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--- swdev:dotnet:wpf:datatemplates [2012/11/14 13:00]
smayr created
+++ swdev:dotnet:wpf:datatemplates [2012/12/07 17:15] (current)
smayr [Example 2]
@@ Line 24: / Line 24: @@
 }
 </code>
+== How to: Find DataTemplate-Generated Elements ==
+To find elements generated by a DataTemplate:
+<code xml>
+<DataTemplate x:Key="myDataTemplate">
+  <TextBlock Name="textBlock" FontSize="14" Foreground="Blue">
+    <TextBlock.Text>
+      <Binding XPath="Title"/>
+    </TextBlock.Text>
+  </TextBlock>
+</DataTemplate>
+...
+<ListBox Name="myListBox" ItemTemplate="{StaticResource myDataTemplate}"
+         IsSynchronizedWithCurrentItem="True">
+  <ListBox.ItemsSource>
+    <Binding Source="{StaticResource InventoryData}" XPath="Books/Book"/>
+  </ListBox.ItemsSource>
+</ListBox>
+</code>
+We have to find the ContentPresenter first:
+<code csharp>
+// Getting the currently selected ListBoxItem
+// Note that the ListBox must have
+// IsSynchronizedWithCurrentItem set to True for this to work
+ListBoxItem myListBoxItem =
+    (ListBoxItem)(myListBox.ItemContainerGenerator.ContainerFromItem(myListBox.Items.CurrentItem));
+// Getting the ContentPresenter of myListBoxItem
+ContentPresenter myContentPresenter = FindVisualChild<ContentPresenter>(myListBoxItem);
+// Finding textBlock from the DataTemplate that is set on that ContentPresenter
+DataTemplate myDataTemplate = myContentPresenter.ContentTemplate;
+TextBlock myTextBlock = (TextBlock)myDataTemplate.FindName("textBlock", myContentPresenter);
+// Do something to the DataTemplate-generated TextBlock
+MessageBox.Show("The text of the TextBlock of the selected list item: "
+    + myTextBlock.Text);
+. . .
+private childItem FindVisualChild<childItem>(DependencyObject obj)
+    where childItem : DependencyObject
+{
+    for (int i = 0; i < VisualTreeHelper.GetChildrenCount(obj); i++)
+    {
+        DependencyObject child = VisualTreeHelper.GetChild(obj, i);
+        if (child != null && child is childItem)
+            return (childItem)child;
+        else
+        {
+            childItem childOfChild = FindVisualChild<childItem>(child);
+            if (childOfChild != null)
+                return childOfChild;
+        }
+    }
+    return null;
+}
+</code>
+Source: [[http://msdn.microsoft.com/en-us/library/system.windows.frameworktemplate.findname.aspx|MSDN: FrameworkTemplate.FindName Method]]
+=== Example 1 ===
+For a ListBoxItem:
+<code xml>
+<ListBox Name="listBox">
+    <ListBox.ItemTemplate>
+        <DataTemplate DataType="x:Type local:NumericIconDefinition">
+           <Grid>
+                <ComboBox Name="IconComboBox"/>
+           </Grid>
+        </DataTemplate>
+    </ListBox.ItemTemplate>
+</ListBox>
+</code>
+<code csharp>
+ListBoxItem lbi = (ListBoxItem)listBox.ItemContainerGenerator.ContainerFromIndex(IndexInListBox);
+ComboBox cb = (ComboBox)listBox.ItemTemplate.FindName("IconComboBox", lbi);
+</code>
+=== Example 2 ===
+For a ListBoxItem:
+<code xml>
+<Window.Resources>
+    <local:GreekGods x:Key="greekGods"/>
+    <DataTemplate x:Key="itemTemplate">
+        <TextBlock Text="{Binding Path=Name}" />
+    </DataTemplate>
+</Window.Resources>
+. . .
+<ListBox ItemsSource="{StaticResource greekGods}" ItemTemplate="{StaticResource itemTemplate}" Name="listBox"/>
+</code>
+<code csharp>
+// To get GreekGod object
+GreekGod greekGod = (GreekGod)(listBox.Items[0]);
+// To get ListBoxItem container holding object GreekGod
+ListBoxItem lbi1 = (ListBoxItem)(listBox.ItemContainerGenerator.ContainerFromIndex(0));
+ListBoxItem lbi2 = (ListBoxItem)(listBox.ItemContainerGenerator.ContainerFromItem(listBox.Items.CurrentItem));
+</code>
+Source: [[http://www.zagstudio.com/blog/7#.UMESToM72dI|ZAG Log: How to get a ListBoxItem from a data bound ListBox]]