Bringing focus to an window if app already running.

I'm using a Mutex to check for instances of an app already running and use a message box to inform the user if it's already running but I would like to just have it restore the window to focus (say if its minimized or behind other active windows).

I tried using ShowWindow with SW_RESTORE but that doesn't wanna work, anyone have any ideas?

This has been discussed here:

http://www.cprogramming.com/cboard/s...?threadid=8963

(How do you allow only one instance of an app?)

If you take 'Unregistered' sample code and insert 'No-One's'
sample code into it once GetLastError has returned ERROR_ALREADY_EXISTS then use ShowWindow on the returned handle from FindWindow that should do it.

Which is probably too surreal so (credit to Unregistered & No-One) :

Code:

---

HANDLE hMutex=CreateMutex(NULL, FALSE, "myAppMutex");
if (hMutex)
    {
    if (GetLastError() == ERROR_ALREADY_EXISTS)
      {
      HWND hwnd=FindWindow(lpClassName, lpWindow);
      if (hwnd)
          {
          ShowWindow(hwnd,SW_SHOW);
          UpdateWindow(hwnd);  //for good measure
          }
        }
    }

---

where lpClassName is pointer to class name and lpWindow is pointer to window name.

I think that should about do it....but don't quote me on that! ;)

This works, just add it to the beginning of WinMain.

Code:

---

    /* Vars */
  HANDLE hMutex; // Mutex Handle
  HWND hwndShow; // Find Window HWND

    /* Create A Mutex To Register Program Is Running */
    hMutex = CreateMutex(
        NULL,
        FALSE,
        "myMutex"
    );

    /* If Program Is Already Running, Show Program & Stop */
    if (hMutex) {

        if (GetLastError() == ERROR_ALREADY_EXISTS) {

            // Replace WINCLASS_HERE with name of your class
            hwndShow = FindWindow(WINCLASS_HERE, NULL);

            if (hwndShow) {

                // Minimize The Program So It Can Be Restored
                ShowWindow(hwndShow, SW_MINIMIZE);
                UpdateWindow(hwndShow);

                // Restore The Program In Its Original State
                ShowWindow(hwndShow, SW_RESTORE);
                UpdateWindow(hwndShow);

          } 
          ExitProcess(1);

        }
    }

---

Make sure to change the code to reflect your Window class. You don't have to include the SW_MINIMIZE ShowWindow, its just there to make sure the window shows no matter how many other maximized windows you have.