FIX: Print Preview Scroll Bar Disappears after Zoom In, Zoom Out

RESOLUTION

There is no easy workaround, but an approximate workaround below allows the user to scroll through pages using the up/down arrows of the scroll bars, but the "thumbs" will not appear proportionally.

Derive a class from CPreviewView (you need to include Afxpriv.h) and override PositionPage(). You can use code similar to the following:

Sample Code

   //MyPreviewView.h

   #include <afxpriv.h>

   class CMyPreviewView : public CPreviewView
   {

   private:
      DECLARE_DYNCREATE(CMyPreviewView)

   protected:
      virtual void PositionPage(UINT nPage);
   };

   =======================================================

   //MyPreviewView.cpp
   #include "stdafx.h"
   #include "MyPreviewView.h"

   IMPLEMENT_DYNCREATE(CMyPreviewView, CPreviewView )

   /////////////////////////////////////////////////////////////////// 
   void  CMyPreviewView::PositionPage(UINT nPage)
   {
      CPreviewView::PositionPage(nPage);

      if(m_nZoomState == ZOOM_OUT)
         EnableScrollBarCtrl(SB_VERT, TRUE);
   }
   ================================================================
				

Add OnFilePrintPreview() to your application's view class, and put your CPreviewView-derived class name in the call to DoPrintPreview:

Sample Code

   void CScribbleView::OnFilePrintPreview()
   {
      // In derived classes, implement special window handling here.
      // Be sure to Unhook Frame Window close if hooked.
      // Must not create this on the frame. Must outlive this function.

      CPrintPreviewState* pState = new CPrintPreviewState;

      // DoPrintPreview's return value does not necessarily indicate that
      // Print Preview succeeded or failed, but rather what actions are
      // necessary at this point. If DoPrintPreview returns TRUE, it means
      // that OnEndPrintPreview will be (or has already been) called and
      // the pState structure will be/has been deleted.
      // If DoPrintPreview returns FALSE, it means that OnEndPrintPreview
      // WILL NOT be called and that cleanup, including deleting pState,
      // must be done here.

      if (!DoPrintPreview(AFX_IDD_PREVIEW_TOOLBAR, this,
         RUNTIME_CLASS(CMyPreviewView), pState))
      {
         // In derived classes, reverse special window handling here for
         // Preview failure case.

         TRACE0("Error: DoPrintPreview failed.\n");
         AfxMessageBox(AFX_IDP_COMMAND_FAILURE);
         delete pState; // Preview failed to initialize, delete State now.
      }
   }
   ==============================================================
				

Change your view's message map so that it has OnFilePrintPreview() in it:

   ON_COMMAND(ID_FILE_PRINT_PREVIEW, OnFilePrintPreview)
				

Add the appropriate #include to your applications's view class, such as:

   #include "MyPreviewView.h"
				

Add the following line to your view class's header file:

   void OnFilePrintPreview();