如何在WPF中将属性绑定到TreeView中的选定节点

Question

如何在MVVM中将自定义属性绑定到所选节点的IsSelected属性，我已经在运行时将节点加载到树形视图中。

- Tanya

Answer 1

以下是一个小例子：

public abstract class ViewModel : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    protected void OnPropertyChanged(string propertyName)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}

public class MyViewModel : ViewModel
{
    public ObservableCollection<Item> Items
    {
        get
        {
            return new ObservableCollection<Item>()
            {
                new Item() {DisplayValue = "Item1", IsSelected = false, Sample = "Sample: I am Item1"},
                new Item() {DisplayValue = "Item2", IsSelected = true, Sample = "Sample: I am Item2"},
                new Item() {DisplayValue = "Item3", IsSelected = false, Sample = "Sample: I am Item3"}
            };
        }
    }
}

public class Item : ViewModel
{
    public string DisplayValue { get; set; }

    private bool _isSelected = false;

    public bool IsSelected
    {
        get
        {
            return _isSelected;
        }
        set
        {
            _isSelected = value;
            OnPropertyChanged("IsSelected");
        }
    }

    private string _sample;

    public string Sample
    {
        get
        {
            return _sample;
        }
        set
        {
            _sample = value;
            OnPropertyChanged("Sample");
        }
    }
}

XAML:

<Window x:Class="WpfApplication93.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:WpfApplication93"
        Title="MainWindow" Height="350" Width="525">
  <Grid>
    <Grid.DataContext>
      <local:MyViewModel></local:MyViewModel>
    </Grid.DataContext>

    <StackPanel>
      <TreeView x:Name="myTreeView" ItemsSource="{Binding Items}">
        <TreeView.ItemContainerStyle>
          <Style TargetType="{x:Type TreeViewItem}">
            <Setter Property="IsSelected" Value="{Binding IsSelected}"></Setter>
            <Setter Property="Template">
              <Setter.Value>
                <ControlTemplate TargetType="TreeViewItem">
                  <TextBlock Text="{Binding DisplayValue}"></TextBlock>
                </ControlTemplate>
              </Setter.Value>
            </Setter>

            <Style.Triggers>
              <Trigger Property="IsSelected" Value="True">
                <!-- if you want to customize the appearance of a selected element do it here -->
                <Setter Property="FontWeight" Value="Bold" />
              </Trigger>
            </Style.Triggers>
          </Style>
        </TreeView.ItemContainerStyle>
      </TreeView>

      <Label Content="{Binding ElementName=myTreeView, Path=SelectedItem.Sample}"></Label>
    </StackPanel>
  </Grid>
</Window>

- SvenG

---

<TreeView.ItemContainerStyle> <Style TargetType="{x:Type TreeViewItem}"> <Setter Property="IsSelected" Value="{Binding IsSelected, Mode=TwoWay}" /> </Style> </TreeView.ItemContainerStyle>我使用了上述代码，并在IsSelected属性上设置了断点，但它没有起作用。 - Tanya

请查看输出窗口。您是否发现任何绑定错误？Getter是否正常工作，即当您将一个Treeviewitem设置为IsSelected=true时，它是否在视图中被选中？ - SvenG

当我在树形视图中选择一个节点时，我想执行一些操作。 - Tanya

你的示例代码可以将所选项目加粗，但无法处理selectedItemChanged事件。 - Tanya

让我们在聊天中继续这个讨论：http://chat.stackoverflow.com/rooms/6571/discussion-between-sveng-and-tanya - SvenG