封装MemDC

#include "StdAfx.h"
#include "MemDC.h"




MemDC::MemDC(void)
{
m_size.cx=m_size.cy=0;
}




MemDC::~MemDC(void)
{
DeleteDC();
}


MemDC::MemDC(UINT nBitmapID,CDC *pDC)
{
LoadBitmap(nBitmapID,pDC);
}
MemDC::MemDC(LPCWSTR szBitmapFile,CDC *pDC)
{
LoadBitmap(szBitmapFile,pDC);
}
MemDC::MemDC(int cx,int cy,CDC *pDC)
{
Create(cx,cy,pDC);
}


BOOL MemDC::DeleteDC()
{
if(!GetSafeHdc())
return TRUE;
CBitmap* pBitmap=GetCurrentBitmap();
pBitmap->DeleteObject();
return CDC::DeleteDC();
}
BOOL MemDC::Create(int cx,int cy,CDC*pDC)
{
CBitmap bitmap;
bitmap.CreateCompatibleBitmap(pDC,cx,cy);
m_size.cx=cx;
m_size.cy=cy;
SelectObject(bitmap);;
return TRUE;
}
BOOL MemDC::LoadBitmap(LPCWSTR szBitmapFile,CDC*pDC)
{
HBITMAP hBitmap=(HBITMAP)LoadImage(AfxGetInstanceHandle(),szBitmapFile,IMAGE_BITMAP,0,0,LR_LOADFROMFILE);
BITMAP bm;
GetObject(hBitmap,sizeof(bm),&bm);
m_size.cx=bm.bmWidth;
m_size.cy=bm.bmHeight;
CreateCompatibleDC(pDC);
SelectObject(hBitmap);
return TRUE;


}
BOOL MemDC::LoadBitmap(UINT nBitmapID,CDC*pDC)
{
CBitmap bitmap;
bitmap.LoadBitmap(nBitmapID);
BITMAP bm;
bitmap.GetBitmap(&bm);
m_size.cx=bm.bmWidth;
m_size.cy=bm.bmHeight;
CreateCompatibleDC(pDC);
SelectObject(bitmap);
return TRUE;
}
int MemDC::WidthX()
{
return m_size.cx;
}
int MemDC::HeightY()
{
return m_size.cy;
}