How to Modify a Report Preview Window Property

• Microsoft Visual FoxPro for Windows, versions 3.0, 3.0b

SUMMARY

This article describes some windows attributes related to a Report Preview Window. The tasks described in this article are available as commands in Microsoft FoxPro version 2.6 for Windows as well as versions 3.0 and 3.0b. This article describes how to disable the Minimize and Maximize properties of the Report Preview window using API routines.

MORE INFORMATION

It is possible to control whether a Report Preview Window property can be changed. The minimize/maximize attributes can be controlled by using some API calls. In this article, the customized API routine was written using Microsoft Visual C++ 4.0 to change the attribute of Visual FoxPro Preview Window properties. As a default, the Visual FoxPro Report Preview Window can be minimized or maximized by pressing the upper right-hand corner of the preview window. Since the Report Preview Window is a system-generated window, you need to call API routines to handle the Preview Window property.

The following sample program illustrates the contents of the .DLL file written in Microsoft Visual C++ 4.0. It shows a way to change the attribute of Visual FoxPro Report Preview Window successfully through the Win32 SDK.

NOTE: This sample program illustrates many Microsoft Visual C++ commands. The use of these commands is beyond the scope of Microsoft FoxPro Product Support. Users with substantial experience using API routines should be able to write the following sample .DLL file. For this sample .DLL file to work, you need a .DEF file to export the disable function.

Sample Program (DLL)

   #include <windows.h>

   #define IDS_MEMVIEWCLASS        11005

   BOOL APIENTRY DllMain(HANDLE hInst, DWORD ul_reason_being_called, LPVOID
   lpReserved)
   {
       return 1;
           UNREFERENCED_PARAMETER(hInst);
           UNREFERENCED_PARAMETER(ul_reason_being_called);
           UNREFERENCED_PARAMETER(lpReserved);
   }

   void APIENTRY disable(char *title, char *header)
   {
         HWND  hWnd,    // a handle for parent window
            hChild;     // a handle for child window

      // attempt to find the parent window of report preview window
        hWnd = FindWindow(NULL, title);

        char title1[75];

        // attempt to look for first child window
        hChild = GetWindow(hWnd,GW_CHILD);
        while (hChild != 0) {
           hWnd = hChild;
         // look for first sibling of child window
         hChild = GetWindow(hWnd,GW_HWNDNEXT);
         while (hChild != 0) {
            hWnd = hChild;
            GetWindowText(hWnd,title1,75);
            if (strcmp(title1,header) == 0) {
               DWORD L;
         // disable minimize and maximize button of preview window
               L = GetWindowLong(hChild, GWL_STYLE);
               L = L & ~(WS_MINIMIZEBOX);
               L = L & ~(WS_MAXIMIZEBOX);
               SetWindowLong(hChild,GWL_STYLE,L);
               // redraw the preview window
               SetWindowPos(hChild,NULL,0,0,0,0,
   SWP_DRAWFRAME|SWP_NOZORDER|SWP_NOMOVE|SWP_NOSIZE);
               return;
            }
            hChild = GetWindow(hWnd,GW_HWNDNEXT);
         }
         hChild = GetWindow(hWnd,GW_CHILD);
        }
      return;
   }

Sample Program (FoxPro)

   REPORT FORM student PREVIEW NOWAIT
   DECLARE integer disable IN disable.DLL  string, string
   FoxHWND = disable("Microsoft Visual FoxPro",;
      "Report Designer - student.frx - Page 1")

Sample Program (Notes)

• To create a .DLL file in Visual C++, please refer to a Help file in Microsoft Visual C++ 4.0.
• Make a note that the Disable.dll should be in the same directory as your project, or should be in the path of the Windows Win32 directory.

  The API function needs two parameters. The first parameter is the main project window that is usually a Visual FoxPro window. The caption must be identical. The second parameter is the caption of preview window where you want to disable the minimize/maximize buttons. If, for any reason, the program does not work properly, you need to check the captions of those two windows prior to running the program.