如何在WPF中创建无法选择的TreeViewItem [英] How to create unselectable TreeViewItem in WPF

问题描述

我正在绑定TreeView。我的原因是无法选择Treeview级别0。当我单击级别0 treeviewitem时，当前项必须折叠并且必须选择第一个子项。

I'm binding TreeView. My reason is treeview level 0 is unselectable. When i click level 0 treeviewitem, current item must be collapse and first child item must be selected.

├ Item 1   //<- level 0. this item must be unselectable
├─ Child Item 11 //<- level 1
├─ Child Item 12
├ Item 2   //<- level 0. When i click this item, that is automatically collapse
├─ Child Item 21
├─ Child Item 22

如何使用样式？

推荐答案

我会在我的视图模型中做到这一点。级别0项的视图模型将具有：

I'd do it in my view model. The view model for level 0 items would have:

public bool IsSelected
{
    get { return false; }
    set
    {
        // error checking is omitted
        Children[0].IsSelected = value;

        // let WPF know that IsSelected may have changed from what it's expecting
        this.Dispatcher.BeginInvoke((ThreadStart)delegate
        {
            this.OnPropertyChanged(() => this.IsSelected);
        });
    }
}

您的XAML如下所示：

Your XAML would look like:

<TreeView>
    <TreeView.ItemContainerStyle>
        <Style TargetType="TreeViewItem">
            <Setter Property="IsSelected" Value="{Binding IsSelected}"/>
        </Style>
    </TreeView.ItemContainerStyle>
</TreeView>

现在，每当用户单击一级项目时，VM都会拒绝选择，而改为选择它的第一个子项。

Now whenever the user clicks on a level-one item, the VM will refuse to be selected and instead select its first child item.

您可以使用完全相同的技术来处理有关折叠级别的要求。

You can use exactly the same technique to handle your requirements around collapsing levels.

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