WPF TreeView 绑定命令并传递单击的元素

Question

如何将命令绑定到 TreeView 中的元素。我有 MainWindowViewModel 和 TreeViewCommand，我试图在元素周围添加按钮，但不会调用命令。有没有其他方法可以调用命令并传递单击的元素？

<TreeView x:Name="MainTreeView" HorizontalAlignment="Stretch" Margin="10" VerticalAlignment="Stretch" ItemsSource="{Binding Departments}">
        <TreeView.ItemTemplate>
            <HierarchicalDataTemplate ItemsSource="{Binding Positions}" DataType="{x:Type VM:Department}">
                <Button Command="{Binding TreeViewCommand}" CommandParameter="{Binding DepartmentName}" BorderThickness="0" Style="{StaticResource {x:Static ToolBar.ButtonStyleKey}}" >
                    <Label Content="{Binding DepartmentName}"/>
                </Button>
                <HierarchicalDataTemplate.ItemTemplate>
                    <HierarchicalDataTemplate ItemsSource="{Binding Employees}" DataType="{x:Type VM:Position}">
                        <Button BorderThickness="0" Style="{StaticResource {x:Static ToolBar.ButtonStyleKey}}" >
                        <Label Content="{Binding PositionName}"/>
                        </Button>
                        <HierarchicalDataTemplate.ItemTemplate>
                            <DataTemplate DataType="{x:Type VM:Employee}">
                                <Button BorderThickness="0" Style="{StaticResource {x:Static ToolBar.ButtonStyleKey}}" >
                                <Label Content="{Binding EmployeeName}"/>
                                </Button>
                            </DataTemplate>
                        </HierarchicalDataTemplate.ItemTemplate>
                    </HierarchicalDataTemplate>
                </HierarchicalDataTemplate.ItemTemplate>
            </HierarchicalDataTemplate>
        </TreeView.ItemTemplate>
    </TreeView>

我的 MainWindowViewMode 是

public class MainWindowViewModel : ViewModelBase
{

    private List<Department> departments;
    public MyICommand<string> TreeViewCommand { get; private set; }

    public MainWindowViewModel()
    {
        TreeViewCommand = new MyICommand<string>(myTreeViewCommand);
        Departments = new List<Department>()
        {
            new Department("DotNet"),
            new Department("PHP")
        };
    }

    public List<Department> Departments
    {
        get
        {
            return departments;
        }
        set
        {
            departments = value;
            OnPropertyChanged("Departments");
        }
    }

    public void myTreeViewCommand(string par) 
    {
        Console.ReadKey();
    }
}

Answer 1

由于您的 TreeViewCommand 在您的 TreeView 范围内，它具有 Departments 对象，因为它是 DataContext，因此它找不到命令。您应该显式定义定义 TreeViewCommand 的 DataContext。执行以下操作：

<!-- Note the ElementName and Path=DataContext. -->
<Button Command="{Binding ElementName=MainTreeView, Path=DataContext.TreeViewCommand}" CommandParameter="{Binding DepartmentName}" BorderThickness="0" Style="{StaticResource {x:Static ToolBar.ButtonStyleKey}}" >
    <Label Content="{Binding DepartmentName}"/>
</Button>

XAML 所有节点：

<TreeView x:Name="MainTreeView" HorizontalAlignment="Stretch" Margin="10" VerticalAlignment="Stretch" ItemsSource="{Binding Departments}">
    <TreeView.ItemTemplate>
        <HierarchicalDataTemplate ItemsSource="{Binding Positions}">
            <Button Command="{Binding ElementName=MainTreeView, Path=DataContext.TreeViewCommand}" CommandParameter="{Binding DepartmentName}" BorderThickness="0" Style="{StaticResource {x:Static ToolBar.ButtonStyleKey}}" >
                <Label Content="{Binding DepartmentName}"/>
            </Button>
            <HierarchicalDataTemplate.ItemTemplate>
                <HierarchicalDataTemplate ItemsSource="{Binding Employees}">
                    <Button Command="{Binding ElementName=MainTreeView, Path=DataContext.TreeViewCommand}" CommandParameter="{Binding PositionName}" BorderThickness="0" Style="{StaticResource {x:Static ToolBar.ButtonStyleKey}}" >
                        <Label Content="{Binding PositionName}"/>
                    </Button>
                    <HierarchicalDataTemplate.ItemTemplate>
                        <DataTemplate>
                            <Button Command="{Binding ElementName=MainTreeView, Path=DataContext.TreeViewCommand}" CommandParameter="{Binding EmployeeName}" BorderThickness="0" Style="{StaticResource {x:Static ToolBar.ButtonStyleKey}}" >
                                <Label Content="{Binding EmployeeName}"/>
                            </Button>
                        </DataTemplate>
                    </HierarchicalDataTemplate.ItemTemplate>
                </HierarchicalDataTemplate>
            </HierarchicalDataTemplate.ItemTemplate>
        </HierarchicalDataTemplate>
    </TreeView.ItemTemplate>
</TreeView>

注意！如果您最终想要传递对象而不是字符串（节点名称），则必须为每个按钮定义 ICommands。

WPF TreeView 绑定命令并传递单击的元素

WPF TreeView binding command and passing which element was clicked on

.net

c#

wpf

treeview