UIElementCollection.IndexOf(UIElement) Method
Definition
Important
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Returns the index position of a specified element in a UIElementCollection.
public:
virtual int IndexOf(System::Windows::UIElement ^ element);
public virtual int IndexOf (System.Windows.UIElement element);
abstract member IndexOf : System.Windows.UIElement -> int
override this.IndexOf : System.Windows.UIElement -> int
Public Overridable Function IndexOf (element As UIElement) As Integer
Parameters
- element
- UIElement
The element whose index position is required.
Returns
The index position of the element. -1 if the element is not in the collection.
Examples
The following example finds the index position of a UIElement within a UIElementCollection.
<DockPanel Name="ParentElement">
<TextBlock DockPanel.Dock="Top" Name="TxtDisplay"></TextBlock>
<Button DockPanel.Dock="Top" Click="FindIndex">What is the Index Number
of the Element Just Added?</Button>
<DockPanel Name="MainDisplayPanel">
<TextBlock DockPanel.Dock="Top">Text 1</TextBlock>
<TextBlock DockPanel.Dock="Top">Text 2</TextBlock>
</DockPanel>
</DockPanel>
...
private int c_counter = 0;
void FindIndex(object sender, RoutedEventArgs e)
{
c_counter+=1;
// Create a new Text element.
TextBlock newText = new TextBlock();
// Add this element to the UIElementCollection of the DockPanel element.
MainDisplayPanel.Children.Add(newText);
// Add a text node under the Text element. This text is displayed.
newText.Text = "New element #" + c_counter;
DockPanel.SetDock(newText,Dock.Top);
// Display the Index number of the new element.
TxtDisplay.Text = "The Index of the new element is " + MainDisplayPanel.Children.IndexOf(newText);
}
Dim c_counter as Integer = 0
Private Sub FindIndex(ByVal sender As Object, ByVal args As RoutedEventArgs)
Try
Dim newText As TextBlock = New TextBlock()
c_counter = c_counter + 1
' Add this element to the UIElementCollection of the DockPanel element.
MainDisplayPanel.Children.Add(newText)
' Add a text node under the Text element. This text is displayed.
newText.Text = "New element #" & CStr(c_counter)
DockPanel.SetDock(newText, Dock.Top)
' Display the Index number of the new element.
TxtDisplay.Text = "The Index of the new element is " & MainDisplayPanel.Children.IndexOf(newText)
Catch ex As System.Exception
System.Windows.MessageBox.Show(ex.Message)
End Try
End Sub
Applies to
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