Activation for mouse and keyboard

Hello...

I am with problems in the attached code to this menssagem. My intention is to create a class with option to drag and drop, I implemented this with WM_NCHITTEST.

I am trying to create a way to keep only one active window for time, and I'm not obtaining, I think that for bad use of the messagens WM_ACTIVATE, WM_NCACTIVATE, WM_ACTIVATEAPP, WM_MOUSEACTIVATE, WM_SETFOCUS and WM_KILLFOCUS.

I desire to activate the windows by input of the mouse and of the keyboard (a window for time).

I appreciate any aid...

I made, I want only one opinion about code.

Code:

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#include <windows.h>

#define CHILDCLASS  "CHILDCLASS"
#define INACTIVATE  0
#define ACTIVATE    1

LRESULT CALLBACK WindowProc(HWND, UINT, WPARAM, LPARAM);
LRESULT CALLBACK ChildWinProc(HWND, UINT, WPARAM, LPARAM);
BOOL InitChildControl();

char szClassName[ ] = "WindowsApp";

int WINAPI WinMain (HINSTANCE hThisInstance,
                    HINSTANCE hPrevInstance,
                    LPSTR lpszArgument,
                    int nFunsterStil)

{
  HWND hwnd;
  MSG messages;
  WNDCLASSEX wincl;

  wincl.hInstance = hThisInstance;
  wincl.lpszClassName = szClassName;
  wincl.lpfnWndProc = WindowProc;
  wincl.style = CS_DBLCLKS;
  wincl.cbSize = sizeof (WNDCLASSEX);

  wincl.hIcon = LoadIcon (NULL, IDI_APPLICATION);
  wincl.hIconSm = LoadIcon (NULL, IDI_APPLICATION);
  wincl.hCursor = LoadCursor (NULL, IDC_ARROW);
  wincl.lpszMenuName = NULL;
  wincl.cbClsExtra = 0;
  wincl.cbWndExtra = 0;
  wincl.hbrBackground = (HBRUSH)COLOR_BTNSHADOW;

  if(!RegisterClassEx(&wincl))
    return 0;

  if(!InitChildControl())
    return 0;

  hwnd = CreateWindowEx (
          0,
          szClassName,
          "Windows App",
          WS_OVERLAPPEDWINDOW,
          CW_USEDEFAULT,
          CW_USEDEFAULT,
          544,
          375,
          HWND_DESKTOP,
          NULL,
          hThisInstance,
          NULL
          );

  ShowWindow (hwnd, nFunsterStil);

  while(GetMessage(&messages, NULL, 0, 0))
  {
      if(!IsDialogMessage(hwnd,&messages))
      {
        TranslateMessage(&messages);
        DispatchMessage(&messages);
      }
  }

  return messages.wParam;
}

LRESULT CALLBACK ChildWinProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
  static RECT rc;
  long ActParamAnt;
  long ActParam = ActParamAnt = GetWindowLongPtr(hwnd, GWL_USERDATA);

  switch(message)
  {
      case WM_PAINT:
      {
        PAINTSTRUCT ps;

        GetClientRect(hwnd,&rc);

        if(BeginPaint(hwnd,&ps))
        {
            if(ActParam == ACTIVATE)
            {
              FillRect(ps.hdc,&rc,(HBRUSH)4);

              SetBkMode(ps.hdc,TRANSPARENT);
              DrawText(ps.hdc,"ACTIVE",6,&rc,DT_SINGLELINE|DT_CENTER|DT_VCENTER);
            }
            else
            {
              FillRect(ps.hdc,&rc,(HBRUSH)13);

              SetBkMode(ps.hdc,TRANSPARENT);
              DrawText(ps.hdc,"INACTIVE",8,&rc,DT_SINGLELINE|DT_CENTER|DT_VCENTER);
            }

            EndPaint(hwnd,&ps);
        }
      }break;

      case WM_MOUSEACTIVATE:
      {
        if(LOWORD(lParam) == HTNOWHERE)
        {
            ActParam = INACTIVATE;
            SetFocus(hwnd);
            InvalidateRect(hwnd,NULL,TRUE);

            return MA_NOACTIVATE;
        }
        else
        {
            ActParam = ACTIVATE;
            SetFocus(hwnd);
            InvalidateRect(hwnd,NULL,TRUE);

            return MA_ACTIVATE;
        }
      }break;

      case WM_SETFOCUS:
      {
        ActParam = ACTIVATE;
        InvalidateRect(hwnd,NULL,TRUE);
      }break;

      case WM_KILLFOCUS:
      {
        ActParam = INACTIVATE;
        InvalidateRect(hwnd,NULL,TRUE);
      }break;

      case WM_NCLBUTTONDBLCLK:
      {
        return 0;
      }break;

      case WM_NCHITTEST:
      {
        return HTCAPTION;
      }break;

      default:
        return DefWindowProc(hwnd, message, wParam, lParam);
  }
 
  if(ActParamAnt != ActParam)SetWindowLongPtr(hwnd, GWL_USERDATA, ActParam);
    return 0;
}

BOOL InitChildControl()
{
  WNDCLASSEX Wnd;

  Wnd.cbSize = sizeof(WNDCLASSEX);
  Wnd.lpszClassName = CHILDCLASS;
  Wnd.lpfnWndProc = ChildWinProc;
  Wnd.hInstance = GetModuleHandle(NULL);
  Wnd.style = CS_HREDRAW|CS_VREDRAW;
  Wnd.hIcon = LoadIcon (NULL, IDI_APPLICATION);
  Wnd.hIconSm = LoadIcon (NULL, IDI_APPLICATION);
  Wnd.hCursor = LoadCursor (NULL, IDC_ARROW);
  Wnd.lpszMenuName = NULL;
  Wnd.cbClsExtra = 0;
  Wnd.cbWndExtra = 0;
  Wnd.hbrBackground = (HBRUSH)COLOR_BTNSHADOW;

  if(!RegisterClassEx(&Wnd))
  {
      return FALSE;
  }

  return TRUE;
}

LRESULT CALLBACK WindowProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
  static HWND Control[4];

  switch (message)
  {
      case WM_CREATE:
      {
        Control[0] = CreateWindow(CHILDCLASS,"",WS_CHILD|WS_VISIBLE|WS_TABSTOP,10,10,85,25,hwnd,NULL,GetModuleHandle(NULL),NULL);
        Control[1] = CreateWindow(CHILDCLASS,"",WS_CHILD|WS_VISIBLE|WS_TABSTOP,110,10,85,25,hwnd,NULL,GetModuleHandle(NULL),NULL);
        Control[2] = CreateWindow(CHILDCLASS,"",WS_CHILD|WS_VISIBLE|WS_TABSTOP,210,10,85,25,hwnd,NULL,GetModuleHandle(NULL),NULL);
        Control[3] = CreateWindow(CHILDCLASS,"",WS_CHILD|WS_VISIBLE|WS_TABSTOP,310,10,85,25,hwnd,NULL,GetModuleHandle(NULL),NULL);
      }break;

      case WM_DESTROY:
        PostQuitMessage (0);
        break;

      default:
        return DefWindowProc(hwnd, message, wParam, lParam);
  }

  return 0;
}

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bye