ItemContainerGenerator Class

Inheritance Hierarchy

System.Object
  System.Windows.Controls.ItemContainerGenerator

Syntax

'Declaration
Public NotInheritable Class ItemContainerGenerator _
    Implements IRecyclingItemContainerGenerator, IItemContainerGenerator

public sealed class ItemContainerGenerator : IRecyclingItemContainerGenerator, 
    IItemContainerGenerator

Methods

	Name	Description
	ContainerFromIndex	Returns the container for the item at the specified index within the ItemCollection.
	ContainerFromItem	Returns the container corresponding to the specified item.
	Equals(Object)	Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
	Finalize	Allows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.)
	GeneratorPositionFromIndex	Gets the generated position of the item at the specified index.
	GetHashCode	Serves as a hash function for a particular type. (Inherited from Object.)
	GetType	Gets the Type of the current instance. (Inherited from Object.)
	IndexFromContainer	Returns the index to the item that has the specified, generated container.
	IndexFromGeneratorPosition	Returns the index that maps to the specified GeneratorPosition.
	ItemFromContainer	Returns the item that corresponds to the specified, generated container.
	MemberwiseClone	Creates a shallow copy of the current Object. (Inherited from Object.)
	ToString	Returns a string that represents the current object. (Inherited from Object.)

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Events

	Name	Description
	ItemsChanged	Occurs when the contents of the items collection changes.

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Explicit Interface Implementations

	Name	Description
	IItemContainerGenerator.GenerateNext	Returns the container element used to display the next item, and whether the container element has been newly generated (realized).
	IItemContainerGenerator.GetItemContainerGeneratorForPanel	Returns the ItemContainerGenerator appropriate for use by the specified panel.
	IItemContainerGenerator.PrepareItemContainer	Prepares the specified element as the container for the corresponding item.
	IItemContainerGenerator.Remove	Removes one or more generated (realized) items.
	IItemContainerGenerator.RemoveAll	Removes all generated (realized) items.
	IItemContainerGenerator.StartAt	Prepares the generator to generate items, starting at the specified GeneratorPosition, and in the specified GeneratorDirection, and controlling whether or not to start at a generated (realized) item.
	IRecyclingItemContainerGenerator.Recycle	Disassociates item containers from their data items and saves the containers so they can be reused later for other data items.

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Remarks

The ItemContainerGenerator class maintains associations between items controls and their item containers, such as ListBox and ListBoxItem. If a control has an associated ItemContainerGenerator, you will be able to retrieve it through a property on the control

You can use the ItemContainerGenerator to retrieve items based on their index or containers by specifying the data item. For example, if you have a data-bound TreeView, and you want to get a TreeViewItem based on its index, you can use the ContainerFromIndex method. If you want to retrieve the data item, use ItemFromContainer method.

Examples

The following example shows how to retrieve an ItemContainerGenerator for a TreeView object and use the ContainerFromIndex method.

Run this sample

Public Sub New()
    InitializeComponent()
    Dim myItems As String() = New String() {"Item 1", "Item 2", "Item 3", "Item 4", "Item 5"}
    myTreeView.DataContext = myItems
End Sub
Shared count As Integer = 1
Private Sub Button_Click(ByVal sender As Object, ByVal e As RoutedEventArgs)
    Dim item As TreeViewItem = DirectCast(myTreeView.ItemContainerGenerator.ContainerFromIndex(3), TreeViewItem)
    item.IsExpanded = True
    If count < 5 Then
        item.Items.Add("Child " & count.ToString())
        count += 1
    End If
End Sub

public MainPage()
{
    InitializeComponent();
    string[] myItems = new string[]{"Item 1", "Item 2", "Item 3", "Item 4", "Item 5"};
    myTreeView.DataContext = myItems;
}
static int count = 1;
private void Button_Click(object sender, RoutedEventArgs e)
{
    TreeViewItem item = (TreeViewItem)myTreeView.ItemContainerGenerator.ContainerFromIndex(3);
    item.IsExpanded = true;
    if (count < 5)
    {
        item.Items.Add("Child " + count.ToString());
        count++;
    }
}

<StackPanel x:Name="LayoutRoot" Background="White">
    <sdk:TreeView x:Name="myTreeView" Width="200" ItemsSource="{Binding}" Margin="5"/>
    <Button Content="Add Child to Item 4" Width="150" Click="Button_Click"/>
</StackPanel>

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

See Also

Reference