ComboBox in Uno.UI

The ComboBox is designed to select a value in a set of items. For more info about its usage, please refer the microsoft documentation

Customize the placement of the Drop-Down UNO ONLY feature

By default when opening a combo, UWP aligns the drop down in order to keep the selected item at the same location. So it means that if the currently selected value is the last one in the list, the drop down will appear above the ComboBox. If there isn't any selected item, the drop down will appear centered over the ComboBox.

On Uno you can change this behavior.

Change the default value for all the ComboBox in you application

The default placement for all ComboBox instances can be changed by setting the feature flag in the startup of your app (app.cs or app.xaml.cs) :

Uno.UI.FeatureConfiguration.ComboBox.DefaultDropDownPreferredPlacement = DropDownPlacement.Below;

Change only for a specific ComboBox

<Page
	[...]
	xmlns:not_win="using:Uno.UI.Xaml.Controls"
    mc:Ignorable="d not_win">

	<ComboBox
		ItemsSource="12345"
		not_win:ComboBox.DropDownPreferredPlacement="Below" />