c# - 从任何进程获取 key

Question

我在网上看到了很多解决方案，但没有一个完全符合我的要求。当我的应用程序在后台运行时，在给定进程(不是我的控制台应用程序)中按下任何键的最佳/最简单方法是什么。我不需要修饰符或任何东西。

Answer 1

如果您不特别关心按键被按下的过程，最简单的方法是调用 GetAsyncKeyState .它相当有限，因为它不会挂接键盘并且需要您连续调用它。我认为最好的方法是挂接键盘。

使用 SetWindowsHookEx您实际上可以明确指定与 Hook 过程相关联的线程的标识符，以便您可以 Hook 特定进程的键(请参阅 dwThreadId)。

这是一个你可以使用的类(最初是在 Micrsoft 博客上找到的，但我现在似乎找不到作者的名字!)

public delegate IntPtr KeyboardProcess(int nCode, IntPtr wParam, IntPtr lParam);

public sealed class KeyboardHook
{
    public static event EventHandler<KeyPressedEventArgs> KeyPressed;
    private const int WH_KEYBOARD = 13;
    private const int WM_KEYDOWN = 0x0100;
    private static KeyboardProcess keyboardProc = HookCallback;
    private static IntPtr hookID = IntPtr.Zero;

    public static void CreateHook()
    {
        hookID = SetHook(keyboardProc);
    }

    public static void DisposeHook()
    {
        UnhookWindowsHookEx(hookID);
    }

    private static IntPtr SetHook(KeyboardProcess keyboardProc)
    {
        using (Process currentProcess = Process.GetCurrentProcess())
        using (ProcessModule currentProcessModule = currentProcess.MainModule)
        {
            return SetWindowsHookEx(WH_KEYBOARD, keyboardProc, GetModuleHandle(currentProcessModule.ModuleName), 0);
        }
    }

    private static IntPtr HookCallback(int nCode, IntPtr wParam, IntPtr lParam)
    {
        if (nCode >= 0 && wParam == (IntPtr)WM_KEYDOWN)
        {
            int vkCode = Marshal.ReadInt32(lParam);

            if (KeyPressed != null)
                KeyPressed(null, new KeyPressedEventArgs((Keys)vkCode));
        }
        return CallNextHookEx(hookID, nCode, wParam, lParam);
    }

    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    private static extern IntPtr SetWindowsHookEx(int idHook, KeyboardProcess lpfn, IntPtr hMod, uint dwThreadId);

    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    private static extern IntPtr CallNextHookEx(IntPtr hhk, int nCode, IntPtr wParam, IntPtr lParam);

    [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    private static extern IntPtr GetModuleHandle(string lpModuleName);

    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    private static extern bool UnhookWindowsHookEx(IntPtr hhk);

}

public class KeyPressedEventArgs : EventArgs
{
    public Keys KeyCode { get; set; }
    public KeyPressedEventArgs(Keys Key)
    {
        KeyCode = Key;
    }
}

通过控制台应用程序实现:

class Program
{
    static void Main(string[] args)
    {
        KeyboardHook.CreateHook();
        KeyboardHook.KeyPressed += KeyboardHook_KeyPressed;
        Application.Run();
        KeyboardHook.DisposeHook();
    }

    static void KeyboardHook_KeyPressed(object sender, KeyPressedEventArgs e)
    {
        Console.WriteLine(e.KeyCode.ToString());
    }
}