WPF：如何防止窃取关键手势控制？ [英] WPF: How to prevent a control from stealing a key gesture?

问题描述

在我的WPF应用程序，我想输入的手势附加到命令，这样用户输入的手势全球可用在主窗口中，无论哪个控件具有焦点。

In my WPF application I would like to attach an input gesture to a command so that the input gesture is globally available in the main window, no matter which control has the focus.

在我的情况，我想不过来绑定 Key.PageDown 来的命令，只要某些控件接收焦点（如文本框或TreeView控件） ，这些控件接受的关键事件和命令不再触发。这些控件有没有具体的 CommandBindings 或 InputBindings 定义。

In my case I would like to bind Key.PageDown to a command, however, as soon as certain controls receive the focus (e.g. a TextBox or TreeView control), these controls receive the key events and the command is no longer triggered. These controls have no specific CommandBindings or InputBindings defined.

这是我如何定义我的输入姿势：

This is how I define my input gesture:

XAML：

<Window x:Class="Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Window1" Height="300" Width="300" >
    <StackPanel>
        <TreeView>
            <TreeViewItem Header="1">
                <TreeViewItem Header="1.1"></TreeViewItem>
                <TreeViewItem Header="1.2"></TreeViewItem>
            </TreeViewItem>
            <TreeViewItem Header="2" ></TreeViewItem>
        </TreeView>
        <TextBox />
        <Label Name="label1" />
    </StackPanel>
</Window>

代码：

Code:

using System;
using System.Windows;
using System.Windows.Input;

public static class Commands
{
    private static RoutedUICommand _myCommand;

    static Commands()
    {
        _myCommand = new RoutedUICommand("My Command",
            "My Command",
            typeof(Commands),
            new InputGestureCollection()
                {
                    new KeyGesture(Key.PageDown, ModifierKeys.None)
                });
    }

    public static ICommand MyCommand
    {
        get { return _myCommand; }
    }
}

public partial class Window1 : Window
{
    public Window1()
    {
        InitializeComponent();

        CommandBinding cb = new CommandBinding();
        cb.Command = Commands.MyCommand;
        cb.Executed += new ExecutedRoutedEventHandler(cb_Executed);
        cb.CanExecute += new CanExecuteRoutedEventHandler(cb_CanExecute);
        this.CommandBindings.Add(cb);
    }

    void cb_CanExecute(object sender, CanExecuteRoutedEventArgs e)
    {
        e.CanExecute = true;
    }

    void cb_Executed(object sender, ExecutedRoutedEventArgs e)
    {
        this.label1.Content = string.Format("My Command was executed {0}", DateTime.Now);
    }
}

我已经尝试捕获窗口的 PreviewKeyDown 事件并将其标记为处理这早已不是预期的效果。我还设置了可聚焦属性假。这有助于对TextBox控件，但不适合在TreeView（并具有不想要的效果，即在TextBox不再可以被编辑，所以它不是对我的溶液）。

I already tried catching the window's PreviewKeyDown event and marking it as handled This had not the desired effect. I also set the Focusable property to false. This helped for TextBox controls, but not for the TreeView (and has the unwanted effect, that the TextBox no longer can be edited so it is not a solution for me).

所以我的问题是我怎么能定义一个快捷键，在主窗口的工作原理无处不在？

So my question is how can I define a keyboard shortcut that works everywhere in the main window?

推荐答案

以下解决方法似乎有具有命令全球到窗口的期望的效果;但是，我仍然不知道是否有这样做的WPF没有更简单的方法：

The following workaround seems to have the desired effect of having the command global to the window; however, I still wonder whether there is no easier way to do this in WPF:

private void Window_PreviewKeyDown(object sender, KeyEventArgs e)
{
    foreach (InputBinding inputBinding in this.InputBindings)
    {
        KeyGesture keyGesture = inputBinding.Gesture as KeyGesture;
        if (keyGesture != null && keyGesture.Key == e.Key && keyGesture.Modifiers == Keyboard.Modifiers)
        {
            if (inputBinding.Command != null)
            {
                inputBinding.Command.Execute(0);
                e.Handled = true;
            }
        }
    }

    foreach (CommandBinding cb in this.CommandBindings)
    {
        RoutedCommand command = cb.Command as RoutedCommand;
        if (command != null)
        {
            foreach (InputGesture inputGesture in command.InputGestures)
            {
                KeyGesture keyGesture = inputGesture as KeyGesture;
                if (keyGesture != null && keyGesture.Key == e.Key && keyGesture.Modifiers == Keyboard.Modifiers)
                {
                    command.Execute(0, this);
                    e.Handled = true;
                }
            }
        }
    }
}

}

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