C / C++ / MFC

WORD CascadeWindows(
  HWND hwndParent,     // handle to parent window
  UINT wHow,           // types of windows not to arrange
  CONST RECT *lpRect,  // rectangle to arrange windows in
  UINT cKids,          // number of windows to arrange
  const HWND *lpKids   // array of window handles
);

1. Create the app (mine is called MDIFormViewTest).
   
   
2. Create the dialog template resource. (I created two, IDD_DIALOG1 and IDD_DIALOG2).
   
   
3. Change template's Style property to Child
   
   
4. Create a CFormView derived class based on the template. Mine are CFormView1 and CFormView2.
   
   
5. Create the menu option (using the MDI menu)
   
   
6. Define a CMultiDocTemplate member variable in the document for each form view. For the two form views in my demo, here are their document template pointers.
   

   class CMDIFormViewTestDoc : public CDocument
   {
    ...
    CMultiDocTemplate* m_pFormView1Template;
    CMultiDocTemplate* m_pFormView2Template;
    ...
   }

   
   
   
7. Add the following include directive to the document's file for the childfrme.h and your formviews
   

   #include "ChildFrm.h"
   #include "FormView1.h"
   #include "FormView2.h"

   
   
   
8. Create and add the template to the application's doc manager in the document's constructor
   

   CMDIFormViewTestDoc::CMDIFormViewTestDoc()
   {
    CWinApp* pApp = AfxGetApp();
    ASSERT(pApp);
    if (pApp)
    {
      m_pFormView1Template = new CMultiDocTemplate(IDR_MDIFormViewTestTYPE,
       RUNTIME_CLASS(CMDIFormViewTestDoc),
       RUNTIME_CLASS(CChildFrame), // custom MDI child frame
       RUNTIME_CLASS(CFormView1));
      pApp->AddDocTemplate(m_pFormView1Template);
   
      m_pFormView2Template = new CMultiDocTemplate(IDR_MDIFormViewTestTYPE,
       RUNTIME_CLASS(CMDIFormViewTestDoc),
       RUNTIME_CLASS(CChildFrame), // custom MDI child frame
       RUNTIME_CLASS(CFormView2));
      pApp->AddDocTemplate(m_pFormView2Template);
     }
   }

   
   
   
   
9. Define the following function in your document class. This function will either create the view if not present or activate it (bring it to the foreground).
   

   void CMDIFormViewTestDoc ::CreateOrActivateFrame(CDocTemplate* pTemplate, CRuntimeClass* pViewClass)
   {                
     // Search through document's attatched views
     CView* pView;
     POSITION pos = GetFirstViewPosition();
     while (pos != NULL)
     {
      pView = GetNextView(pos);
      // If the kind found matches kind passed as parameter, activate it
      if (pView->IsKindOf(pViewClass))
      {
       pView->GetParentFrame()->ActivateFrame(SW_RESTORE);
       return;
      }                                                                 
     }		       
     // Did not find the correct active, so create and initialize one
     CFrameWnd* pFrame = pTemplate->CreateNewFrame(this, NULL);
     ASSERT(pFrame);
     pTemplate->InitialUpdateFrame(pFrame, this);
   }

   
   
   
10. Add an event handler to the document for each form view menu entries and call the CreateOrActiveFrame function. Here are the two for my demo.
    

    void CMDIFormViewTestDoc::OnFormviewsView1()
    {
     CreateOrActivateFrame(m_pFormView1Template, RUNTIME_CLASS(CFormView1));
    }
    
    void CMDIFormViewTestDoc::OnFormviewsView2()
    {
     CreateOrActivateFrame(m_pFormView2Template, RUNTIME_CLASS(CFormView2));
    }
    

    
    
    
    Cheers,
    Tom Archer
    Author, Inside C#
    
    A total abstainer is one who abstains from everything but abstention, and especially from inactivity in the affairs of others.

class __declspec(dllexport) CPacket
{
protected:
  static long m_counter;
};

long CPacket::m_counter = 1;

class AFX_EXT_CLASS CPacket
{
protected:
  static long m_counter;
};

long CPacket::m_counter = 1;