C# 通过进程名/进程Id 操作窗口/程序

1. 判断窗口是否存在

     private bool IsWindowExist(IntPtr handle)
     {
         return (!(GetWindow(new HandleRef(this, handle), ) != IntPtr.Zero) && IsWindowVisible(new HandleRef(this, handle)));
     }

     [DllImport("user32.dll", CharSet = CharSet.Auto, ExactSpelling = true)]
     public static extern IntPtr GetWindow(HandleRef hWnd, int uCmd);

     [DllImport("user32.dll", CharSet = CharSet.Auto)]
     public static extern bool IsWindowVisible(HandleRef hWnd);

2. 获取窗口句柄

     /// <summary>
     /// 获取应用程序窗口句柄
     /// </summary>
     /// <param name="processId"></param>
     /// <returns></returns>
     private IntPtr GetWindowHandle(int processId)
     {
         var windowHandle = IntPtr.Zero;
         EnumThreadWindowsCallback windowsCallback = new EnumThreadWindowsCallback(FindMainWindow);
         EnumWindows(windowsCallback, IntPtr.Zero);
         //保持循环
         GC.KeepAlive(windowsCallback);

         bool FindMainWindow(IntPtr handle, IntPtr extraParameter)
         {
             int num;
             GetWindowThreadProcessId(new HandleRef(this, handle), out num);
             if (num == processId && IsWindowExist(handle))
             {
                 windowHandle = handle;
                 return true;
             }
             return false;
         }

         return windowHandle;
     }
     public delegate bool EnumThreadWindowsCallback(IntPtr hWnd, IntPtr lParam);

     [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
     public static extern bool EnumWindows(EnumThreadWindowsCallback callback, IntPtr extraData);

     [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
     public static extern int GetWindowThreadProcessId(HandleRef handle, out int processId);

3. 关闭应用窗口

根据进程Id关闭应用窗口：

     /// <summary>
     /// 关闭程序主窗口
     /// </summary>
     /// <param name="processId">进程ID</param>
     public void CloseWindow(int processId)
     {
         var mwh = GetWindowHandle(processId);
         SendMessage(mwh, MW_CLOSE, , );
     }
     const int MW_CLOSE = 0x0010;

     [DllImport("User32.dll", EntryPoint = "SendMessage")]
     private static extern int SendMessage(IntPtr hWnd, int Msg, int wParam, int lParam);

关闭所有此进程名的窗口：

         public void CloseAllWindows(string processName)
         {
             Process[] processList = Process.GetProcessesByName(processName);
             foreach (Process process in processList)
             {
                 CloseMainWindow(process.Id);
             }
         }

当然，直接杀进程，是最快的方法：

     /// <summary>
     /// 关闭所有进程
     /// </summary>
     /// <param name="processName"></param>
     /// <returns></returns>
     public static bool CloseAllProcesses(string processName)
     {
         try
         {
             Process[] psEaiNotes = Process.GetProcessesByName(processName);
             foreach (Process psEaiNote in psEaiNotes)
             {
                 psEaiNote.Kill();
             }
         }
         catch
         {
             return false;
         }

         return true;
     }

4. 重启程序

     string appFileName = currentClientProcess.MainModule.FileName;

     Process newClient = new Process();
     newClient.StartInfo.FileName = appFileName;
     // 设置要启动的进程的初始目录
     newClient.StartInfo.WorkingDirectory = System.Windows.Forms.Application.ExecutablePath;

     //启动程序
     currentClientProcess.Kill();
     newClient.Start();

窗口之间发送/接收消息的处理，请参考《C# 跨进程通信》