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UIElementCollection.IndexOf Method

Returns the index position of a specified element in a UIElementCollection.

Namespace: System.Windows.Controls
Assembly: PresentationFramework (in presentationframework.dll)

public virtual int IndexOf (
	UIElement element
)
public int IndexOf (
	UIElement element
)
public function IndexOf (
	element : UIElement
) : int
You cannot use methods in XAML.

Parameters

element

The element whose index position is required.

Return Value

The index position of the element.

The following example finds the index position of a UIElement within a UIElementCollection. For the complete sample, see Finding the Index of an Element in a Panel Sample.

<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);
}

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0

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