Question

我在Canvas中有一个Control，我希望能够使用箭头键移动它。为了解决问题，我创建了以下类，它可以实现我的目标。

<Window x:Class="DiagramDesigner.CanvasControlArrowKeyTest"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
        Title="CanvasControlArrowKeyTest" Height="300" Width="300">
    <Canvas>
        <Canvas.InputBindings>
            <KeyBinding Key="Down" Command="MoveDown" />
            <KeyBinding Key="Up" Command="MoveUp" />
            <KeyBinding Key="Right" Command="MoveRight" />
            <KeyBinding Key="Left" Command="MoveLeft" />
        </Canvas.InputBindings>
        <Button>
            <Button.CommandBindings>
                <CommandBinding Command="MoveDown" Executed="MoveDown_Executed" />
                <CommandBinding Command="MoveUp" Executed="MoveUp_Executed" />
                <CommandBinding Command="MoveLeft" Executed="MoveLeft_Executed" />
                <CommandBinding Command="MoveRight" Executed="MoveRight_Executed" />
            </Button.CommandBindings>
        </Button>
    </Canvas>
</Window>

以下是代码隐藏的片段：

private void MoveDown_Executed(object sender, ExecutedRoutedEventArgs e)
{
    var uiElement = (UIElement)sender;
    double value = Canvas.GetTop(uiElement);
    value = Double.IsNaN(value) ? 0 : value;
    value++;
    Canvas.SetTop(uiElement, value < 0 ? 0 : value);
}

这一切都很好，但我真正想要的是一堆具有这种能力的按钮，而不仅仅是那个。如何确保每个按钮都有这些CommandBindings？如果有比使用CommandBindings更简单的方法，可能是什么？

更新：根据请求，这是另一种似乎不起作用的方法：

<Window x:Class="DiagramDesigner.CanvasControlArrowKeyTest"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
        Title="CanvasControlArrowKeyTest" Height="300" Width="300">
    <Window.CommandBindings>
        <CommandBinding Command="MoveDown" Executed="MoveDown_Executed" />
        <CommandBinding Command="MoveUp" Executed="MoveUp_Executed" />
        <CommandBinding Command="MoveLeft" Executed="MoveLeft_Executed" />
        <CommandBinding Command="MoveRight" Executed="MoveRight_Executed" />
    </Window.CommandBindings>
    <Window.InputBindings>
        <KeyBinding Key="Down" Command="MoveDown" />
        <KeyBinding Key="Up" Command="MoveUp" />
        <KeyBinding Key="Right" Command="MoveRight" />
        <KeyBinding Key="Left" Command="MoveLeft" />
    </Window.InputBindings>
    <Canvas >
        <Button Width="50" Height="50" />
    </Canvas>
</Window>

C＃

private void MoveDown_Executed(object sender, ExecutedRoutedEventArgs e)
{
    var uiElement = (UIElement)e.OriginalSource; // Still doesn't point to the Button
    double value = Canvas.GetTop(uiElement);
    value = Double.IsNaN(value) ? 0 : value;
    value++;
    Canvas.SetTop(uiElement, value < 0 ? 0 : value);
}

更新：我放弃了这种方法。我最终使用different solution来解决问题，不使用命令。

Answer 1

您应该查看路由事件处理程序：http://msdn.microsoft.com/en-us/library/ms742806.aspx

上面的链接有一个如何做你要问的例子。

<Border Height="50" Width="300" BorderBrush="Gray" BorderThickness="1">
  <StackPanel Background="LightGray" Orientation="Horizontal" Button.Click="CommonClickHandler">
    <Button Name="YesButton" Width="Auto" >Yes</Button>
    <Button Name="NoButton" Width="Auto" >No</Button>
    <Button Name="CancelButton" Width="Auto" >Cancel</Button>
  </StackPanel>
</Border>

代码

private void CommonClickHandler(object sender, RoutedEventArgs e)
{
  FrameworkElement feSource = e.Source as FrameworkElement;
  switch (feSource.Name)
  {
    case "YesButton":
      // do something here ...
      break;
    case "NoButton":
      // do something ...
      break;
    case "CancelButton":
      // do something ...
      break;
  }
  e.Handled=true;
}

Answer 2

如果在顶级对象（在本例中为Window）中创建命令绑定，则可以为窗口的任何子项重用它们。

<Window x:Class="TesterApp.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:data="clr-namespace:TesterApp"
        x:Name="TheMainWindow"
        Title="MainWindow" Height="350" Width="525">
    <Window.Resources>
    </Window.Resources>
    <Window.InputBindings>
        <KeyBinding Key="A" Command="MoveDown" />
    </Window.InputBindings>
    <Window.CommandBindings>
        <CommandBinding Command="MoveDown" Executed="MoveDown_Executed" />
    </Window.CommandBindings>
    <Grid>
        <Button Height="30" Width="80" Content="Click" Command="MoveDown" />
    </Grid>
</Window>

将同一组命令附加/绑定到多个控件

2 个答案: