# Button Extensions

The Telerik suite provides built-in extensions that can change different behaviors of the button controls. This article will go through these extensions.

## Prevent Scrolling When DropDownButton is Opened

The drop down buttons allows you to prevent scrolling within the application while the drop down is opened. To enable this, set the `DropDownExtensions.HandleMouseWheelWhenOpen` [attached property](https://learn.microsoft.com/en-us/dotnet/desktop/wpf/properties/attached-properties-overview) to `True`.

This property is not supported when the button control has its `KeepOpen` property set to `True`.

**Set HandleMouseWheelWhenOpen attached property**

```XAML
<ScrollViewer Height="120">
    <StackPanel Height="800" Background="Bisque">
        <telerik:RadDropDownButton Content="Drop Down Button"  VerticalAlignment="Top" HorizontalAlignment="Left"
									   telerik:DropDownExtensions.HandleMouseWheelWhenOpen="True">
            <telerik:RadDropDownButton.DropDownContent>
                <telerik:RadListBox Height="50">
                    <telerik:RadListBoxItem Content="item 1"/>
                    <telerik:RadListBoxItem Content="item 2"/>
                    <telerik:RadListBoxItem Content="item 3"/>
                    <telerik:RadListBoxItem Content="item 4"/>
                    <telerik:RadListBoxItem Content="item 5"/>
                    <telerik:RadListBoxItem Content="item 6"/>
                    <telerik:RadListBoxItem Content="item 7"/>
                    <telerik:RadListBoxItem Content="item 8"/>
                </telerik:RadListBox>
            </telerik:RadDropDownButton.DropDownContent>
        </telerik:RadDropDownButton>
    </StackPanel>
</ScrollViewer>
```

The `DropDownExtensions.HandleMouseWheelWhenOpen` property is supported by the following controls - `RadDropDownButton`, `RadSplitButton`, `RadColorPicker`, `RadTimeSpanPicker`, `RadDateTimePicker`, `RadBreadCrumb`.

## Focus DropDown Content When DropDown is Opened

To focus the content element in the drop down content of a RadDropDownButton, set the `DropDownButtonExtensions.FocusContentOnOpen` [attached property](https://learn.microsoft.com/en-us/dotnet/desktop/wpf/properties/attached-properties-overview) to `True`.

**Set FocusContentOnOpen attached property**

```XAML
<telerik:RadDropDownButton Content="Drop Down Button" VerticalAlignment="Top" HorizontalAlignment="Left" 
							   telerik:DropDownButtonExtensions.FocusContentOnOpen="True">
    <telerik:RadDropDownButton.DropDownContent>
        <telerik:RadListBox >
            <telerik:RadListBoxItem Content="item 1"/>
            <telerik:RadListBoxItem Content="item 2"/>
            <telerik:RadListBoxItem Content="item 3"/>
            <telerik:RadListBoxItem Content="item 4"/>
        </telerik:RadListBox>
    </telerik:RadDropDownButton.DropDownContent>
</telerik:RadDropDownButton>
```

## See Also

* [EventToCommandBehavior](https://www.telerik.com/products/wpf/documentation/common-information/mvvm-helpers/common-event-to-command-behavior)
* [Attached Behavior](https://www.telerik.com/products/wpf/documentation/common-information/mvvm-helpers/common-attached-behaviors)
* [DelegateCommand](https://www.telerik.com/products/wpf/documentation/common-information/mvvm-helpers/common-delegate-command)