将 KeyUp 作为参数传递 WPF 命令绑定文本框 [英] Pass KeyUp as parameter WPF Command Binding Text Box

问题描述

我有一个文本框 KeyUp 事件触发器连接到 WPF 中的命令.我需要将按下的实际键作为命令参数传递.

I've a Text box KeyUp Event Trigger Wired up to a command in WPF. I need to pass the actual key that was pressed as a command parameter.

命令执行正常，但处理它的代码需要知道按下的实际键(记住这可能是一个输入键或任何不仅仅是一个字母的键，所以我无法从 TextBox.text 中获取它).

The command executes fine, but the code that handles it needs to know the actual key that was pressed (remember this could be an enter key or anything not just a letter, so I can't get it from the TextBox.text).

无法弄清楚如何做到这一点.XAML:

Can't figure out how to do this. XAML:

xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"

XAML:

<TextBox Height="23" Name="TextBoxSelectionSearch" Width="148" Tag="Enter Selection Name" Text="{Binding Path=SelectionEditorFilter.SelectionNameFilter,UpdateSourceTrigger=PropertyChanged}" >
       <i:Interaction.Triggers>
          <i:EventTrigger EventName="KeyUp">
             <i:InvokeCommandAction Command="{Binding SelectionEditorSelectionNameFilterKeyUpCommand}" />
          </i:EventTrigger>
       </i:Interaction.Triggers>
</TextBox>

推荐答案

我认为 InvokeCommandAction 无法实现，但您可以快速创建自己的 Behavior，大致如下所示:

I don't think that's possible with InvokeCommandAction but you can quickly create your own Behavior which could roughly look like this one:

public class KeyUpWithArgsBehavior : Behavior<UIElement>
{
    public ICommand KeyUpCommand
    {
        get { return (ICommand)GetValue(KeyUpCommandProperty); }
        set { SetValue(KeyUpCommandProperty, value); }
    }

    public static readonly DependencyProperty KeyUpCommandProperty =
        DependencyProperty.Register("KeyUpCommand", typeof(ICommand), typeof(KeyUpWithArgsBehavior), new UIPropertyMetadata(null));


    protected override void OnAttached()
    {
        AssociatedObject.KeyUp += new KeyEventHandler(AssociatedObjectKeyUp);
        base.OnAttached();
    }

    protected override void OnDetaching()
    {
        AssociatedObject.KeyUp -= new KeyEventHandler(AssociatedObjectKeyUp);
        base.OnDetaching();
    }

    private void AssociatedObjectKeyUp(object sender, KeyEventArgs e)
    {
        if (KeyUpCommand != null)
        {
            KeyUpCommand.Execute(e.Key);
        }
    }
}

然后将其附加到TextBox:

<TextBox Height="23" Name="TextBoxSelectionSearch" Width="148" Tag="Enter Selection Name" Text="{Binding Path=SelectionEditorFilter.SelectionNameFilter,UpdateSourceTrigger=PropertyChanged}" >
   <i:Interaction.Behaviors>
          <someNamespace:KeyUpWithArgsBehavior
                 KeyUpCommand="{Binding SelectionEditorSelectionNameFilterKeyUpCommand}" />
   </i:Interaction.Behaviors>
</TextBox>

只要这样，您就应该收到 Key 作为命令的参数.

With just that you should receive the Key as a parameter to the command.

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