Class ComboBox
A Selector with an editable text field that live-filters items by a case-insensitive
Contains match against DisplayMemberPath - selection-only, not free text
entry (see the class remarks on ItemsSource).
public class ComboBox : Selector, INotifyPropertyChanging, IBindingTarget, INotifyPropertyChanged, INotifyFocusChanged, IContainerLayout, IVirtualizingScrollInfo- Inheritance
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ComboBox
- Implements
- Inherited Members
- Extension Methods
Remarks
ItemsSource shadows (does not override - ItemsSource isn't virtual) the inherited property, the same way Padding already shadows Padding: this control's real, full source is held here, and the base ItemsSource is kept pointed at whatever subset currently matches the filter text. SelectedItem/SelectedIndex reflect the filtered subset only while actively filtering - full selection is restored on every commit path (a matching Enter, or a revert via Escape/non-matching Enter).
Constructors
ComboBox()
Initializes a new instance of the ComboBox class.
public ComboBox()Properties
ItemsSource
Gets or sets the collection this control's items are drawn from - shadows ItemsSource to apply Text's filter on top.
public IEnumerable? ItemsSource { get; set; }Property Value
Remarks
Because the base ItemsSource is only ever pointed at a throwaway filtered snapshot, ItemsControl's own INotifyCollectionChanged observation never sees the real collection - so this setter subscribes to it here instead, re-running the filter whenever it changes (see OnDetached() for the matching unsubscribe).
Methods
OnActivate()
Invoked by Canvas for an activation press (Enter, gamepad A) while this element or one of its descendants has focus.
protected override bool OnActivate()Returns
- bool
true to claim the press; Canvas then stops calling further ancestors. The base implementation returns false.
Remarks
Closed: opens the popup. Open with a valid HighlightedIndex: commits it to SelectedIndex and closes. Always claims the press.
OnDetached()
Raises the Detached event.
protected override void OnDetached()Remarks
Propagates null to every element in GetVisualChildren(), mirroring OnAttached() - see its remarks.
OnNavigationCloseModal(object?, EventArgs)
Handles Escape/gamepad-B while the focus gate is focused - closes the popup without changing SelectedIndex.
protected override void OnNavigationCloseModal(object? sender, EventArgs e)