FrameworkElement.FindResource(Object) Method

Reference

Definition

Namespace:: System.Windows

Assembly:: PresentationFramework.dll

Important

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Searches for a resource with the specified key, and throws an exception if the requested resource is not found.

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

public object FindResource (object resourceKey);

member this.FindResource : obj -> obj

Public Function FindResource (resourceKey As Object) As Object

Parameters

resourceKey: Object

The key identifier for the requested resource.

Returns

Object

The requested resource. If no resource with the provided key was found, an exception is thrown. An UnsetValue value might also be returned in the exception case.

Exceptions

ResourceReferenceKeyNotFoundException

resourceKey was not found and an event handler does not exist for the UnhandledException event.

-or-

resourceKey was not found and the Handled property is false in the UnhandledException event.

ArgumentNullException

resourceKey is null.

Examples

The following example obtains a named resource and casts it to an appropriate type to fill a property.

void SetBGByResource(object sender, RoutedEventArgs e)
{
  Button b = sender as Button;
  b.Background = (Brush)this.FindResource("RainbowBrush");
}

Private Sub SetBGByResource(ByVal sender As Object, ByVal e As RoutedEventArgs)
  Dim b As Button = TryCast(sender, Button)
  b.Background = CType(Me.FindResource("RainbowBrush"), Brush)
End Sub

Remarks

Important

If you call this method for a key that cannot be found, an exception is thrown. If you do not want to handle exceptions that result from calling FindResource, call TryFindResource instead. TryFindResource returns null when a requested resource cannot be found, and does not throw an exception.

If the resource is not found on the calling element, the parent element in the logical tree is searched next, then the application, then themes, and finally system resources. This lookup methodology is identical to how the tree is searched if a resource were requested by a dynamic resource reference in markup. For more information about resource lookup, see XAML Resources.

Typically, you immediately cast a FindResource return value to the type of the property that you setting with the returned resource value.

Resource keys are not necessarily strings. For instance, styles for controls at the theme level are deliberately keyed to the Type of the control, and application or page styles for controls typically use this same key convention. For details, see Styling and Templating or XAML Resources.

Applies to

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