WCF 绘图问题，如何实现在背景图上绘制坐标

新月星雪 2017-06-20 03:40:03

如图所示，我需要将黑色背景部分换成位图。现在遇到问题，当加入位图后，无法显示图上的定位坐标。



void CMappingView::OnDraw(CDC* pDC)

{

	/// 获取当前窗体矩形

	CRect rect;

	GetClientRect(rect);



	/// 首先定义一个显示设备对象

	CDC MemDC;

	MemDC.CreateCompatibleDC(NULL);



	/// 定义一个位图对象

	CBitmap MemBitmap;

	/// 创建位图大小

	MemBitmap.CreateCompatibleBitmap(pDC, rect.Width(), rect.Height());

	CBitmap *pOldBit = MemDC.SelectObject(&MemBitmap);



	/// 画XY轴坐标

	DrawCoordinate(&MemDC);	



	/// 将内存中的图像拷贝到显存中

	pDC->BitBlt(rect.left, rect.top, rect.Width(), rect.Height(), &MemDC, rect.left, rect.top, SRCCOPY);



	/// 画XY轴背景图

	DrawCameraImage(pDC, &MemDC);



	/// 画定位点位

	DrawVisualization(&MemDC);

	//pDC->BitBlt(rect.left, rect.top, rect.Width(), rect.Height(), &MemDC, rect.left, rect.top, SRCCOPY);



	/// 清空内存

	MemDC.SelectObject(pOldBit);

	MemBitmap.DeleteObject();

	MemDC.DeleteDC();

}



void CMappingView::DrawCameraImage(CDC *pDC, CDC *memDC)

{

	CMainFrame *p = (CMainFrame*)AfxGetMainWnd();

	CMappingDoc *pDoc = (CMappingDoc*)GetDocument();



	HBITMAP hbm = (HBITMAP)::LoadImage(AfxGetInstanceHandle(),

						"C:\\Windows\\Image_0619140611.bmp",

						IMAGE_BITMAP,

						0,0,

						LR_LOADFROMFILE | LR_CREATEDIBSECTION );

	if(hbm == NULL)

	{

		return;

	}

	CBitmap* pBitmap = CBitmap::FromHandle(hbm);

	BITMAP bmpInfo;

	pBitmap->GetBitmap(&bmpInfo);

	CBitmap *pOldBitmap = pDC->SelectObject(pBitmap);



	memDC->SelectObject(pBitmap);



	CRect rect;

	GetClientRect(rect);



	raxis.left = rect.left + 60;

	raxis.right = rect.right - 20;

	raxis.top = rect.top + 20;

	raxis.bottom = rect.bottom - 60;



    int width = raxis.right - raxis.left + 1;

	width = width % 4 ? (width + (4 - width % 4)) : width;

	raxis.right = raxis.left + width - 1;



	pDC->StretchBlt(

		r.left, 

		r.top, 

		r.Width(), 

		r.Height(), 

		memDC, 

		0,0,

		bmpInfo.bmWidth, 

		bmpInfo.bmHeight, 

		SRCCOPY);



	pBitmap->DeleteObject();

}