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所属分类:.NET技术
调用Win32 API(优先级最高,全局监听, 支持最小化失焦等情况)
那么,假如我要在一个WPF程序监听CTRL+5按键,首先在主窗口程序添加以下代码:
/// <summary> /// CTRL+5事件Id /// </summary> private const int Ctrl5KeyEventId = 9000; [DllImport("user32.dll")] public static extern bool RegisterHotKey(IntPtr hWnd, int id, uint fsModifiers, uint vk); [DllImport("user32.dll")] public static extern bool UnregisterHotKey(IntPtr hWnd, int id); protected override void OnSourceInitialized(EventArgs e) { base.OnSourceInitialized(e); var handle = new WindowInteropHelper(this).Handle; var source = HwndSource.FromHwnd(handle); source?.AddHook(HwndHook); //真正注册快捷键监听处理: 同时注册数字键和小键盘的CTRL+5 RegisterHotKey(handle, Ctrl5KeyEventId, (uint)ModifierKeys.Control, (uint)KeyInterop.VirtualKeyFromKey(Key.D5)); RegisterHotKey(handle, Ctrl5KeyEventId, (uint)ModifierKeys.Control, (uint)KeyInterop.VirtualKeyFromKey(Key.NumPad5)); } private IntPtr HwndHook(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled) { const int wmHotkey = 0x0312; switch (msg) { case wmHotkey: switch (wParam.ToInt32()) { case Ctrl5KeyEventId: Debug.WriteLine("Win32监听CTRL+5成功"); break; } break; } return IntPtr.Zero; } protected override void OnClosing(CancelEventArgs e) { base.OnClosing(e); var handle = new WindowInteropHelper(this).Handle; //关闭窗口后取消注册 UnregisterHotKey(handle, Ctrl5KeyEventId); }
监听WPF的KeyDown事件(不够清真,可选择,最小化失焦等情况监听失效)
public MainWindow() { InitializeComponent(); KeyDown += MainWindow_KeyDown; } private void MainWindow_KeyDown(object sender, KeyEventArgs e) { if (Keyboard.Modifiers == ModifierKeys.Control && (e.Key == Key.D5 || e.Key == Key.NumPad5)) { Debug.WriteLine("WPF的KeyDown事件监听CTRL+5成功"); ; e.Handled = true; } }
XAML绑定命令方式(WPF当然优先选中命令绑定啦,清真,最小化失焦等情况监听失效)
以下为Window主窗体的XAML代码
<Window.CommandBindings> <CommandBinding Command="{x:Static local:Commands.Ctrl5Command}" Executed="Ctrl5Command_OnExecuted"/> </Window.CommandBindings> <Window.InputBindings> <KeyBinding Modifiers="Control" Key="D5" Command="{x:Static local:Commands.Ctrl5Command}" /> <KeyBinding Modifiers="Control" Key="NumPad5" Command="{x:Static local:Commands.Ctrl5Command}" /> </Window.InputBindings>
在Window主窗体后台代码创建命令对应的Executed方法
private void Ctrl5Command_OnExecuted(object sender, ExecutedRoutedEventArgs e) { Debug.WriteLine("WPF的XAML绑定命令监听CTRL+5成功"); }
新增命令相关的静态类:
public static class Commands { public static ICommand Ctrl5Command { get; } = new RoutedCommand(); }
细节
三个监听方案的优先级
其中Win32 > XAML绑定命令 = KeyDown事件,假如同时监听的话,其中会只处理高优先级的,以上面的例子,假如
我同时监听三个,只会处理win32的
Win32监听CTRL+5成功
全局监听问题
其中win32支持全局监听键盘,也就是窗口在失焦情况下,例如最小化,也能监听得到,其中XAML绑定命令
和KeyDown事件
不支持失焦情况,最小化等情况也就监听不到了,因此,要按业务选择方案