发现里面Listbox.ItemTemplate控制（WPF C＃） [英] Find control inside Listbox.ItemTemplate (WPF C#)

问题描述

我有一些问题找到合适的内的TextBlock 控制的StackPanel 。
我的标记：

 <列表框名称=lstTimelineItemContainerStyle ={StaticResource的TwItemStyle}
 MouseDoubleClick =lstTimeline_MouseDoubleClick> 
< ListBox.ItemTemplate> 
<&DataTemplate的GT; 
< DockPanel中了maxWidth ={绑定的ElementName = lstTimeline，路径= ActualWidth的}> 
< BORDER保证金=10DockPanel.Dock =左BorderBrush =白
了borderThickness =1HEIGHT =48WIDTH =48的Horizo​​ntalAlignment =中心> 
<图像来源={结合缩略图，IsAsync = TRUE}HEIGHT =48WIDTH =48/> 
< /边框> 
< StackPanel的名称=stkPanel保证金=10DockPanel.Dock =右> 
< TextBlock的文本={绑定用户名}粗细=大胆字号=18/> 
< TextBlock的文本={结合文字}保证金=0,4,0,0字号=14
前景=＃c6de96TextWrapping =WrapWithOverflow/> 
< TextBlock的文本={结合ApproximateTime}字号=14
的FontFamily =格鲁吉亚fontstyle的=斜体前景=＃BBB/> 
< TextBlock的文本={结合ScreenName链接}NAME =lblScreenName字号=14
的FontFamily =格鲁吉亚fontstyle的=斜体前景=＃BBB
加载=lblScreenName_Loaded/> 
< / StackPanel的> 
< / DockPanel中> 
< / DataTemplate中> 
< /ListBox.ItemTemplate> 
< /列表框> 
  

我双击代码：

 私人无效lstTimeline_MouseDoubleClick（对象发件人，MouseButtonEventArgs E）
 {
 ListBoxItem的LBI =（lstTimeline.SelectedItem为ListBoxItem的）; 
 
的StackPanel项目= lbi.FindName（stkPanel）作为StackPanel的; 
如果（项目！= NULL）
 MessageBox.Show（StackPanel的空）; 
 TextBlock中的textBox = item.FindName（lblScreenName）作为TextBlock的; 
如果（textBox中！= NULL）
 MessageBox.Show（TextBlock的空）; 
 
 MessageBox.Show（textBox.Text）; 
} 
  

但的StackPanel 为空。如何找到的SelectedItem ？

正确的TextBlock

感谢您的帮助。

解决方案

  ListBoxItem的myListBoxItem =（ListBoxItem中）（lstUniqueIds.ItemContainerGenerator。 ContainerFromIndex（lstUniqueIds.SelectedIndex））; 
 ContentPresenter myContentPresenter = FindVisualChild< ContentPresenter>（myListBoxItem）; 
的DataTemplate myDataTemplate = myContentPresenter.ContentTemplate; 
复选框目标=（复选框）myDataTemplate.FindName（chkUniqueId，myContentPresenter）; 
如果（target.IsChecked）
 {
 target.IsChecked = FALSE; 
} 
，否则
 {
 target.IsChecked = TRUE; 
} 
  

功能 FindVisualChild CAN在MSDN的网页。 FrameworkTemplate.FindName方法为：

 私人childItem FindVisualChild< childItem>（DependencyObject的OBJ）
式childItem：DependencyObject的
 {
为（ INT I = 0; I< VisualTreeHelper.GetChildrenCount（OBJ）;我++）
 {
 DependencyObject的孩子= VisualTreeHelper.GetChild（OBJ，I）; 
如果（孩子= NULL&放大器;！&安培;孩子childItem）
回报（childItem）子女; 
，否则
 {
 childItem childOfChild = FindVisualChild< childItem>（小孩）; 
如果（childOfChild！= NULL）
返回childOfChild; 
} 
} 
返回NULL; 
} 
  

I have some problems finding the right TextBlock control inside a StackPanel. My markup:

<ListBox Name="lstTimeline" ItemContainerStyle="{StaticResource TwItemStyle}"
         MouseDoubleClick="lstTimeline_MouseDoubleClick">
    <ListBox.ItemTemplate>
        <DataTemplate>
            <DockPanel MaxWidth="{Binding ElementName=lstTimeline, Path=ActualWidth}">
                <Border Margin="10" DockPanel.Dock="Left"  BorderBrush="White"
                        BorderThickness="1" Height="48" Width="48" HorizontalAlignment="Center">
                    <Image Source="{Binding ThumbNail, IsAsync=True}" Height="48" Width="48" />
                </Border>
                <StackPanel Name="stkPanel" Margin="10" DockPanel.Dock="Right">
                    <TextBlock Text="{Binding UserName}" FontWeight="Bold" FontSize="18" />
                    <TextBlock Text="{Binding Text}" Margin="0,4,0,0" FontSize="14"
                               Foreground="#c6de96" TextWrapping="WrapWithOverflow" />
                    <TextBlock Text="{Binding ApproximateTime}" FontSize="14"
                               FontFamily="Georgia" FontStyle="Italic" Foreground="#BBB" />
                    <TextBlock Text="{Binding ScreenName}" Name="lblScreenName"  FontSize="14"
                               FontFamily="Georgia" FontStyle="Italic" Foreground="#BBB"
                               Loaded="lblScreenName_Loaded" />
                </StackPanel>
            </DockPanel>
        </DataTemplate>
    </ListBox.ItemTemplate>
</ListBox>

My double click code:

private void lstTimeline_MouseDoubleClick(object sender, MouseButtonEventArgs e)
{
    ListBoxItem lbi = (lstTimeline.SelectedItem as ListBoxItem);

    StackPanel item = lbi.FindName("stkPanel") as StackPanel;
    if (item != null)
        MessageBox.Show("StackPanel null");
    TextBlock textBox = item.FindName("lblScreenName") as TextBlock;
    if (textBox != null)
        MessageBox.Show("TextBlock null");

    MessageBox.Show(textBox.Text);
}

But the StackPanel is null. How do find the right TextBlock in SelectedItem?

Thanks for your help.

解决方案

ListBoxItem myListBoxItem = (ListBoxItem)(lstUniqueIds.ItemContainerGenerator.ContainerFromIndex(lstUniqueIds.SelectedIndex));
ContentPresenter myContentPresenter = FindVisualChild<ContentPresenter>(myListBoxItem);
DataTemplate myDataTemplate = myContentPresenter.ContentTemplate;
CheckBox target = (CheckBox)myDataTemplate.FindName("chkUniqueId", myContentPresenter);
if (target.IsChecked)
{
    target.IsChecked = false;
}
else
{
    target.IsChecked = true;
}

Function FindVisualChild can be found on the MSDN page FrameworkTemplate.FindName Method:

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;
}

这篇关于发现里面Listbox.ItemTemplate控制（WPF C＃）的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！