實現鍵盤快捷鍵

Question

我目前使用的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，如果我有好幾個快捷鍵，這就會變得混亂。

有更好的實施嗎？

Answer 1

你應該看看如何實現<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<Button>就變成了：

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

的SettingsCanExecute方法確定按鈕時啓用，並且SettingsExecuted方法被調用時，該按鈕被按下或按鍵組合被擊中。

然後您不需要KeyDown處理程序。

關於開啓代碼有full tutorial。

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

Answer 2

爲他人記錄這個答案，因爲有一種很簡單的方法來做到這一點很少被引用，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。作爲命令，傳入實現ICommand的任意命令類。對於執行方法，只需實現你需要的任何邏輯。在我下面的例子中，我的WindowCommand類接受一個委託，它將在調用時執行。當我構造新的WindowCommand以使用我的綁定進行傳入時，我只需在我的初始化程序中指示我希望WindowCommand執行的方法。

您可以使用此模式來創建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，該類需要執行委託來觸發設置的任何方法。

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."); 
     } 
    } 
}