[英]How to get element in code behind from DataTemplate
I have a FlipView control with the DataTemplate defined as below:我有一个 FlipView 控件,其 DataTemplate 定义如下:
<FlipView x:Name="FlipView5Horizontal" Width="480" Height="270" BorderBrush="Black" BorderThickness="1" Style="{StaticResource FlipViewStyle1}">
<FlipView.ItemTemplate>
<DataTemplate>
<Grid>
<Image Width="480" Name="xxxImage" Height="270" Source="{Binding Image}" Stretch="UniformToFill"/>
<Border Name="xxxBorder" Background="#A5000000" Height="80" VerticalAlignment="Bottom">
<TextBlock Name="xxxTB" Text="{Binding Title}" FontFamily="Segoe UI" FontSize="26.667" Foreground="#CCFFFFFF" Padding="15,20"/>
</Border>
</Grid>
</DataTemplate>
</FlipView.ItemTemplate>
</FlipView>
In my code behind, I need to have access to the TextBlock named "xxxTB".在我后面的代码中,我需要访问名为“xxxTB”的 TextBlock。 Here is my code to do that:
这是我的代码:
public IEnumerable<T> FindVisualChildren<T>(DependencyObject depObj) where T : DependencyObject
{
if (depObj != null)
{
for (int i = 0; i < VisualTreeHelper.GetChildrenCount(depObj); i++)
{
DependencyObject child = VisualTreeHelper.GetChild(depObj, i);
if (child != null && child is T)
{
yield return (T)child;
}
foreach (T childOfChild in FindVisualChildren<T>(child))
{
yield return childOfChild;
}
}
}
}
public void TestMethod()
{
foreach (var item in FindVisualChildren<TextBlock>(this))
{
if (timeLine.Name == "xxxTB")
{ }
}
}
But, when it finds the FlipView in the VisualTree, it returns from: for (int i = 0; i < VisualTreeHelper.GetChildrenCount(depObj); i++)
because VisualTreeHelper.GetChildrenCount(depObj)
does not return anything.但是,当它在 VisualTree 中找到 FlipView 时,它返回:
for (int i = 0; i < VisualTreeHelper.GetChildrenCount(depObj); i++)
因为VisualTreeHelper.GetChildrenCount(depObj)
不返回任何内容。
Any idea?任何的想法?
So here is a working solution:所以这是一个有效的解决方案:
public void TestMethod()
{
DataTemplate dt = FlipView5Horizontal.ItemTemplate;
DependencyObject dio = dt.LoadContent();
foreach (var timeLine in FindVisualChildren<TextBlock>(dio)) //FindVisualTree is defined in the question :)
{
if (timeLine.Name == "xxxTB")
{ }
}
}
Now, I am able to load the control at least.现在,我至少能够加载控件。 (However, I read that this trick should not be used in the overridden method OnApplyTemplate for some reason).
(但是,我读到由于某种原因,不应在重写的方法 OnApplyTemplate 中使用此技巧)。
Try this尝试这个
ContentPresenter cp = GetFrameworkElementByName<ContentPresenter>(FlipView5Horizontal);
DataTemplate dt = FlipView5Horizontal.ItemTemplate;
TextBlock l = (dt.FindName("xxxTB", cp)) as TextBlock;
private static T GetFrameworkElementByName<T>(FrameworkElement referenceElement) where T : FrameworkElement
{
FrameworkElement child = null;
for (Int32 i = 0; i < VisualTreeHelper.GetChildrenCount(referenceElement); i++)
{
child = VisualTreeHelper.GetChild(referenceElement, i) as FrameworkElement;
System.Diagnostics.Debug.WriteLine(child);
if (child != null && child.GetType() == typeof(T))
{
break;
}
else if (child != null)
{
child = GetFrameworkElementByName<T>(child);
if (child != null && child.GetType() == typeof(T))
{
break;
}
}
}
return child as T;
}
You can try this:你可以试试这个:
var textblock = IteratingKeyboardChildren(g, keyName);
Border IteratingKeyboardChildren(Grid g, string keyName)
{
for (int i = 0; i < VisualTreeHelper.GetChildrenCount(g); i++)
{
var child = VisualTreeHelper.GetChild(g, i);
if (child is TextBlock )
{
if ((child as TextBlock ).Tag.ToString().Equals( keyName))
return child as TextBlock ;
}
}
return null;
}
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