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ContentElement.Focus Method

Attempts to set focus to this element.

Namespace:  System.Windows
Assembly:  PresentationCore (in PresentationCore.dll)

public bool Focus()

Return Value

Type: System.Boolean
true if keyboard focus could be set to this element; false if this method call did not force focus.

Implements

IInputElement.Focus()

To be focusable, Focusable and IsEnabled must both be true. Note that nearly all ContentElement derived classes are not Focusable by default.

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.

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. There is no programmatic means to set keyboard focus specifically; keyboard focus is determined by user input. For more information, see Focus Overview and Input Overview.

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).

The following example is a page-loaded event handler that finds a specified named paragraph in the document and sets focus to it. Paragraphs are not focusable by default; this particular paragraph had a style applied (not shown) that used a style Setter to make it focusable.


void FocusOnParagraph(object sender, RoutedEventArgs e)
{
  ContentElement ce = this.FindName("focusableP") as ContentElement;
  ce.Focus();
}


.NET Framework

Supported in: 4, 3.5, 3.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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