BitBlt 贴图后只剩黑白色

[woshilaoshiren789]

void CMapData::ReSize(int w,int h) 
{
	if(w==Width&&h==Height)
		return;
	CDC myDC ;
	CBitmap myMap ,*oldmyMap;
	CBrush b; 
	int ww = w>Width?w:Width ;
	int hh = h>Height?h:Height ;
	myDC.CreateCompatibleDC(&pDC) ;	
	myMap.CreateCompatibleBitmap(&pDC,ww,hh) ;
	oldmyMap = myDC.SelectObject(&myMap) ;

	b.CreateSolidBrush(RGB(0,0,255)) ;
	myDC.FillRect(CRect(0,0,ww,hh),&b) ;
	myDC.BitBlt(0,0,Width,Height,&pDC,0,0,SRCCOPY) ;/////备份当前绘图

	
	pDC.SelectObject(oldmap) ;
	map.DeleteObject() ;

	map.CreateCompatibleBitmap(&pDC,w,h) ;
	oldmap = pDC.SelectObject(&map) ;
	
	pDC.BitBlt(0,0,w,h,&myDC,0,0,SRCCOPY) ;///恢复到新尺寸的位图；	

	Width = w ;
	Height = h ;
	myDC.SelectObject(oldmyMap) ;
	myDC.DeleteDC() ;
	myMap.DeleteObject() ;
	b.DeleteObject() ;

	oldPoint = newPoint =CPoint(-1,-1) ;

}

[schlafenhamster]

virtual BOOL CreateCompatibleDC( CDC* pDC );

Return Value

Nonzero if the function is successful; otherwise 0.

Parameters

pDC

A pointer to a device context. If pDC is NULL, the function creates a memory device context that is compatible with the system display.

Remarks

Creates a memory device context that is compatible with the device specified by pDC. A memory device context is a block of memory that represents a display surface. It can be used to prepare images in memory before copying them to the actual device surface of the compatible device.

When a memory device context is created, GDI automatically selects a 1-by-1 monochrome stock bitmap for it. GDI output functions can be used with a memory device context only if a bitmap has been created and selected into that context.

When a memory device context is created, GDI automatically selects a 1-by-1 monochrome stock bitmap for it.

[woshilaoshiren789]

没看懂，你是说我不用重新选一个MyMap到MyDC吗？

[schlafenhamster]

如

void CLeftView::OnDraw(CDC* pDC)
{
	CVC60Doc* pDoc = GetDocument();
	ASSERT_VALID(pDoc);
//
	if(pDoc->GetLeftBitmap())//m_hBmpLeft)
	{// not client rect only !
		SIZE sz=GetTotalSize();
		sz.cx-=10;//gap
		sz.cy-=10;
		CDC memDC;
		memDC.CreateCompatibleDC(pDC);
		HBITMAP hOldBitmap = (HBITMAP)memDC.SelectObject(pDoc->GetLeftBitmap());//m_hBmpLeft);
		pDC->BitBlt(4, 4, sz.cx, sz.cy, &memDC, 0, 0, SRCCOPY);// may bigger then client
		memDC.SelectObject(hOldBitmap);
	}
	else
	{
		pDC->TextOut(10, 10, "Open a 24bits bitmap!");
	}
}

void CLeftView::OnDraw(CDC* pDC)// 这个dc是彩色 DC CDC memDC; memDC.CreateCompatibleDC(pDC); // 这个dc是彩色 DC

[woshilaoshiren789]

请教各位大婶，代码中没发现有什么问题啊，粘贴后只有黑白色，原图中的彩色没有了。

[schlafenhamster]

CClientDC myDC(this) ;

[woshilaoshiren789]

该函数只是想实现当前pDC上的map的大小。其中pDC，map都是初始化没问题的。

[tingtings324]

想问问 你那个pDC 是全局的吗 也是个memdc吗 我也遇到这个了 兄台怎么破的？