在 Winforms 中捕获 WinKey+D 键序列

Question

我试图让我的应用程序始终显示在桌面级别。这意味着我的应用程序需要忽略 LWin+D 或 RWin+D 等键序列。我试图让它以这种方式工作：

protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
{
    if (prefixSeen)
    {
        if (keyData == Keys.D)
        {
            MessageBox.Show("Got it!");
        }
        prefixSeen = false;
        return true;
    }
    if (keyData == Keys.LWin)
    {
        prefixSeen = true;
        return true;
    }
    return base.ProcessCmdKey(ref msg, keyData);
}

但它只捕获 RWin/LWin 按钮，没有 D 按钮。

我也曾尝试创建自己的邮件过滤器，但我迷失了方向。所有这些 messages 和按位：

    public class KeystrokMessageFilter : System.Windows.Forms.IMessageFilter
    {
        public KeystrokMessageFilter() { }

        public bool PreFilterMessage(ref Message m)
        {
            if ((m.Msg == 256 /*0x0100*/))
            {
                switch (((int)m.WParam) | ((int)Control.ModifierKeys))
                {
                    case (int)(Keys.Control | Keys.Alt | Keys.K):
                        MessageBox.Show("You pressed ctrl + alt + k");
                        break;
                    case (int)(Keys.Control | Keys.C): MessageBox.Show("ctrl+c");
                        break;
                    case (int)(Keys.Control | Keys.V): MessageBox.Show("ctrl+v");
                        break;
                    case (int)Keys.Up: MessageBox.Show("You pressed up");
                        break;
                }
            }
            return false;
        }
}

Application.AddMessageFilter(keyStrokeMessageFilter);

那么，我该如何申请 catch/ignore R/LWin+D？

Answer 1

尝试 How to detect when a windows form is being minimized? 中的解决方案，在事件触发之前捕获并处理它；它应该允许您忽略它。

Answer 2

此代码注册一个低级键盘钩子，并在按住 windows 键时侦听 D 按键。如果检测到这一点，挂钩会简单地忽略按键。否则，它会转发按键。

using System;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Windows.Forms;

namespace KbHook
{
    public static class Program
    {
        const int HC_ACTION = 0;
        const int WH_KEYBOARD_LL = 13;
        const int WM_KEYDOWN = 0x0100;
        static IntPtr HookHandle = IntPtr.Zero;
        static Form1 Form1;

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

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

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

        [STAThread]
        static void Main()
        {
            try
            {
                using (var proc = Process.GetCurrentProcess())
                    using (var curModule = proc.MainModule)
                    {
                        var moduleHandle = GetModuleHandle(curModule.ModuleName);
                        HookHandle = SetWindowsHookEx(WH_KEYBOARD_LL, IgnoreWin_D, moduleHandle, 0);
                    }

                Form1 = new Form1();
                Application.Run(Form1);
            }
            finally
            {
                UnhookWindowsHookEx(HookHandle);
            }
        }

        [DllImport("user32.dll")]
        static extern short GetAsyncKeyState(Keys vKey);

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

        static IntPtr IgnoreWin_D(int nCode, IntPtr wParam, IntPtr lParam)
        {
            if (nCode == HC_ACTION
                && IsWin_D(wParam, lParam))
                return (IntPtr) 1; //just ignore the key press

            return CallNextHookEx(HookHandle, nCode, wParam, lParam);
        }

        static bool IsWin_D(IntPtr wParam, IntPtr lParam)
        {
            if ((int) wParam != WM_KEYDOWN)
                return false;

            var keyInfo = (KbHookParam) Marshal.PtrToStructure(lParam, typeof (KbHookParam));
            if (keyInfo.VkCode != (int) Keys.D) return false;
            return GetAsyncKeyState(Keys.LWin) < 0
                   || GetAsyncKeyState(Keys.RWin) < 0;
        }

        delegate IntPtr KbHook(int nCode, IntPtr wParam, [In] IntPtr lParam);

        [StructLayout(LayoutKind.Sequential)]
        struct KbHookParam
        {
            public readonly int VkCode;
            public readonly int ScanCode;
            public readonly int Flags;
            public readonly int Time;
            public readonly IntPtr Extra;
        }
    }
}

另见 How to hook Win + Tab using LowLevelKeyboardHook

Answer 3

我知道这个问题太老了。但是，嘿，我最近不得不开发一个应用程序，它将像小部件一样保留在桌面上（为我公司的年度倒计时应用程序 bash）。

即使通过 windows 低级键盘钩子按下 WinKey+D 或 WinKey+M，我也设法让 window 留在后台（桌面 winform）。我使用了 dss539 的代码并对其进行了改进，以使我的 winforms 应用程序在桌面级别保持活跃。

诀窍是在遇到WinKey+D或WinKey+M时将TopMost 属性形式设置为true，其他键设置回false，交出windows句柄来处理.

下面是示例代码。

在 Program.cs - Main()

try
{
    using (var proc = Process.GetCurrentProcess())
    using (var curModule = proc.MainModule)
    {
        var moduleHandle = GetModuleHandle(curModule.ModuleName);
        HookHandle = SetWindowsHookEx(WH_KEYBOARD_LL, IgnoreWin_DOrM, moduleHandle, 0);
    }

    frmForm1 = new frmIGS();
    Application.Run(frmForm1);
}
finally
{
    UnhookWindowsHookEx(HookHandle);
}

然后写你的键盘钩子方法：

static IntPtr IgnoreWin_DOrM(int nCode, IntPtr wParam, IntPtr lParam)
{
    if (nCode == HC_ACTION
        && (IsWin_D(wParam, lParam) || IsWin_M(wParam, lParam)))
    {
        frmForm1.SetTopMost = true;
    }
    else
    {
        //if (frmForm1.SetTopMost)
        {
            frmForm1.SetTopMost = false;
        }
    }

    return CallNextHookEx(HookHandle, nCode, wParam, lParam);
}

static bool IsWin_D(IntPtr wParam, IntPtr lParam)
{
    if ((int)wParam != WM_KEYDOWN)
        return false;

    var keyInfo = (KbHookParam)Marshal.PtrToStructure(lParam, typeof(KbHookParam));
    if (keyInfo.VkCode != (int)Keys.D) return false;
    return GetAsyncKeyState(Keys.LWin) < 0
            || GetAsyncKeyState(Keys.RWin) < 0;
}

static bool IsWin_M(IntPtr wParam, IntPtr lParam)
{
    if ((int)wParam != WM_KEYDOWN)
        return false;

    var keyInfo = (KbHookParam)Marshal.PtrToStructure(lParam, typeof(KbHookParam));
    if (keyInfo.VkCode != (int)Keys.M) return false;
    return GetAsyncKeyState(Keys.LWin) < 0
            || GetAsyncKeyState(Keys.RWin) < 0;
}

我暴露了一个public 属性 for form，它在其代码中设置了最顶层的属性！

private bool topMost = false;
public bool SetTopMost
{
    get
    {
        return topMost;
    }
    set
    {

        this.TopMost = topMost = value;
    }
}

中提琴。现在，无论 windows 键组合如何，我的代码都在后台保持活动状态。但不会停留在其他应用程序之上，让用户做他们的正常工作！这就是要求！

它在 Windows 10 :)

中运行良好

在 Winforms 中捕获 WinKey+D 键序列

Catch WinKey+D key sequence in Winforms

c#

hook

window-messages

winforms