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MFC初学者曲线一闪一闪的

发布时间: 2012-08-14 10:39:57 作者: rapoo

MFC菜鸟,曲线一闪一闪的
我已经用
class CMemDC : public CDC {
private:
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.
public:
CMemDC(CDC* pDC) : CDC(), m_oldBitmap(NULL), m_pDC(pDC)
{
ASSERT(m_pDC != NULL);// If you asserted here, you passed in a NULL CDC.

m_bMemDC = !pDC->IsPrinting();

if (m_bMemDC){
// Create a Memory DC
CreateCompatibleDC(pDC);
pDC->GetClipBox(&m_rect);
m_bitmap.CreateCompatibleBitmap(pDC, m_rect.Width(), m_rect.Height());
m_oldBitmap = SelectObject(&m_bitmap);
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;
}
}

~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;}
};

这样一个类去实现双缓存画图了,为什么图像还是一闪一闪的啊?

[解决办法]
亲 发错地方了 该发到MFC板块去
[解决办法]

探讨

我在cplot中是这样调用的
void clPlot::OnPaint()
{
CPaintDC dc(this); // device context for painting
CMemDC pdc(&dc); // non flickering painting
Draw(&pdc);// Do not call……

[解决办法]
一闪一闪的问题,有可能是你刷新太快。。就是调用Onpait函数太频繁

读书人网 >C++

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