FrameworkElement.TryFindResource(Object) Method

Definition

Namespace:

System.Windows

Assembly:

PresentationFramework.dll

Searches for a resource with the specified key, and returns that resource if found.

public:
 System::Object ^ TryFindResource(System::Object ^ resourceKey);

public object TryFindResource (object resourceKey);

member this.TryFindResource : obj -> obj

Public Function TryFindResource (resourceKey As Object) As Object

Parameters

resourceKey

Object

The key identifier of the resource to be found.

Returns

Object

The found resource, or null if no resource with the provided key is found.

Examples

The following example is implemented as a button handler, where the button being clicked sets its background to a resource-defined brush obtained by calling TryFindResource on itself. This walks the element tree and finds the resource (the resource itself is defined in XAML and is not shown).

void TryFind(object sender, RoutedEventArgs e)  {
    Button b = e.Source as Button;
    b.Background = (Brush)b.TryFindResource("customBrush");
}

Private Sub TryFind(ByVal sender As Object, ByVal e As RoutedEventArgs)
    Dim b As Button = TryCast(e.Source, Button)
    b.Background = CType(b.TryFindResource("customBrush"), Brush)
End Sub

Remarks

If the resource is not found on the calling element, the parent resource tree is searched upward through the logical tree, in the same way that the tree would be searched if a resource were requested by key at run time. The method returns null only if no resource of that key existed anywhere in the resource tree, per the existing conditions of the tree at the time that TryFindResource is called.

Typically you would immediately cast the return value to the type of the property that you were attempting to set with the returned resource value.

The FindResource method has similar behavior, except that it throws an exception if no resource with the provided key was returned.

See also

• FindResource(Object)