Question

I’m trying to use SendMessage to Notepad, so that I can insert written text without making Notepad the active window.

I have done something like this in the past using SendText, but that required giving Notepad focus.

Now, first I’m retrieving the Windows handle:

Process[] processes = Process.GetProcessesByName('notepad'); Console.WriteLine(processes[0].MainWindowHandle.ToString()); 

I’ve confirmed it’s the right handle for Notepad, the same shown within Windows Task Manager.

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

From here, I haven’t been able to get SendMessage to work in all my experimentation. Am I going in the wrong direction?

Answer 1

    [DllImport('user32.dll', EntryPoint = 'FindWindowEx')]     public static extern IntPtr FindWindowEx(IntPtr hwndParent, IntPtr hwndChildAfter, string lpszClass, string lpszWindow);     [DllImport('User32.dll')]     public static extern int SendMessage(IntPtr hWnd, int uMsg, int wParam, string lParam);     private void button1_Click(object sender, EventArgs e)     {         Process [] notepads=Process.GetProcessesByName('notepad');         if(notepads.Length==0)return;                     if (notepads[0] != null)         {             IntPtr child= FindWindowEx(notepads[0].MainWindowHandle, new IntPtr(0), 'Edit', null);             SendMessage(child, 0x000C, 0, textBox1.Text);         }     } 

WM_SETTEXT=0x000c