NativeWindowHandle Returns 0, but Spy displays handle

Question

I am trying to automate a process in a application. The Spy++ representation of this process when I do it manually looks like:

WINDOW 002F0B08
002F0B08 P WM_LBUTTONDOWN fwKeys:MK_LBUTTON xPOS:# ypos:# (Start Pos)
002F0B08 P WM_MOUSEMOVE fwKeys:MK_LBUTTON xPOS:# ypos:#
...
002F0B08 P WM_LBUTTONUP fwKeys:MK_LBUTTON xPOS:# ypos:# (Final Pos)

WINDOW 007406BC
007406BC P WM_KEYDOWN fwKeys:VK_CONTROL ...
007406BC P WM_KEYDOWN fwKeys:VK_C ...
007406BC P WM_KEYUP fwKeys:VK_CONTROL ...
007406BC P WM_KEYUP fwKeys:VK_C ...

The goal is to select an area and copy the area to the clipbard. I am able to perform the first part by using PostMessage:

PostMessage(PanelHandle, WM_LBUTTONDOWN, (int)MK_LBUTTON, new IntPtr(lParam)); //send left mouse button down

and this is reflected in Spy++ Message Window, but for some reason it is not working for the window which reflects CTRL+C when I do it manually.

The entire code is:

class MouseControl
    {
        [DllImport("user32.dll")]
        static extern bool PostMessage(IntPtr hWnd, uint Msg, int wParam, IntPtr lParam);

        [DllImport("user32.dll")]
        public static extern IntPtr FindWindow(string lpClassName, string lpWindowName);


        [DllImport("user32.dll", CallingConvention = CallingConvention.StdCall)]
        static extern void mouse_event(MouseEventFlags flags, uint dx, uint dy, uint delta, IntPtr extraInfo);

        public static void Select(AutomationElement window)
        {
            AutomationElement main = null;
            AutomationElement panel = window.FindFirst(TreeScope.Descendants, new PropertyCondition(AutomationElement.AutomationIdProperty, "2"));
            main = window.FindFirst(TreeScope.Descendants, new PropertyCondition(AutomationElement.NameProperty, "Session A - [24 x 80]"));
            Console.WriteLine("Got Panel: {0} , {1}", panel.ToString(), (new IntPtr(panel.Current.NativeWindowHandle)).ToString());
            Console.WriteLine("Got Main: {0} , {1}", main.ToString(), (new IntPtr(main.Current.NativeWindowHandle)).ToString());

            if (main == null)
                Console.WriteLine("Could not find main");

            // GET REF POINT IN WINDOW
            System.Windows.Point p = panel.GetClickablePoint();

           // LeftMouseDown();
           // LeftMouseUp();

            double new_X = p.X-400;
            double new_Y = p.Y-800;

            const uint WM_LBUTTONDOWN = 0x0201;
            const uint WM_LBUTTONUP = 0x0202;
            const uint MK_LBUTTON = 0x1;
            const uint WM_MOUSEMOVE = 0x0200;
            const uint WM_KEYDOWN = 0x100;
            const uint WM_KEYUP = 0x101;
            const uint VK_C = 0x043;
            const uint VK_CONTROL = 0x011;


            IntPtr PanelHandle = new IntPtr(panel.Current.NativeWindowHandle);
            IntPtr WindowHandle = new IntPtr(main.Current.NativeWindowHandle);

            Console.WriteLine("Press Return To Start");
            Console.ReadLine();

            //LeftMouseDown();
            int lParam = (((int)new_Y << 16) | ((int)new_X & 0xffff));
            PostMessage(PanelHandle, WM_LBUTTONDOWN, (int)MK_LBUTTON, new IntPtr(lParam));//send left mouse button down
            Console.WriteLine("Tried");
            while (new_X < p.X + 100)
            {

                lParam = (((int)new_X << 16) | ((int)new_Y & 0xffff));
                PostMessage(PanelHandle, WM_MOUSEMOVE, (int)MK_LBUTTON, new IntPtr(lParam));//send left mouse button down

                new_X += 1;
                new_Y += 1;
            }

            PostMessage(PanelHandle, WM_LBUTTONUP, (int)MK_LBUTTON, new IntPtr(lParam));//send left mouse button down
            Console.WriteLine("WM_LBUTTONUP, MK_LBUTTON, {1}  was sent to {0}", PanelHandle, lParam);

            PostMessage(WindowHandle, WM_KEYDOWN, (int)VK_CONTROL, IntPtr.Zero);
            Console.WriteLine("WM_KEYDOWN, VK_CONTROL  was sent to {0}", WindowHandle);

            PostMessage(WindowHandle, WM_KEYDOWN, (int)VK_C, IntPtr.Zero);
            Console.WriteLine("WM_KEYDOWN, VK_C was sent to {0}", WindowHandle);

            PostMessage(WindowHandle, WM_KEYUP, (int)VK_CONTROL, IntPtr.Zero);
            Console.WriteLine("WM_KEYUP, VK_CONTROL  was sent to {0}", WindowHandle);

            PostMessage(WindowHandle, WM_KEYUP, (int)VK_C, IntPtr.Zero);
            Console.WriteLine("WM_KEYUP, VK_C was sent to {0}", WindowHandle);
        }
    }

The Console Displays:

Got Panel: ... , 3083016 (handle displayed in Spy++: 002F0B08

Got Main: ... , 0 (handle displayed in Spy++: 007406BC

Press Return To Start

Tried

WM_LBUTTONUP, MK_LBUTTON, 61538539 was sent to 3213992

WM_KEYDOWN, VK_CONTROL was sent to 0

WM_KEYDOWN, VK_C was sent to 0

WM_KEYUP, VK_CONTROL was sent to 0

WM_KEYUP, VK_C was sent to 0

It successfully selects the area but is unable to copy the area. The CTRL + C message is not sending to the window which performs the copy function.

EDIT: I managed to get it to work (not as desired, but fine for now) by manually retrieving the handle from Spy++ using:

var hwnd = new IntPtr(Convert.ToInt32(Console.ReadLine(), 16));
IntPtr WindowHandle = hwnd;

However it does not perform a copy. This is the manual copy from Spy++:

<00271> 00390640 P WM_KEYDOWN nVirtKey:VK_CONTROL cRepeat:1 ScanCode:1D fExtended:0 fAltDown:0 fRepeat:0 fUp:0
<00368> 00390640 P WM_KEYDOWN nVirtKey:'C' cRepeat:1 ScanCode:2E fExtended:0 fAltDown:0 fRepeat:0 fUp:0
<00375> 00390640 P WM_KEYUP nVirtKey:'C' cRepeat:1 ScanCode:2E fExtended:0 fAltDown:0 fRepeat:1 fUp:1
<00376> 00390640 P WM_KEYUP nVirtKey:VK_CONTROL cRepeat:1 ScanCode:1D fExtended:0 fAltDown:0 fRepeat:1 fUp:1

And this is what my program does:

<00013> 00390640 P WM_KEYDOWN nVirtKey:VK_CONTROL cRepeat:0 ScanCode:00 fExtended:0 fAltDown:0 fRepeat:0 fUp:0
<00014> 00390640 P WM_KEYDOWN nVirtKey:'C' cRepeat:0 ScanCode:00 fExtended:0 fAltDown:0 fRepeat:0 fUp:0
<00015> 00390640 P WM_KEYUP nVirtKey:VK_CONTROL cRepeat:0 ScanCode:00 fExtended:0 fAltDown:0 fRepeat:0 fUp:0
<00016> 00390640 P WM_KEYUP nVirtKey:'C' cRepeat:0 ScanCode:00 fExtended:0 fAltDown:0 fRepeat:0 fUp:0

Any ideas on why this isn't working?

Answer 1

Couple of things wrong here.

1. NativeWindowHandle can often be 0 if the control in question is windowless. Since all windowless controls have to be hosted in some window (even if it's the top-level window), Spy++ will always show the (host) window that the message will go to. If you really need a NativeWindowHandle, you can walk up the automation parent chain until you find a NativeWindowHandle that's not NULL.
2. Rather than posting mouse/keyboard messages, you should be using UI Automation methods (e.g., SetFocus), or at least using SendInput to send mouse/keyboard events. There's a lot of stuff that happens "under the covers" that posting messages simply doesn't do. (E.g., activation, keyboard state management, etc.)