VisualTreeHelper.GetChildrenCount返回0？

我正在使用VisualTreeHelper.GetChildrenCount()来查找子控件，但它总是返回0。

这是我的代码

       //Some Controls here       

C＃代码：

 channelRecordTimeItems.ItemContainerGenerator.StatusChanged += ChannelRecordTimeItemsStatusChangedEventHandler; private void ChannelRecordTimeItemsStatusChangedEventHandler(Object sender, EventArgs e) { if (channelRecordTimeItems.ItemContainerGenerator.Status == GeneratorStatus.ContainersGenerated) { if (channelRecordTimeItems.HasItems) { DependencyObject dependencyObject = null; Grid gridHighlightRecordData = null; for (int i = 0; i < channelRecordTimeItems.Items.Count; i++) { dependencyObject = channelRecordTimeItems.ItemContainerGenerator.ContainerFromIndex(i); //dependencyObject != null if (dependencyObject != null) { Grid hoursLines = FindElement.FindChild(dependencyObject, "hoursLines"); //hoursLines = null } } } } } public static T FindChild(DependencyObject parent, string childName) where T : DependencyObject { // Confirm parent and childName are valid. if (parent == null) return null; T foundChild = null; int childrenCount = VisualTreeHelper.GetChildrenCount(parent); //Return 0 here for (int i = 0; i < childrenCount; i++) { var child = VisualTreeHelper.GetChild(parent, i); // If the child is not of the request child type child T childType = child as T; if (childType == null) { // recursively drill down the tree foundChild = FindChild(child, childName); // If the child is found, break so we do not overwrite the found child. if (foundChild != null) break; } else if (!string.IsNullOrEmpty(childName)) { var frameworkElement = child as FrameworkElement; // If the child's name is set for search if (frameworkElement != null && frameworkElement.Name == childName) { // if the child's name is of the request name foundChild = (T)child; break; } } else { // child element found. foundChild = (T)child; break; } } return foundChild; } 

VisualTreeHelper.GetChildrenCount()始终返回0，

在这里构建项目的代码

 List listChannelRecordTimeItemData = new List(); for(int i = 0; i < 5; i++) { ChannelRecordTimeItemData item = new ChannelRecordTimeItemData(); listChannelRecordTimeItemData.Add(ChannelRecordTimeItemData); } channelRecordTimeItems.ItemsSource = listChannelRecordTimeItemData; channelRecordTimeItems.Items.Refresh(); 

我在论坛和互联网上搜索过，但我无法解决，有人可以帮助我吗？

非常感谢！

T＆T

Answer 1

问题是，当ItemContainerGenerator发出ContainersGenerated状态信号时，已创建容器（ ContentPresenter ）但尚未加载。 特别是数据模板尚未应用于ContentPresenter，因此可视化树中没有任何内容。

您可以通过在生成的容器上循环时添加一个Loaded事件处理程序来解决这个问题。

 private void ItemContainerGeneratorStatusChanged(object sender, EventArgs e) { if (itemsControl.ItemContainerGenerator.Status == GeneratorStatus.ContainersGenerated) { var containers = itemsControl.Items.Cast 

Answer 2

如果您使用Caliburn.Micro，这将对您有所帮助。 对于Viewmodel，基类应该是Screen，然后只有VisualTreeHelper.GetChildrenCount（）给出no.of childs。（因为Screen将激活所有子项

或者以其他方式（FrameworkElement）YourParent）.ApplyTemplate（）方法