Retrieving the Names of Simultaneous Tasks Under Windows

The information in this article applies to:

• Microsoft Windows Software Development Kit (SDK) for Windows versions 3.0 and 3.1

SUMMARY

There are situations when it is necessary for an application to obtain a list of all applications that are running in the Windows environment at a particular time.

In Windows 3.0, instead of using the EnumWindows() function and an application-supplied callback function to enumerate all parent windows, the application can retrieve a handle to the first window in the task list and walk through the list to obtain the names of all windows in the task list.

In Windows 3.1, however, an application should instead use the ToolHelp Library functions. More specifically, use TaskFirst(), TaskNext(), ModuleFirst(), and ModuleNext().

NOTE: Since the ToolHelp functions work in Windows 3.0 and since ToolHelp is itself a redistributable library, these functions can be safely used in Windows 3.0 also.

MORE INFORMATION

The most efficient way to retrieve the name of each task running under Windows 3.0 is to use the GetWindow() function. GetWindow (hwnd, GW_HWNDFIRST) provides the handle to the first window in the task list. The application can walk through the task list by calling GetWindow (hwndCurrent, GW_HWNDNEXT). The following example demonstrates how to obtain a handle to each top-level window. The GetWindowText() function provides the name of each window from its handle.

    hwndNext = GetWindow(hWnd, GW_HWNDFIRST);
    /* Where: hWnd is the original/current window. GW_HWNDFIRST will
       return the first sibling window for a child window, otherwise
       it returns the first top-level window in the system's list of
       top-level windows */
    while (hwndNext)
    {
       if ((hwndNext != hWnd) &&  // Do not get this application's
                                  // name.
           (IsWindowVisible(hwndNext)) &&
           (!GetWindow(hwndNext, GW_OWNER)))
       {
          if (GetWindowText(hwndNext, (LPSTR)szTemp, sizeof(szTemp)))
          {
            // This is a valid top-level window handle.
            // Its name is in szTemp...
          }
       }
       hwndNext = GetWindow(hwndNext, GW_HWNDNEXT);
    }