C# WPF 父控件通过使用可视化树找到子控件的示例代码

<ListBox Name="ListBox_1" HorizontalAlignment="Left" Height="299" Margin="10,10,0,0" VerticalAlignment="Top" Width="497" MouseDoubleClick="ListBox_1_OnMouseDoubleClick">
　　　　<ListBox.ItemTemplate>
　　　　　　<DataTemplate>
　　　　　　　　<Button Name="Button_1" Content="666"></Button>
　　　　　　</DataTemplate>
　　　　</ListBox.ItemTemplate>
</ListBox>

我在后台设置了显示了8行item，效果如下：

List<T> FindVisualChild<T>(DependencyObject obj) where T : DependencyObject
    {
      try
      {
        List<T> list = new List<T>();
        for (int i = 0; i < VisualTreeHelper.GetChildrenCount(obj); i++)
        {
          DependencyObject child = VisualTreeHelper.GetChild(obj, i);
          if (child is T)
          {
            list.Add((T)child);
            List<T> childOfChildren = FindVisualChild<T>(child);
            if (childOfChildren != null)
            {
              list.AddRange(childOfChildren);
            }
          }
          else
          {
            List<T> childOfChildren = FindVisualChild<T>(child);
            if (childOfChildren != null)
            {
              list.AddRange(childOfChildren);
            }
          }
        }
        return list;
      }
      catch (Exception)
      {
        //MessageBox.Show(ee.Message);
        return null;
      }
    }

先将上面的方法复制到你的项目当中，此时对于可视化树的应用已经完成一半了。

接下来上代码，通过可视化树双击ListBox的ltem把对应的button的Content值从666改成777：

private void ListBox_1_OnMouseDoubleClick(object sender, MouseButtonEventArgs e)
    {
      ListBoxItem myListBoxItem = (ListBoxItem)ListBox_1.ItemContainerGenerator.ContainerFromItem(ListBox_1.SelectedItem);
      List<Button> btnList = FindVisualChild<Button>(myListBoxItem);
      foreach (var item in btnList)
      {
        item.Content = "777";
      }
    }

一、查找某种类型的子控件，并返回一个List集合
public List<T> GetChildObjects<T>(DependencyObject obj, Type typename) where T : FrameworkElement
{
DependencyObject child = null;
List<T> childList = new List<T>();
for (int i = 0; i <= VisualTreeHelper.GetChildrenCount(obj) - 1; i++)
{
child = VisualTreeHelper.GetChild(obj, i);
if (child is T && (((T)child).GetType() == typename))
{
childList.Add((T)child);
}
childList.AddRange(GetChildObjects<T>(child,typename));
}
return childList;
}
调用：
List<Button> listButtons = GetChildObjects<Button>(parentPanel, typeof(Button)); //parentPanel就是xaml里定义的控件的x:name
二、通过名称查找子控件，并返回一个List集合
public List<T> GetChildObjects<T>(DependencyObject obj, string name) where T : FrameworkElement
{
DependencyObject child = null;
List<T> childList = new List<T>();
for (int i = 0; i <= VisualTreeHelper.GetChildrenCount(obj) - 1; i++)
{
child = VisualTreeHelper.GetChild(obj, i);
if (child is T && (((T)child).GetType() == name |string.IsNullOrEmpty(name)))
{
childList.Add((T)child);
}
childList.AddRange(GetChildObjects<T>(child,name));
}
return childList;
}
调用：
List<Button> listButtons = GetChildObjects<Button>(parentPanel, "button1");
三、通过名称查找某子控件：
public T GetChildObject<T>(DependencyObject obj, string name) where T : FrameworkElement
{
DependencyObject child = null;
T grandChild = null;
for (int i = 0; i <= VisualTreeHelper.GetChildrenCount(obj) - 1; i++)
{
child = VisualTreeHelper.GetChild(obj, i);
if (child is T && (((T)child).Name == name | string.IsNullOrEmpty(name)))
{
return (T)child;
}
else
{
grandChild = GetChildObject<T>(child, name);
if (grandChild != null)
return grandChild;
}
}
returnnull;
}
调用：
StackPanel sp = GetChildObject<StackPanel>(this.LayoutRoot, "spDemoPanel");
四、通过名称查找父控件
public T GetParentObject<T>(DependencyObject obj, string name) where T : FrameworkElement
{
DependencyObject parent = VisualTreeHelper.GetParent(obj);
while (parent != null)
{
if (parent is T && (((T)parent).Name == name | string.IsNullOrEmpty(name)))
{
return (T)parent;
}
parent = VisualTreeHelper.GetParent(parent);
}
returnnull;
}
调用：
Grid layoutGrid = VTHelper.GetParentObject<Grid>(this.spDemoPanel, "LayoutRoot");