In the integration of the two different code, two different CMemDC class conflicts, now want to integrate them together, but only a memdc. H file, another memdc. CPP and memdc. H two files, I do not know how to integrate?
1, the first memdc. H

 # # ifndef _MEMDC_H_ 
The class CMemDC: public CDC 
{
Public: 

//the constructor sets up the memory DC 
CMemDC (pDC) CDC * : CDC () 
{
ASSERT (pDC!=NULL); 

M_pDC=pDC; 
M_pOldBitmap=NULL; 
M_bMemDC=! PDC - & gt; IsPrinting (); 

If (m_bMemDC)//Create a Memory DC 
{
PDC - & gt; GetClipBox (& amp; M_rect); 
CreateCompatibleDC (pDC); 
M_bitmap. CreateCompatibleBitmap (pDC, m_rect Width (), m_rect. Height ()); 
M_pOldBitmap=SelectObject (& amp; M_bitmap); 
SetWindowOrg (m_rect left, m_rect. Top); 
} 
The else//Make a copy of the relevent parts of the current DC for printing 
{
M_bPrinting=pDC - & gt; M_bPrinting; 
M_hDC=pDC - & gt; M_hDC; 
M_hAttribDC=pDC - & gt; M_hAttribDC; 
} 
} 

//Destructor copies the contents of the mem DC to the the original DC 
~ CMemDC () 
{
If (m_bMemDC) 
{
//Copy the offscreen bitmap onto the screen. 
M_pDC - & gt; BitBlt (m_rect m_rect. Left, top, m_rect. The Width (), m_rect. Height (), 
This, m_rect left, m_rect. Top SRCCOPY); 

//Swap back the the original bitmap. 
SelectObject (m_pOldBitmap); 
} else {
//All we need to do is replace the DC with an illegal value, 
//this keeps us from accidently deleting the handles associated with 
//the CDC that was passed to the constructor. 
M_hDC=m_hAttribDC=NULL; 
} 
} 

//Allow the usage as a pointer 
CMemDC * operator - & gt; () {return this; } 

//Allow the usage as a pointer 
Operator CMemDC * () {return this; } 

Private: 
CBitmap m_bitmap;//Offscreen bitmap 
CBitmap * m_pOldBitmap;//bitmap originally found in CMemDC 
The CDC * m_pDC;//Saves the CDC passed in the constructor 
CRect m_rect;//a Rectangle of drawing area. 
BOOL m_bMemDC;//TRUE if the CDC really is a Memory DC. 
}; 

# endif 

2, the second class is memdc. CPP and memdc h two files
Memdc. H

 
The class CMemDC: public CDC 
{
//Construction 
Public: 
CMemDC (UINT heigh, UINT width); 

//the Attributes 
Public: 

//Implementation 
Public: 
HBITMAP CloseMemDC (); 
Virtual ~ CMemDC (); 

Private: 
CBitmap m_bitmap; 
CBitmap * m_pOldBitmap; 
UINT m_bmpHeigh; 
UINT m_bmpWidth; 
}; 

Memdc. CPP

 # include "stdafx. H" 
# include "MemDC. H" 

# ifdef _DEBUG 
# define new DEBUG_NEW 
# undef THIS_FILE 
The static char THIS_FILE []=__FILE__; 
# endif 
CMemDC: : CMemDC (UINT width, UINT heigh) 
{
The CDC * pDC=CDC: : FromHandle (: : GetDC (GetDesktopWindow ())); 
ASSERT (pDC!=NULL); 
CreateCompatibleDC (pDC); 
M_bmpWidth=width; 
M_bmpHeigh=heigh; 
M_bitmap. CreateCompatibleBitmap (pDC, m_bmpWidth m_bmpHeigh); 
M_pOldBitmap=SelectObject (& amp; M_bitmap); 
: : ReleaseDC (GetDesktopWindow (), pDC - & gt; M_hDC); 
} 

CMemDC: : ~ CMemDC () 
{
SelectObject (m_pOldBitmap); 
M_bitmap. DeleteObject (); 
DeleteDC (); 
} 
HBITMAP CMemDC: : CloseMemDC () 
{
SelectObject (m_pOldBitmap); 
Return (HBITMAP) (m_bitmap Detach ()); 
} 

Now want to put the back of the MemDC class integrated into the first MemDC. H, how to deal with? Thank you very much!

CodePudding user response:

 class CMemDC: public CDC 
{
Public: 
CMemDC (UINT heigh, UINT width) 
{
The CDC * pDC=CDC: : FromHandle (: : GetDC (GetDesktopWindow ())); 
ASSERT (pDC!=NULL); 
CreateCompatibleDC (pDC); 
M_bmpWidth=width; 
M_bmpHeigh=heigh; 
M_bitmap. CreateCompatibleBitmap (pDC, m_bmpWidth m_bmpHeigh); 
M_pOldBitmap=SelectObject (& amp; M_bitmap); 
: : ReleaseDC (GetDesktopWindow (), pDC - & gt; M_hDC); 
M_nIndex=1; 
} 
//the constructor sets up the memory DC 
CMemDC (pDC) CDC * : CDC () 
{
ASSERT (pDC!=NULL); 

M_pDC=pDC; 
M_pOldBitmap=NULL; 
M_bMemDC=! PDC - & gt; IsPrinting (); 

If (m_bMemDC)//Create a Memory DC 
{
PDC - & gt; GetClipBox (& amp; M_rect); 
CreateCompatibleDC (pDC); 
M_bitmap. CreateCompatibleBitmap (pDC, m_rect Width (), m_rect. Height ()); 
M_pOldBitmap=SelectObject (& amp; M_bitmap); 
SetWindowOrg (m_rect left, m_rect. Top); 
} 
The else//Make a copy of the relevent parts of the current DC for printing 
{
M_bPrinting=pDC - & gt; M_bPrinting; 
M_hDC=pDC - & gt; M_hDC; 
M_hAttribDC=pDC - & gt; M_hAttribDC; 
} 
M_nIndex=0; 
} 

//Destructor copies the contents of the mem DC to the the original DC 
~ CMemDC () 
{
If (1==m_nIndex) 
{
SelectObject (m_pOldBitmap); 
M_bitmap. DeleteObject (); 
DeleteDC (); 
} 
The else {
If (m_bMemDC) 
{
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