视图中的 MouseDoubleClick 事件

Question

当我使用 mvvm 和 Prism 2 时，如何在视图中绑定 wpfdatagrid 的 MouseDoubleClick 事件。

Answer 1

我更喜欢添加 MouseDoubleClickBehaviour，然后您可以将其附加到任何控件，该控件将绑定到您的 ViewModel。从视图的代码隐藏调用命令会创建我不喜欢的直接依赖关系。

public static class MouseDoubleClickBehaviour
{
    public static readonly DependencyProperty CommandProperty =
        DependencyProperty.RegisterAttached("Command", typeof(ICommand), typeof(MouseDoubleClickBehaviour), new UIPropertyMetadata(null, OnCommandChanged));

    public static readonly DependencyProperty CommandParameterProperty =
        DependencyProperty.RegisterAttached("CommandParameter", typeof(object), typeof(MouseDoubleClickBehaviour), new UIPropertyMetadata(null));

    public static ICommand GetCommand(DependencyObject obj)
    {
        return (ICommand)obj.GetValue(CommandProperty);
    }

    public static void SetCommand(DependencyObject obj, ICommand value)
    {
        obj.SetValue(CommandProperty, value);
    }

    public static object GetCommandParameter(DependencyObject obj)
    {
        return obj.GetValue(CommandParameterProperty);
    }

    public static void SetCommandParameter(DependencyObject obj, object value)
    {
        obj.SetValue(CommandParameterProperty, value);
    }

    private static void OnCommandChanged(DependencyObject target, DependencyPropertyChangedEventArgs args)
    {
        var grid = target as Selector;

        ////Selector selector = target as Selector;
        if (grid == null)
        {
            return;
        }

        grid.MouseDoubleClick += (a, b) => GetCommand(grid).Execute(grid.SelectedItem);
    }
}

然后你可以在 XAML 中执行此操作

<ListView ...
     behaviours:MouseDoubleClickBehaviour.Command="{Binding Path=ItemSelectedCommand}"
     behaviours:MouseDoubleClickBehaviour.CommandParameter="{Binding ElementName=txtValue, Path=Text}"
 .../>

Answer 2

在 View 的代码隐藏中侦听 MouseDoubleClick 事件，并在 ViewModel 上调用适当的方法：

public class MyView : UserControl 
{
    ...

    private MyViewModel ViewModel { get { return DataContext as MyViewModel; } }

    private void ListView_MouseDoubleClick(object sender, MouseButtonEventArgs e)
    {
        ViewModel.OpenSelectedItem();
    }