SDI程序中，如何在主框架上切换不同的视图

long CMainFrame::OnOutbarNotify(WPARAM wParam, LPARAM lParam)
{
switch (wParam)
{
case NM_OB_ITEMCLICK:
// cast the lParam to an integer to get the clicked item
{
int flag=wndBar.GetFolderData(); if(flag==0)//判断是否为第一个Folder
{
int index = (int) lParam;
if(index==0)       //响应第一个按钮
{
wndSplitter.DeleteView(0,1);
wndSplitter.CreateView(0,1,RUNTIME_CLASS(CTestView),CSize(0,70),NULL); 
wndSplitter.RecalcLayout();
} 
if(index==1)       //响应第二个按钮
{
wndSplitter.DeleteView(0,1);
           wndSplitter.CreateView(0,1,RUNTIME_CLASS(CTestView2),CSize(0,70),NULL);
                     wndSplitter.RecalcLayout();
}
if(index==2)       //响应第三个按钮
{
wndSplitter.DeleteView(0,1);
                     wndSplitter.CreateView(0,1,RUNTIME_CLASS(CTestView3),CSize(0,70),NULL);
                     wndSplitter.RecalcLayout();
}
}
else if(flag==1)//判断是否为第二个Folder
{
int index = (int) lParam;
if(index==0)       //响应第一个按钮
{
wndSplitter.DeleteView(0,1);
wndSplitter.CreateView(0,1,RUNTIME_CLASS(CTestView4),CSize(0,70),NULL);
                     wndSplitter.RecalcLayout();
}
if(index==1)
{
wndSplitter.DeleteView(0,1);
wndSplitter.CreateView(0,1,RUNTIME_CLASS(CTestView5),CSize(0,70),NULL);
                     wndSplitter.RecalcLayout();
}
if(index==2)
{
wndSplitter.DeleteView(0,1);
wndSplitter.CreateView(0,1,RUNTIME_CLASS(CTestView6),CSize(0,70),NULL);
                     wndSplitter.RecalcLayout();
}
if(index==3)
{
wndSplitter.DeleteView(0,1);
wndSplitter.CreateView(0,1,RUNTIME_CLASS(CTestView7),CSize(0,70),NULL);
                     wndSplitter.RecalcLayout();
}
}
else if(flag==2)//判断是否为第三个Folder
{
int index = (int) lParam;
if(index==0)       //响应第一个按钮
{
wndSplitter.DeleteView(0,1);
wndSplitter.CreateView(0,1,RUNTIME_CLASS(CTestView8),CSize(0,70),NULL);
                     wndSplitter.RecalcLayout();
}
}
}
return 0;

case NM_OB_ONLABELENDEDIT:
// cast the lParam to an OUTBAR_INFO * struct; it will contain info about the edited item
// return 1 to do the change and 0 to cancel it
{
OUTBAR_INFO * pOI = (OUTBAR_INFO *) lParam;
TRACE2("Editing item %d, new text:%s\n", pOI->index, pOI->cText);
}
return 1;

case NM_OB_ONGROUPENDEDIT:
// cast the lParam to an OUTBAR_INFO * struct; it will contain info about the edited folder
// return 1 to do the change and 0 to cancel it
{
OUTBAR_INFO * pOI = (OUTBAR_INFO *) lParam;
TRACE2("Editing folder %d, new text:%s\n", pOI->index, pOI->cText);
}
return 1;

case NM_OB_DRAGITEM:
// cast the lParam to an OUTBAR_INFO * struct; it will contain info about the dragged items
// return 1 to do the change and 0 to cancel it
{
OUTBAR_INFO * pOI = (OUTBAR_INFO *) lParam;
TRACE2("Drag item %d at position %d\n", pOI->iDragFrom, pOI->iDragTo);
}
return 1;
}
return 0;
}