Thread: Help me learn to use accelerators

hi, i am trying to learn how to use accelerators.

Here's what i have done so far


in my main message loop :

Code:

	
	HACCEL 	haccel = LoadAccelerators( GetModuleHandle(0),   MAKEINTRESOURCE(IDC_AINTERFACE)  );

	while(GetMessage(&Msg, NULL, 0, 0) > 0)
	{
		TranslateAccelerator(calc_hwnd,      // handle to receiving dialog right?			haccel,        // handle to active accelerator table 
			&Msg)   ;   // message data */
			

			TranslateMessage(&Msg);
			DispatchMessage(&Msg);
	}

For calc_hwnd's callback function, where there's a problem

Code:

BOOL CALLBACK calcproc(HWND hwnd, UINT Message, WPARAM wParam, LPARAM lParam)
{
    switch(Message)
    {
        case WM_INITDIALOG:
			{
			SendDlgItemMessage(hwnd,IDC_HOUR, EM_SETLIMITTEXT, (WPARAM)2,0);
			SendDlgItemMessage(hwnd,IDC_MIN, EM_SETLIMITTEXT, (WPARAM)2,0);
			break;
			}
        return TRUE;
        case WM_COMMAND:
            switch(LOWORD(wParam))
            {
              /*  case IDOK:
                    EndDialog(hwnd, IDOK);
                break;
                case IDCANCEL:
                    EndDialog(hwnd, IDCANCEL);
                break;*/

			case IDM_TAB:
				{
					int a = 5;  // !!PROBLEM PROBLEM !! : here where a doesnt become 5 because no "IDM_TAB" message was received.
				}
				break;

			case IDC_EXIT:
				{
					EndDialog(calc_hwnd, IDOK);
					EnableWindow(dia_hwnd, TRUE);

					break;
				}

            }
        break;
        default:
            return FALSE;
    }
    return TRUE;
}

The name of my accelerator resource is IDC_AINTERFACE.
I defined it such that the ID "IDM_TAB" has key "VK_TAB" of type "VIRTKEY"


I believe there's something very wrong with this. can anyonoe pls correct me?


using
- win 98se
- API Style
- vc++6.0

I can't see anything wrong with your code. All I can think of is:

1. Under 'case IDM_TAB', put a call to MessageBox():

Code:

MessageBox(NULL,"tab pressed",NULL,NULL);

That will tell us for sure whether or not the point is being reached.

2. Check to make sure the accelerator table was loaded correctly:

Code:

HACCEL 	haccel = LoadAccelerators( GetModuleHandle(0),   MAKEINTRESOURCE(IDC_AINTERFACE)  );
if (!haccel)
    MessageBox(NULL,"Accelerator Table not loaded correctly",NULL,NULL);

That should narrow the problem down.

Also make sure that you are properly trapping accelerator keys in your WM_COMMAND (see wParam parameter description) handler by checking that HIWORD(wParam)=1, eg;

Code:

if (HIWORD(wParam)==1 && LOWORD(wParam)==IDM_TAB)
  {
  /*accelerator key 'IDM_TAB' pressed
  }

Your code may seem to work but it is still incorrect. All that is happening is, any WM_COMMAND message, which could mean any number of things, is simply executing the code under 'case IDM_TAB:', because there is no 'break' or 'return'. Try clicking a button or control, you will get the message "TAB PRESSED" as well.

Could you please zip up your entire project folder (minus the executable) and post it here? There must be some small detail that is preventing this from working.