VC实现自绘图形输出到bmp文件

在用vc做程序时候，经常需要把输出的文本和图形保存到位图文件，当然可以有现成的控件来实现,但总不能如自己所愿，还是自己动手写吧！如下图：



一、实现方法

　　要把文本和图形保存到位图文件，只要对掌握位图结构有一定的了解，一切都ok呢。先必须要创建内存设备环境，然后内存设备环境创建的DIB区域，别忘了还要创建个CBitmap对象，CBitmap对象必须和DIB区域关联起来，把CBitmap对象选择到当前设备环境，然后在当前设备环境输出文本和图形就可以了。

二、具体实现代码如下

void CTestSaveBmpView::SaveAsBmp(CString filename){//定义图形大小int iWidth = 800;int iHeight = 600;int iPixel = 16;//图形格式参数LPBITMAPINFO lpbmih = new BITMAPINFO;lpbmih->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);lpbmih->bmiHeader.biWidth = iWidth;lpbmih->bmiHeader.biHeight = iHeight;lpbmih->bmiHeader.biPlanes = 1;lpbmih->bmiHeader.biBitCount = iPixel;lpbmih->bmiHeader.biCompression = BI_RGB;lpbmih->bmiHeader.biSizeImage = 0;lpbmih->bmiHeader.biXPelsPerMeter = 0;lpbmih->bmiHeader.biYPelsPerMeter = 0;lpbmih->bmiHeader.biClrUsed = 0;lpbmih->bmiHeader.biClrImportant = 0;//创建位图数据HDC hdc,hdcMem;HBITMAP hBitMap = NULL;CBitmap *pBitMap = NULL;CDC *pMemDC = NULL;BYTE *pBits;hdc = CreateIC(TEXT("DISPLAY"),NULL,NULL,NULL);hdcMem = CreateCompatibleDC(hdc);hBitMap = CreateDIBSection(hdcMem,lpbmih,DIB_PAL_COLORS,(void **)&pBits,NULL,0);pBitMap = new CBitmap;pBitMap->Attach(hBitMap);pMemDC = new CDC;pMemDC->Attach(hdcMem);pMemDC->SelectObject(pBitMap);//CRect rc(0,0,iWidth,iHeight);pMemDC->SetBkMode(TRANSPARENT);//添加自绘图形 DrawCurve(pMemDC,rc);//保存到文件并创建位图结构BITMAPFILEHEADER bmfh;ZeroMemory(&bmfh,sizeof(BITMAPFILEHEADER));*((char *)&bmfh.bfType) = ''B'';*(((char *)&bmfh.bfType) + 1) = ''M'';bmfh.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER);bmfh.bfSize = bmfh.bfOffBits + (iWidth * iHeight) * iPixel / 8;TCHAR szBMPFileName[128];int iBMPBytes = iWidth * iHeight * iPixel / 8;strcpy(szBMPFileName,filename);CFile file;if(file.Open(szBMPFileName,CFile::modeWrite | CFile::modeCreate)){file.Write(&bmfh,sizeof(BITMAPFILEHEADER));file.Write(&(lpbmih->bmiHeader),sizeof(BITMAPINFOHEADER));file.Write(pBits,iBMPBytes);file.Close();}pMemDC->DeleteDC();delete pMemDC; pMemDC = NULL;delete pBitMap; pBitMap = NULL;delete lpbmih; lpbmih = NULL;}//输出文本和图形void CTestSaveBmpView::DrawCurve(CDC *pDC, CRect rcClient){//页面背景色CBrush brushCtl;brushCtl.CreateSolidBrush(RGB(255,255,255));pDC->Rectangle(rcClient);pDC->FillRect(rcClient,&brushCtl) ;brushCtl.DeleteObject();CPen pen;pen.CreatePen(PS_SOLID, 1, RGB(255,0,0));CPen *oldPen = pDC->SelectObject(&pen); double xMin = 10.00f, xMax = 100.00f;double yMin = 10.00f, yMax = 200.00f;double dbX1 = (xMax- xMin)/100 + xMin;double dbY1 = 600/dbX1 ;for (int i=1; i<100; i++) //曲线{double dbX2 = (xMax- xMin)*i/100 + xMin;double dbY2 = 600/dbX2 ;pDC->MoveTo(int(rcClient.left+(dbX1 - xMin)*rcClient.Width()/(xMax- xMin)), int(rcClient.bottom-(dbY1- yMin)*rcClient.Height()/(yMax- yMin)));pDC->LineTo(int(rcClient.left+(dbX2 - xMin)*rcClient.Width()/(xMax- xMin)), int(rcClient.bottom-(dbY2- yMin)*rcClient.Height()/(yMax- yMin))); dbX1=dbX2;dbY1=dbY2;}pDC->SelectObject(oldPen); pen.DeleteObject();oldPen = NULL;}//保存的实现void CTestSaveBmpView::OnRButtonDown(UINT nFlags, CPoint point) {CFileDialog dlg(false,NULL,NULL,OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT,"位图文件(*.bmp)|*.bmp|",NULL);if (dlg.DoModal()!= IDOK) return;CString filename = dlg.GetFileName() + ".bmp";SaveAsBmp(filename); CView::OnRButtonDown(nFlags, point);}