實現鍵盤快捷鍵

Question

我目前使用onKeyDown事件和if/else語句來創建鍵盤快捷鍵：

if ((Keyboard.Modifiers & ModifierKeys.Shift) == ModifierKeys.Shift && e.Key == Key.Tab) {

} else if (e.Key == Key.Tab) {

} ...

但是，如果我有更多的鍵盤快捷鍵，這會變得混亂。

有更好的實施嗎？

Answer 1

您應該看一下實現<CommandBindings>和<InputBindings> ：

<Window.CommandBindings>
    <CommandBinding Command="Settings" CanExecute="SettingsCanExecute" Executed="SettingsExecuted" />
</Window.CommandBindings>

<Window.InputBindings>
    <KeyBinding Command="Settings" Key="S" Modifiers="Alt" />
</Window.InputBindings>

你的<Button>然后變成：

<Button Height="50" Width="50" Margin="50,5,0,0" Command="Settings" />

SettingsCanExecute方法確定何時啟用該按鈕，並在按下按鈕或敲擊組合鍵時調用SettingsExecuted方法。

然后，您不需要KeyDown處理程序。

有關Switch On The Code的完整教程 。

有關CommandBindings和InputBindings的更多信息可以在MSDN上找到。

Answer 2

為其他人記錄這個答案，因為有一個很簡單的方法來做這個很少被引用，並且根本不需要觸摸XAML。

要鏈接鍵盤快捷鍵，只需在Window構造函數中添加一個新的KeyBinding到InputBindings集合。 作為命令，傳入實現ICommand的任意命令類。 對於execute方法，只需實現您需要的任何邏輯。 在下面的示例中，我的WindowCommand類接受一個委托，它將在每次調用時執行。 當我構造新的WindowCommand以傳入我的綁定時，我只是在我的初始化程序中指出我希望WindowCommand執行的方法。

您可以使用此模式來提供自己的快捷鍵盤快捷鍵。

public YourWindow() //inside any WPF Window constructor
{
   ...
   //add this one statement to bind a new keyboard command shortcut
   InputBindings.Add(new KeyBinding( //add a new key-binding, and pass in your command object instance which contains the Execute method which WPF will execute
      new WindowCommand(this)
      {
         ExecuteDelegate = TogglePause //REPLACE TogglePause with your method delegate
      }, new KeyGesture(Key.P, ModifierKeys.Control)));
   ...
}

創建一個簡單的WindowCommand類，它接受一個執行委托來觸發它上面的任何方法集。

public class WindowCommand : ICommand
{
    private MainWindow _window;

    //Set this delegate when you initialize a new object. This is the method the command will execute. You can also change this delegate type if you need to.
    public Action ExecuteDelegate { get; set; }

    //You don't have to add a parameter that takes a constructor. I've just added one in case I need access to the window directly.
    public WindowCommand(MainWindow window)
    {
        _window = window;
    }

    //always called before executing the command, mine just always returns true
    public bool CanExecute(object parameter)
    {
        return true; //mine always returns true, yours can use a new CanExecute delegate, or add custom logic to this method instead.
    }

    public event EventHandler CanExecuteChanged; //i'm not using this, but it's required by the interface

    //the important method that executes the actual command logic
    public void Execute(object parameter)
    {
        if (ExecuteDelegate != null) //let's make sure the delegate was set
        {
            ExecuteDelegate();
        }
        else
        {
            throw new InvalidOperationException("ExecuteDelegate has not been set. There is no method to execute for this command.");
        }
    }
}