WPF ItemsControl 从数据对象获取容器（TreeView、多选）

发布于 2024-10-27 00:24:48 字数 668 浏览 4 评论 0原文

如何获取 WPF ItemsControl 中对象的容器。

我正在编写一个带有可绑定 SelectedItem 和 SelectedItems 依赖属性的多选树视图。这么长时间以来，一切都很好。唯一的问题是，当我第二次按下 ctrl 键单击树中的某个项目时，不应选择该项目，而应选择上一次选择的项目。 TreeView 包含一个名为 ChangeSelection 的私有方法。据我了解，第一个参数是 Container，第二个参数是 TreeViewItem，最后一个参数是选择或不选择项目的位置。

我通过捕获 SelectedItemChanged 事件来实现多重选择。

此代码适用于新选定的项目

private void OnSelectedItemChanged(object sender, RoutedPropertyChangedEventArgs<object> e)
{
    var view = ItemContainerGenerator.ContainerFromItem(e.NewValue) as TreeViewItem;
    // ...
}

，但如果我想从 ObservableCollection 中保存的项目获取 TreeViewItem...它将不起作用。

编辑：好的，正如我发现的那样。上面的代码仅适用于第一级项目......

原文

How can I get the Container for an object in WPF ItemsControl.

I am writing a multiselect treeview with bindable SelectedItem und SelectedItems Dependency Properties. So long everything works just fine. The only thing is, when I click on an item in the tree with pressed ctrl a second time this item should not be selected but the last previous selected item. The TreeView contains a private Method called ChangeSelection. As far as i understand the first parameter is the Container, the second is the TreeViewItem and the last wherether the item shall be selected or not.

I implement the multiselection with catching the SelectedItemChanged event.

This code works for the new selected item

private void OnSelectedItemChanged(object sender, RoutedPropertyChangedEventArgs<object> e)
{
    var view = ItemContainerGenerator.ContainerFromItem(e.NewValue) as TreeViewItem;
    // ...
}

BUT if i want to get the TreeViewItem from an item saved in an ObservableCollection... it will not work.

EDIT: Ok, as i found out. The code above works only for the first level of items...

分享到QQ

分享到微博

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

需要登录才能够评论，你可以免费注册一个本站的账号。

终难遇 2024-11-03 00:24:48

编辑：这个问题的解决方案并不简单。可以使用视图模型（提供诸如 IsSelected、IsExpanded、IsEnabled 和 Parent 等基础知识的接口）来查找选定的树视图项。您可以像这样搜索 TreeViewItem：

if (treeViewItem.ItemContainerGenerator.Status != GeneratorStatus.ContainersGenerated)
{
    EventHandler eventHandler = null;

    eventHandler = delegate
    {
        treeViewItem.ItemContainerGenerator.StatusChanged -= eventHandler;
        // Call the search function recursive XYZ(tree, treeViewItem.ItemContainerGenerator.ContainerFromItem(nextLevelItem) as TreeViewItem);
    };

    // wait for the containers to be generated
    treeViewItem.ItemContainerGenerator.StatusChanged += eventHandler;
}
else
{
    // Call the search function recursive XYZ(tree, treeViewItem.ItemContainerGenerator.ContainerFromItem(nextLevelItem) as TreeViewItem);
}

EDIT: The solution for this problem isn't trivial. It is possible to find the selected treeview item by using a viewmodel (f.e. an interface which provides basics like: IsSelected, IsExpanded, IsEnabled and Parent). You can search the TreeViewItem like this:

if (treeViewItem.ItemContainerGenerator.Status != GeneratorStatus.ContainersGenerated)
{
    EventHandler eventHandler = null;

    eventHandler = delegate
    {
        treeViewItem.ItemContainerGenerator.StatusChanged -= eventHandler;
        // Call the search function recursive XYZ(tree, treeViewItem.ItemContainerGenerator.ContainerFromItem(nextLevelItem) as TreeViewItem);
    };

    // wait for the containers to be generated
    treeViewItem.ItemContainerGenerator.StatusChanged += eventHandler;
}
else
{
    // Call the search function recursive XYZ(tree, treeViewItem.ItemContainerGenerator.ContainerFromItem(nextLevelItem) as TreeViewItem);
}

回复收藏 0 原文

~没有更多了~