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方法一： 在VS 2010中有一个类CMemDC， 在MFC下可解决绘图闪烁。
看看MSDN钟怎么说的：
CMemDC Class
A helper class for a memory device context. The memory device context supports offscreen drawing.
在库中的声明如下：
class CMemDC
{
public:
AFX_IMPORT_DATA static BOOL m_bUseMemoryDC;
CMemDC(CDC& dc, CWnd* pWnd);
CMemDC(CDC& dc, const CRect& rect);
virtual ~CMemDC();
CDC& GetDC() { return m_bMemDC ? m_dcMem : m_dc; }
BOOL IsMemDC() const { return m_bMemDC; }
BOOL IsVistaDC() const { return m_hBufferedPaint != NULL; }
protected:
CDC& m_dc;
BOOL m_bMemDC;
HANDLE m_hBufferedPaint;
CDC m_dcMem;
CBitmap m_bmp;
CBitmap* m_pOldBmp;
CRect m_rect;
};
使用方法:
// 1、响应WM_ERASEBKGND消息，返回FALSE，这样就不擦除背景了。 BOOL CDemoView::OnEraseBkgnd(CDC* pDC) { return FALSE; } // 2、在需要作图的地方使用CMemDC。
void CDemoView::OnDraw(CDC* pDC)
{
CGestureDemoDoc* pDoc = GetDocument();
ASSERT_VALID(pDoc);
CMemDC dcMem(*pDC, this);
CDC& dc = dcMem.GetDC();
//do anything with graphic object dc;
......
}
二： 网上有另外一种利用CMemDC继承CDC的方式如下：
#ifndef _MEMDC_H_
#define _MEMDC_H_
//
// CMemDC - memory DC
//
// Author: Keith Rule
// Email: keithr@europa.com
// Copyright 1996-1999, Keith Rule
//
// You may freely use or modify this code provided this
// Copyright is included in all derived versions.
//
// History - 10/3/97 Fixed scrolling bug.
// Added print support. - KR
//
// 11/3/99 Fixed most common complaint. Added
// background color fill. - KR
//
// 11/3/99 Added support for mapping modes other than
// MM_TEXT as suggested by Lee Sang Hun. - KR
//
// This class implements a memory Device Context which allows
// flicker free drawing.
class CMemDC : public CDC {
protected:
CBitmap m_bitmap; // Offscreen bitmap
CBitmap* m_oldBitmap; // bitmap originally found in CMemDC
CDC* m_pDC; // Saves CDC passed in constructor
CRect m_rect; // Rectangle of drawing area.
BOOL m_bMemDC; // TRUE if CDC really is a Memory DC.
void Construct(CDC* pDC)
{
ASSERT(pDC != NULL);
// Some initialization
m_pDC = pDC;
m_oldBitmap = NULL;
m_bMemDC = !pDC->IsPrinting();
if (m_bMemDC) {
// Create a Memory DC
CreateCompatibleDC(pDC);
pDC->LPtoDP(&m_rect);
m_bitmap.CreateCompatibleBitmap(pDC, m_rect.Width(), m_rect.Height());
m_oldBitmap = SelectObject(&m_bitmap);
SetMapMode(pDC->GetMapMode());
pDC->DPtoLP(&m_rect);
SetWindowOrg(m_rect.left, m_rect.top);
} else {
// Make a copy of the relevent parts of the current DC for printing
m_bPrinting = pDC->m_bPrinting;
m_hDC = pDC->m_hDC;
m_hAttribDC = pDC->m_hAttribDC;
}
// Fill background
FillSolidRect(m_rect, pDC->GetBkColor());
}
// TRK begin
public:
CMemDC(CDC* pDC ) : CDC() { pDC->GetClipBox(&m_rect); Construct(pDC); }
CMemDC(CDC* pDC, const RECT& rect) : CDC() { m_rect = rect ; Construct(pDC); }
// TRK end
virtual ~CMemDC()
{
if (m_bMemDC) {
// Copy the offscreen bitmap onto the screen.
m_pDC->BitBlt(m_rect.left, m_rect.top, m_rect.Width(), m_rect.Height(),
this, m_rect.left, m_rect.top, SRCCOPY);
//Swap back the original bitmap.
SelectObject(m_oldBitmap);
} 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 usage as a pointer
CMemDC* operator->()
{
return this;
}
// Allow usage as a pointer
operator CMemDC*()
{
return this;
}
};
#endif
使用方法类同前面所述：
/// // How to use: /// // 1、响应WM_ERASEBKGND消息，返回FALSE，这样就不擦除背景了。 BOOL CDemoView::OnEraseBkgnd(CDC* pDC) { return FALSE; } /// // 2、在需要作图的地方使用CMemDC。 void CDemoView::OnDraw(CDC* pDC) { CFont font; font.CreateFontIndirect(&m_lf); CMemDC pMemDC(pDC); CFont* oldfont = pMemDC->SelectObject(&font); //..Draw something here. pMemDC->SelectObject(oldfont); } /// // 别忘了加include头文件！ /// 来源：http://blog.csdn.net/mplus/article/details/6131526