Редагувати

Поділитися через


UIElement3D.Focus Method

Definition

Attempts to set the logical focus on this element.

public:
 virtual bool Focus();
public bool Focus ();
abstract member Focus : unit -> bool
override this.Focus : unit -> bool
Public Function Focus () As Boolean

Returns

true if both logical and keyboard focus were set to this element; false if only logical focus was set.

Implements

Remarks

To be focusable, Focusable and IsEnabled must both be true.

Even if an element is focusable and enabled, event handling within a specific tree, (such as for a composite control) might respond to the preview focus events by not allowing focus there, thus this method would return false.

If calling Focus returns true, IsKeyboardFocused and IsKeyboardFocusWithin are also true.

If the related properties are not already true, when you call Focus, one or more of the following events are raised in the following order: PreviewLostKeyboardFocus, PreviewGotKeyboardFocus (source is the new focus target), IsKeyboardFocusedChanged, IsKeyboardFocusWithinChanged, LostKeyboardFocus, GotKeyboardFocus (source is the new focus target).

In order for this call to be successful, some other element in the application needed to have focus previously.

Focus in general is governed by two separate concepts: keyboard focus and logical focus, which are not always identical. This method sets the logical focus, and also attempts to set the keyboard focus. There is no programmatic means to set keyboard focus specifically, this happens due to user input. For more information, see Input Overview.

Applies to