C#獲得光標在屏幕中的位置並在位置處輸入指定文字

實現目標：C#獲得光標在屏幕中的位置並在位置處輸入指定文字。

實現示例：鼠標光標定位到屏幕的任意輸入位置，按F1快捷鍵快速輸入當前時間。

實現思路：（1）首先監聽F1鍵盤按下事件；（2）獲取前台窗口的句柄；檢索創建窗口的線程信息；發送消息。

程序類型：Winform

實現過程：

首先，定義兩個幫助類，一個是鍵盤監聽事件類KeyboardHook，一個是發送消息類SendMsg。

KeyboardHook：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Helper
{
    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; //聲明鍵盤鈎子處理的初始值
                                      //值在Microsoft SDK的Winuser.h里查詢
        public const int WH_KEYBOARD_LL = 13;   //線程鍵盤鈎子監聽鼠標消息設為2，全局鍵盤監聽鼠標消息設為13
        HookProc KeyboardHookProcedure; //聲明KeyboardHookProcedure作為HookProc類型
                                        //鍵盤結構
        [StructLayout(LayoutKind.Sequential)]
        public class KeyboardHookStruct
        {
            public int vkCode;  //定一個虛擬鍵碼。該代碼必須有一個價值的范圍1至254
            public int scanCode; // 指定的硬件掃描碼的關鍵
            public int flags;  // 鍵標志
            public int time; // 指定的時間戳記的這個訊息
            public int dwExtraInfo; // 指定額外信息相關的信息
        }
        //使用此功能，安裝了一個鈎子
        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
        public static extern int SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hInstance, int threadId);


        //調用此函數卸載鈎子
        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
        public static extern bool UnhookWindowsHookEx(int idHook);


        //使用此功能，通過信息鈎子繼續下一個鈎子
        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
        public static extern int CallNextHookEx(int idHook, int nCode, Int32 wParam, IntPtr lParam);

        // 取得當前線程編號（線程鈎子需要用到）
        [DllImport("kernel32.dll")]
        static extern int GetCurrentThreadId();

        //使用WINDOWS API函數代替獲取當前實例的函數,防止鈎子失效
        [DllImport("kernel32.dll")]
        public static extern IntPtr GetModuleHandle(string name);

        public void Start()
        {
            // 安裝鍵盤鈎子
            if (hKeyboardHook == 0)
            {
                KeyboardHookProcedure = new HookProc(KeyboardHookProc);
                hKeyboardHook = SetWindowsHookEx(WH_KEYBOARD_LL, KeyboardHookProcedure, GetModuleHandle(System.Diagnostics.Process.GetCurrentProcess().MainModule.ModuleName), 0);
                //hKeyboardHook = SetWindowsHookEx(WH_KEYBOARD_LL, KeyboardHookProcedure, Marshal.GetHINSTANCE(Assembly.GetExecutingAssembly().GetModules()[0]), 0);
                //************************************
                //鍵盤線程鈎子
                SetWindowsHookEx(13, KeyboardHookProcedure, IntPtr.Zero, GetCurrentThreadId());//指定要監聽的線程idGetCurrentThreadId(),
                                                                                               //鍵盤全局鈎子,需要引用空間(using System.Reflection;)
                                                                                               //SetWindowsHookEx( 13,MouseHookProcedure,Marshal.GetHINSTANCE(Assembly.GetExecutingAssembly().GetModules()[0]),0);
                                                                                               //
                                                                                               //關於SetWindowsHookEx (int idHook, HookProc lpfn, IntPtr hInstance, int threadId)函數將鈎子加入到鈎子鏈表中，說明一下四個參數：
                                                                                               //idHook 鈎子類型，即確定鈎子監聽何種消息，上面的代碼中設為2，即監聽鍵盤消息並且是線程鈎子，如果是全局鈎子監聽鍵盤消息應設為13，
                                                                                               //線程鈎子監聽鼠標消息設為7，全局鈎子監聽鼠標消息設為14。lpfn 鈎子子程的地址指針。如果dwThreadId參數為0 或是一個由別的進程創建的
                                                                                               //線程的標識，lpfn必須指向DLL中的鈎子子程。 除此以外，lpfn可以指向當前進程的一段鈎子子程代碼。鈎子函數的入口地址，當鈎子鈎到任何
                                                                                               //消息后便調用這個函數。hInstance應用程序實例的句柄。標識包含lpfn所指的子程的DLL。如果threadId 標識當前進程創建的一個線程，而且子
                                                                                               //程代碼位於當前進程，hInstance必須為NULL。可以很簡單的設定其為本應用程序的實例句柄。threaded 與安裝的鈎子子程相關聯的線程的標識符
                                                                                               //如果為0，鈎子子程與所有的線程關聯，即為全局鈎子
                                                                                               //************************************
                                                                                               //如果SetWindowsHookEx失敗
                if (hKeyboardHook == 0)
                {
                    Stop();
                    throw new Exception("安裝鍵盤鈎子失敗");
                }
            }
        }
        public void Stop()
        {
            bool retKeyboard = true;


            if (hKeyboardHook != 0)
            {
                retKeyboard = UnhookWindowsHookEx(hKeyboardHook);
                hKeyboardHook = 0;
            }

            if (!(retKeyboard)) throw new Exception("卸載鈎子失敗！");
        }
        //ToAscii職能的轉換指定的虛擬鍵碼和鍵盤狀態的相應字符或字符
        [DllImport("user32")]
        public static extern int ToAscii(int uVirtKey, //[in] 指定虛擬關鍵代碼進行翻譯。
                                         int uScanCode, // [in] 指定的硬件掃描碼的關鍵須翻譯成英文。高階位的這個值設定的關鍵，如果是（不壓）
                                         byte[] lpbKeyState, // [in] 指針，以256字節數組，包含當前鍵盤的狀態。每個元素（字節）的數組包含狀態的一個關鍵。如果高階位的字節是一套，關鍵是下跌（按下）。在低比特，如果設置表明，關鍵是對切換。在此功能，只有肘位的CAPS LOCK鍵是相關的。在切換狀態的NUM個鎖和滾動鎖定鍵被忽略。
                                         byte[] lpwTransKey, // [out] 指針的緩沖區收到翻譯字符或字符。
                                         int fuState); // [in] Specifies whether a menu is active. This parameter must be 1 if a menu is active, or 0 otherwise.

        //獲取按鍵的狀態
        [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)
        {
            // 偵聽鍵盤事件
            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);
                }

                //鍵盤按下
                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);
                    }
                }

                // 鍵盤抬起
                if (KeyUpEvent != null && (wParam == WM_KEYUP || wParam == WM_SYSKEYUP))
                {
                    Keys keyData = (Keys)MyKeyboardHookStruct.vkCode;
                    KeyEventArgs e = new KeyEventArgs(keyData);
                    KeyUpEvent(this, e);
                }

            }
            //如果返回1，則結束消息，這個消息到此為止，不再傳遞。
            //如果返回0或調用CallNextHookEx函數則消息出了這個鈎子繼續往下傳遞，也就是傳給消息真正的接受者
            return CallNextHookEx(hKeyboardHook, nCode, wParam, lParam);
        }
        ~KeyboardHook()
        {
            Stop();
        }
    }
}

SendMsg：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;

namespace Helper
{
    class SendMsg
    {
        [DllImport("user32.dll")]
        public static extern IntPtr GetForegroundWindow();
        [DllImport("user32.dll", CharSet = CharSet.Auto)]
        public static extern IntPtr SendMessage(IntPtr hWnd, uint Msg, IntPtr wParam, IntPtr lParam);
        [DllImport("user32.dll")]
        static extern uint GetWindowThreadProcessId(IntPtr hWnd, IntPtr ProcessId);
        [DllImport("user32.dll")]
        static extern bool GetGUIThreadInfo(uint idThread, ref GUITHREADINFO lpgui);
        [StructLayout(LayoutKind.Sequential)]
        public struct GUITHREADINFO
        {
            public int cbSize;
            public int flags;
            public IntPtr hwndActive;
            public IntPtr hwndFocus;
            public IntPtr hwndCapture;
            public IntPtr hwndMenuOwner;
            public IntPtr hwndMoveSize;
            public IntPtr hwndCaret;
            public RECT rectCaret;
        }

        [StructLayout(LayoutKind.Sequential)]
        public struct RECT
        {
            int left;
            int top;
            int right;
            int bottom;
        }
        public GUITHREADINFO? GetGuiThreadInfo(IntPtr hwnd)
        {
            if (hwnd != IntPtr.Zero)
            {
                uint threadId = GetWindowThreadProcessId(hwnd, IntPtr.Zero);
                GUITHREADINFO guiThreadInfo = new GUITHREADINFO();
                guiThreadInfo.cbSize = Marshal.SizeOf(guiThreadInfo);
                if (GetGUIThreadInfo(threadId, ref guiThreadInfo) == false)
                    return null;
                return guiThreadInfo;
            }
            return null;
        }

        public void SendText(string text)
        {
            IntPtr hwnd = GetForegroundWindow();
            if (String.IsNullOrEmpty(text))
                return;
            GUITHREADINFO? guiInfo = GetGuiThreadInfo(hwnd);
            if (guiInfo != null)
            {
                for (int i = 0; i < text.Length; i++)
                {
                    SendMessage(guiInfo.Value.hwndFocus, 0x0102, (IntPtr)(int)text[i], IntPtr.Zero);
                }
            }
        }
    }
}

調用方法：

using Helper;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WindowsFormsApp1
{
    public partial class Form1 : Form
    {
        KeyboardHook k_hook;
        public Form1()
        {
            InitializeComponent();
            k_hook = new KeyboardHook();
            k_hook.KeyDownEvent += K_hook_KeyDownEvent;
            k_hook.Start();
        }

        private void K_hook_KeyDownEvent(object sender, KeyEventArgs e)
        {
            if (e.KeyCode == Keys.F1)
            {
                SendMsg sendMsg = new SendMsg();
                sendMsg.SendText(DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"));
            }
        }
    }
}

此時，可以運行程序，進行測試了。

打開windows微信客戶端，光標定位到信息發送窗，此時按F1，會自動輸入當前時間字符串。