WINFORM 发送密钥

Question

我是一个应用程序，要传播。我们从应用程序中选择一个按钮。其次，我们输入小零件，我无法将其连接到钥匙。即“E”被请求切换，并审查这个 E 键“O”。 Note：此问题总结整理于:winform sendkey - Microsoft Q&A

Answer 1

您好，如果即使表单是隐藏的也想运行按键事件，可以尝试使用全局键盘监控（Hook）来做。 下面是一个可以参考的代码示例。

using System;  
using System.Runtime.InteropServices;  
using System.Windows.Forms;  
  
  class KeyboardHook  
    {  
        public event KeyEventHandler KeyDownEvent;  
        public event KeyPressEventHandler KeyPressEvent;  
        public event KeyEventHandler KeyUpEvent;  
  
        public delegate int HookProc(int nCode, Int32 wParam, IntPtr lParam);  
        static int hKeyboardHook = 0;   
                                       
                                       
        public const int WH_KEYBOARD_LL = 13;     
        HookProc KeyboardHookProcedure;   
  
        [StructLayout(LayoutKind.Sequential)]  
        public class KeyboardHookStruct  
        {  
            public int vkCode;    
            public int scanCode;   
            public int flags;    
            public int time;   
            public int dwExtraInfo;   
        }  
   
        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]  
        public static extern int SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hInstance, int threadId);  
  
        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]  
        public static extern bool UnhookWindowsHookEx(int idHook);  
        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]  
        public static extern int CallNextHookEx(int idHook, int nCode, Int32 wParam, IntPtr lParam);  
  
  
        [DllImport("kernel32.dll")]  
        static extern int GetCurrentThreadId();  
  
        [DllImport("kernel32.dll")]  
        public static extern IntPtr GetModuleHandle(string name);  
  
        public void Start()  
        {  
  
            if (hKeyboardHook == 0)  
            {  
                KeyboardHookProcedure = new HookProc(KeyboardHookProc);  
                hKeyboardHook = SetWindowsHookEx(WH_KEYBOARD_LL, KeyboardHookProcedure, GetModuleHandle(System.Diagnostics.Process.GetCurrentProcess().MainModule.ModuleName), 0);  
                
                if (hKeyboardHook == 0)  
                {  
                    Stop();  
                    throw new Exception("Failed to install keyboard hook");  
                }  
            }  
        }  
        public void Stop()  
        {  
            bool retKeyboard = true;  
  
            if (hKeyboardHook != 0)  
            {  
                retKeyboard = UnhookWindowsHookEx(hKeyboardHook);  
                hKeyboardHook = 0;  
            }  
  
            if (!(retKeyboard)) throw new Exception("Failed to uninstall keyboard hook！");  
        }  
        [DllImport("user32")]  
        public static extern int ToAscii(int uVirtKey,   
                                         int uScanCode,   
                                         byte[] lpbKeyState,   
                                         byte[] lpwTransKey,   
                                         int fuState);   
  
  
        [DllImport("user32")]  
        public static extern int GetKeyboardState(byte[] pbKeyState);  
  
        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]  
        private static extern short GetKeyState(int vKey);  
  
        private const int WM_KEYDOWN = 0x100;//KEYDOWN  
        private const int WM_KEYUP = 0x101;//KEYUP  
        private const int WM_SYSKEYDOWN = 0x104;//SYSKEYDOWN  
        private const int WM_SYSKEYUP = 0x105;//SYSKEYUP  
  
        private int KeyboardHookProc(int nCode, Int32 wParam, IntPtr lParam)  
        {  
  
            if ((nCode >= 0) && (KeyDownEvent != null || KeyUpEvent != null || KeyPressEvent != null))  
            {  
                KeyboardHookStruct MyKeyboardHookStruct = (KeyboardHookStruct)Marshal.PtrToStructure(lParam, typeof(KeyboardHookStruct));  
                // raise KeyDown  
                if (KeyDownEvent != null && (wParam == WM_KEYDOWN || wParam == WM_SYSKEYDOWN))  
                {  
                    Keys keyData = (Keys)MyKeyboardHookStruct.vkCode;  
                    KeyEventArgs e = new KeyEventArgs(keyData);  
                    KeyDownEvent(this, e);  
                }  
  
  
                if (KeyPressEvent != null && wParam == WM_KEYDOWN)  
                {  
                    byte[] keyState = new byte[256];  
                    GetKeyboardState(keyState);  
  
                    byte[] inBuffer = new byte[2];  
                    if (ToAscii(MyKeyboardHookStruct.vkCode, MyKeyboardHookStruct.scanCode, keyState, inBuffer, MyKeyboardHookStruct.flags) == 1)  
                    {  
                        KeyPressEventArgs e = new KeyPressEventArgs((char)inBuffer[0]);  
                        KeyPressEvent(this, e);  
                    }  
                }  
  
  
                if (KeyUpEvent != null && (wParam == WM_KEYUP || wParam == WM_SYSKEYUP))  
                {  
                    Keys keyData = (Keys)MyKeyboardHookStruct.vkCode;  
                    KeyEventArgs e = new KeyEventArgs(keyData);  
                    KeyUpEvent(this, e);  
                }  
  
            }  
            return CallNextHookEx(hKeyboardHook, nCode, wParam, lParam);  
        }  
        ~KeyboardHook()  
        {  
            Stop();  
        }  
    }  

你可以在Form_Load事件中使用它。

private void Form1_Load(object sender, EventArgs e)  
        {  
            var k_hook = new KeyboardHook();  
            k_hook.KeyDownEvent += new KeyEventHandler(hook_KeyDown);  
            k_hook.Start();  
        }  
        private void hook_KeyDown(object sender, KeyEventArgs e)  
        {  
  
            if (e.KeyValue >= (int)Keys.A &&e.KeyValue<=(int)Keys.Z )  
            {  
                System.Windows.Forms.MessageBox.Show(e.KeyCode.ToString());  
            }  
        }  

如果答案是正确的，请点击“接受答案”并点赞。 如果您对此答案还有其他疑问，请点击“评论”。 注意：如果您想接收相关电子邮件，请按照我们的文档中的步骤启用电子邮件通知 此线程的通知。