    | The type of the list box, must inherit from [ListBox](/api/wisej.web/lists-and-grids/listbox.md). |
| **listBox**      | [TListBox](/api/wisej.web.markup/extensions/wisej.web.markup.listboxextensions.md) | The list box for which to set the SelectedItem property.                                          |
| **selectedItem** | [Object](https://docs.microsoft.com/dotnet/api/system.object)                      | The item to select in the list box.                                                               |

**Returns:** [TListBox](/api/wisej.web.markup/extensions/wisej.web.markup.listboxextensions.md). The modified list box with the updated SelectedItem property.

This method allows you to specify the selected item in the list box.

```csharp

myListBox.SelectedItem(item);

```

### ![](/files/lIX317sDtMTZJBi9oSIx) SelectionMode\<TListBox>(listBox, selectionMode)

Sets the SelectionMode property of the specified [ListBox](/api/wisej.web/lists-and-grids/listbox.md).

| Parameter         | Type                                                                               | Description                                                                                       |
| ----------------- | ---------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------- |
| **TListBox**      |                                                                                    | The type of the list box, must inherit from [ListBox](/api/wisej.web/lists-and-grids/listbox.md). |
| **listBox**       | [TListBox](/api/wisej.web.markup/extensions/wisej.web.markup.listboxextensions.md) | The list box for which to set the SelectionMode property.                                         |
| **selectionMode** | [SelectionMode](/api/wisej.web/enumerations/wisej.web.selectionmode.md)            | The [SelectionMode](#selectionmode``1) to set for the list box.                                   |

**Returns:** [TListBox](/api/wisej.web.markup/extensions/wisej.web.markup.listboxextensions.md). The modified list box with the updated SelectionMode property.

This method allows you to specify the selection mode for the list box.

```csharp

myListBox.SelectionMode(SelectionMode.MultiExtended);

```

### ![](/files/lIX317sDtMTZJBi9oSIx) Sorted\<TListBox>(listBox, value)

Sets the Sorted property of the specified [ListBox](/api/wisej.web/lists-and-grids/listbox.md).

| Parameter    | Type                                                                               | Description                                                                                       |
| ------------ | ---------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------- |
| **TListBox** |                                                                                    | The type of the list box, must inherit from [ListBox](/api/wisej.web/lists-and-grids/listbox.md). |
| **listBox**  | [TListBox](/api/wisej.web.markup/extensions/wisej.web.markup.listboxextensions.md) | The list box for which to set the Sorted property.                                                |
| **value**    | [Boolean](https://docs.microsoft.com/dotnet/api/system.boolean)                    | A boolean indicating whether the list box is sorted.                                              |

**Returns:** [TListBox](/api/wisej.web.markup/extensions/wisej.web.markup.listboxextensions.md). The modified list box with the updated Sorted property.

This method allows you to specify whether the items in the list box should be sorted automatically.

```csharp

myListBox.Sorted(true);

```

### ![](/files/lIX317sDtMTZJBi9oSIx) Tools\<TListBox>(listBox, items)

Adds the specified tools to the Tools collection of the specified [ListBox](/api/wisej.web/lists-and-grids/listbox.md).

| Parameter    | Type                                                                               | Description                                                                                       |
| ------------ | ---------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------- |
| **TListBox** |                                                                                    | The type of the list box, must inherit from [ListBox](/api/wisej.web/lists-and-grids/listbox.md). |
| **listBox**  | [TListBox](/api/wisej.web.markup/extensions/wisej.web.markup.listboxextensions.md) | The list box to which the tools should be added.                                                  |
| **items**    | [ComponentTool\[\]](/api/wisej.web/editors/wisej.web.componenttool.md)             | An array of tools to add to the list box.                                                         |

**Returns:** [TListBox](/api/wisej.web.markup/extensions/wisej.web.markup.listboxextensions.md). The modified list box with the added tools.

This method allows you to add multiple tools to the list box in one call.

```csharp

myListBox.Tools(tool1, tool2, tool3);

```

### ![](/files/lIX317sDtMTZJBi9oSIx) TopIndex\<TListBox>(listBox, topIndex)

Sets the TopIndex property of the specified [ListBox](/api/wisej.web/lists-and-grids/listbox.md).

| Parameter    | Type                                                                               | Description                                                                                       |
| ------------ | ---------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------- |
| **TListBox** |                                                                                    | The type of the list box, must inherit from [ListBox](/api/wisej.web/lists-and-grids/listbox.md). |
| **listBox**  | [TListBox](/api/wisej.web.markup/extensions/wisej.web.markup.listboxextensions.md) | The list box for which to set the TopIndex property.                                              |
| **topIndex** | [Int32](https://docs.microsoft.com/dotnet/api/system.int32)                        | The index of the first visible item in the list box.                                              |

**Returns:** [TListBox](/api/wisej.web.markup/extensions/wisej.web.markup.listboxextensions.md). The modified list box with the updated TopIndex property.

This method allows you to specify the index of the first visible item in the list box.

```csharp

myListBox.TopIndex(5);

```


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