如何在Caliburn.Micro中绑定关键手势？

Question

如何让Caliburn.Micro将关键手势映射到我的ViewModel上的动作方法？

例如,我想实现一个选项卡式界面,我希望我的ShellViewModel有一个NewTab方法,用户应该可以通过按键盘上的Ctrl + T来调用它.

我知道完整的Caliburn框架支持手势,但我怎么能用Caliburn.Micro做到这一点？是否有某种方法可以将动作绑定到RoutedCommand(因为RoutedCommands已经支持输入手势)？或者其他一些获得手势支持的方式？

Answer 1

我修改了示例以启用对全局键绑定的支持.您只需将以下代码添加到视图中:

<i:Interaction.Triggers>
        <common:InputBindingTrigger>
            <common:InputBindingTrigger.InputBinding>
                <KeyBinding Modifiers="Control" Key="D"/>
            </common:InputBindingTrigger.InputBinding>
            <cl:ActionMessage MethodName="DoTheMagic"/>
        </common:InputBindingTrigger>
    </i:Interaction.Triggers>

每当按下Ctr + D时,方法DoTheMagic将被执行.这是修改后的InputBindingTrigger代码:

public class InputBindingTrigger : TriggerBase<FrameworkElement>, ICommand
  {
    public static readonly DependencyProperty InputBindingProperty =
      DependencyProperty.Register("InputBinding", typeof (InputBinding)
        , typeof (InputBindingTrigger)
        , new UIPropertyMetadata(null));

    public InputBinding InputBinding
    {
      get { return (InputBinding) GetValue(InputBindingProperty); }
      set { SetValue(InputBindingProperty, value); }
    }

    public event EventHandler CanExecuteChanged = delegate { };

    public bool CanExecute(object parameter)
    {
      // action is anyway blocked by Caliburn at the invoke level
      return true;
    }

    public void Execute(object parameter)
    {
      InvokeActions(parameter);
    }

    protected override void OnAttached()
    {
      if (InputBinding != null)
      {
        InputBinding.Command = this;        
        AssociatedObject.Loaded += delegate {
          var window = GetWindow(AssociatedObject);
          window.InputBindings.Add(InputBinding);
        };
      }
      base.OnAttached();
    }

    private Window GetWindow(FrameworkElement frameworkElement)
    {
      if (frameworkElement is Window)
        return frameworkElement as Window;

      var parent = frameworkElement.Parent as FrameworkElement;      
      Debug.Assert(parent != null);

      return GetWindow(parent);
    }
  }

Answer 2

Caliburn.Micro的Actions机制建立在System.Windows.Interactivity之上.因此,您可以创建基于TriggerBase的自定义触发器来执行任何操作,包括全局键盘手势.然后,只需将ActionMessage插入触发器和中提琴!

Answer 3

您可以通过从System.Windows.Interactivity.TriggerBase派生来实现.这是一个例子.