检索 ItemsControl 的子项

Question

在上面的 XAML 代码中，我使用下面的代码获取子项（ItemsCotnrol x:Name="PointsList) 并获得计数 = 0。你能帮我解决这个问题吗？

        int count = VisualTreeHelper.GetChildrenCount(pointsList);
        if (count > 0)
        {
            for (int i = 0; i < count; i++)
            {
                UIElement child = VisualTreeHelper.GetChild(pointsList, i) as UIElement;
                if (child.GetType() == typeof(TextBlock))
                {
                    textPoints = child as TextBlock;
                    break;
                }
            }
        }

pointsList 定义如下。

pointsList = (ItemsControl)GetTemplateChild("PointsList"); 

Answer 1

当您在后面的代码中使用 myPoints 时，您可以使用 ItemContainerGeneratorGetContainerForItem。只需传递您的一件物品即可获得容器。

使用辅助方法获取每个项目的文本块的代码GetChild：

for (int i = 0; i < PointsList.Items.Count; i++)
{
     // Note this part is only working for controls where all items are loaded  
     // and generated. You can check that with ItemContainerGenerator.Status
     // If you are planning to use VirtualizingStackPanel make sure this 
     // part of code will be only executed on generated items.
     var container = PointsList.ItemContainerGenerator.ContainerFromIndex(i);
     TextBlock t = GetChild<TextBlock>(container);
}

从DependencyObject中获取子对象的方法：

public T GetChild<T>(DependencyObject obj) where T : DependencyObject
{
    DependencyObject child = null;
    for (Int32 i = 0; i < VisualTreeHelper.GetChildrenCount(obj); i++)
    {
         child = VisualTreeHelper.GetChild(obj, i);
         if (child != null && child.GetType() == typeof(T))
         {
             break;
         }
         else if (child != null)
         {
             child = GetChild<T>(child);
             if (child != null && child.GetType() == typeof(T))
             {
                 break;
             }
         }
     }
     return child as T;
 }