Unable to find an entry point named 'SendMessage' in DLL 'User32.dll'

Unable to find an entry point named 'SendMessage' in DLL 'User32.dll',报这个错误是因为你函数的放口写错了。正确的应该如下：
windows 10 User32.dll SendMessage not work

[DllImport("user32.dll", EntryPoint = "SendMessageA")]
        private static extern int SendMessage(IntPtr hwnd, uint wMsg, IntPtr wParam, IntPtr lParam);

[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        static extern IntPtr SendMessage(IntPtr hWnd, uint Msg, uint wParam, uint lParam);

  [DllImport("User32.dll", CharSet = CharSet.Auto, SetLastError = true, ExactSpelling = true)]
  private static extern IntPtr SendMessageW(IntPtr hWnd, int Msg, IntPtr wParam, IntPtr lParam);

错误的使用是添加了 EntryPoint = "SendMessage" 例如：

[DllImport("user32.dll", EntryPoint = "SendMessage")]
        private static extern int SendMessage(IntPtr hwnd, uint wMsg, IntPtr wParam, IntPtr lParam);

正确的入口应该是EntryPoint = "SendMessageA"。