我正在尝试在 WinUI3 桌面应用程序中动态生成树视图。它可以生成树，但默认情况下所有节点都未选中。我的应用程序需要记住选择并复制以前的状态。
从技术上讲，我可以从中读取选择状态TreeView.SelectedNodes。但是我无法找到从代码中选择节点的方法。
我在网上找到了几篇关于 WPF 或 UWP 的相关文章，但没有针对 WinUI3。
环境
- WinUI3桌面
- Windows 应用 SDK 1.0.0
- MvvmGen 1.1.2
目标
- 在启动时选择树中的一些项目。
- 从 ViewModel 中读取选择的状态。
问题
- 无法将视图中的 IsSelected 属性绑定到
ListViewItem.IsSelected。
代码
MainWindow.xaml
<Window
x:Class="WinUITreeViewTest.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:WinUITreeViewTest"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d">
<StackPanel DataContext="MainWindowViewModel">
<TreeView Name="MyItemView" SelectionMode="Multiple" ItemsSource="{Binding MyItems}">
<TreeView.ItemTemplate>
<DataTemplate x:DataType="local:MyItem">
<TreeViewItem ItemsSource="{Binding Children}" Content="{Binding Name}" IsExpanded="{Binding IsExpanded}" IsSelected="{Binding IsSelected}"/>
</DataTemplate>
</TreeView.ItemTemplate>
</TreeView>
</StackPanel>
</Window>
在TreeViewItem节点中，它旨在绑定MyItem.IsSelected到TreeViewItem.IsSelcted. 是行不通的。
MainWindow.xaml.cs
public sealed partial class MainWindow : Window
{
public MainWindow()
{
this.InitializeComponent();
ViewModel = new MainWindowViewModel();
MyItemView.DataContext = ViewModel;
ObservableCollection<MyItem> root = new ObservableCollection<MyItem>();
MyItem item1 = new MyItem() { Name = "Item1", IsExpanded=true };
root.Add(item1);
item1.Children.Add(new MyItem() { Name = "Item1.1" });
item1.Children.Add(new MyItem() { Name = "Item1.2" });
item1.Children.Add(new MyItem() { Name = "Item1.3", IsSelected=true });
MyItem item2 = new MyItem() { Name = "Item2", IsExpanded = true };
root.Add(item2);
item2.Children.Add(new MyItem() { Name = "Item2.1" });
item2.Children.Add(new MyItem() { Name = "Item2.2" });
item2.Children.Add(new MyItem() { Name = "Item2.3" });
MyItem item3 = new MyItem() { Name = "Item3", IsExpanded = true };
root.Add(item3);
item3.Children.Add(new MyItem() { Name = "Item3.1" });
item3.Children.Add(new MyItem() { Name = "Item3.2" });
item3.Children.Add(new MyItem() { Name = "Item3.3" });
ViewModel.MyItems = root;
}
MainWindowViewModel ViewModel;
}
MainWindowViewModel.cs
[ViewModel]
public partial class MainWindowViewModel
{
[Property]
ObservableCollection<MyItem> myItems;
}
[ViewModel]
public partial class MyItem
{
[Property]
private string name;
public override string ToString() => Name;
[Property]
private bool? isSelected;
[Property]
private bool isExpanded;
[Property]
private ObservableCollection<MyItem> children = new ObservableCollection<MyItem>();
}
MvvmGen 像这样自动为 MVVM 生成相应的属性。
public bool? IsSelected
{
get => isSelected;
set
{
if (isSelected != value)
{
isSelected = value;
OnPropertyChanged("IsSelected");
}
}
}
参考：https ://github.com/hayashida-katsutoshi/WinUITreeViewTest