C++ MFC,内存上下文中的绘图文本(打印)
我遇到了一个问题-我需要在内存中创建一个位图,在其中绘制一些文本,并将其保存为BMP文件,然后用物理打印机打印出位图。我可以在对话框窗口上下文中绘制此图形-效果很好。但当我尝试在打印机上下文中绘制相同的图形时,文本不会出现。我真的不明白为什么会这样。请帮帮我,伙计们。提前谢谢。代码如下:C++ MFC,内存上下文中的绘图文本(打印),c++,mfc,drawtext,C++,Mfc,Drawtext,我遇到了一个问题-我需要在内存中创建一个位图,在其中绘制一些文本,并将其保存为BMP文件,然后用物理打印机打印出位图。我可以在对话框窗口上下文中绘制此图形-效果很好。但当我尝试在打印机上下文中绘制相同的图形时,文本不会出现。我真的不明白为什么会这样。请帮帮我,伙计们。提前谢谢。代码如下: void CMy2Dlg::OnButton1() { // TODO: Add your control notification handler code here CPrintDialo
void CMy2Dlg::OnButton1()
{
// TODO: Add your control notification handler code here
CPrintDialog pd(false);
if (pd.DoModal()==IDOK)
{
CDC PrintDC;
HDC hdc = pd.CreatePrinterDC();
PrintDC.Attach(hdc);
DOCINFO infStru;
::ZeroMemory (&infStru, sizeof (DOCINFO));
CString title="Print test";
infStru.cbSize = sizeof (DOCINFO);
infStru.lpszDocName=title;
infStru.lpszOutput=NULL;
PrintDC.StartDoc(&infStru);
PrintDC.StartPage();
{
CRect r, r2;
CBitmap memBMP, * pOldBitmap;
CPaintDC dc(this);
CDC memDC, *pDC = &memDC;
CFont font, * pOldFont;
int width = 2000;
int height = 1500;
int textwidth = 300;
int textheight = 150;
int oldMapMode = 0;
int oldbkmode = 0;
int i, j;
LOGFONT logFont, lf;
COLORREF oldTextColor;
memset(&logFont, 0, sizeof(logFont));
logFont.lfHeight = 16;
logFont.lfWidth = 0;
logFont.lfEscapement = 0;
logFont.lfOrientation = 0;
logFont.lfWeight = FW_NORMAL;
logFont.lfItalic = FALSE;
logFont.lfUnderline = FALSE;
logFont.lfStrikeOut = 0;
logFont.lfCharSet = ANSI_CHARSET;
logFont.lfOutPrecision = OUT_DEFAULT_PRECIS;
logFont.lfClipPrecision = CLIP_DEFAULT_PRECIS;
logFont.lfQuality = DEFAULT_QUALITY;
logFont.lfPitchAndFamily = DEFAULT_PITCH | FF_SWISS;
strcpy(logFont.lfFaceName, "Arial");
if(memDC.CreateCompatibleDC(&PrintDC)) {
if (memBMP.CreateCompatibleBitmap(&PrintDC, width, height)) {
pOldBitmap = pDC->SelectObject(&memBMP);
pDC->FillSolidRect(0, 0, width, height, RGB(200, 200, 200));
oldTextColor = pDC->SetTextColor(RGB(255,0,0));
oldMapMode = pDC->SetMapMode(MM_LOMETRIC);
oldbkmode = pDC->SetBkMode(TRANSPARENT);
lf = logFont;
lf.lfHeight = -MulDiv(lf.lfHeight, GetDeviceCaps(pDC->GetSafeHdc(), LOGPIXELSY), 72);
//lf.lfHeight = 100;
font.CreateFontIndirect(&lf);
pOldFont = pDC->SelectObject(&font);
r.left = 10;
r.top = 10;
r.right = r.left + textwidth;
r.bottom = r.top + textheight;
r.top *= -1;
r.bottom *= -1;
pDC->MoveTo(r.left, r.top);
pDC->LineTo(r.right, r.top);
pDC->LineTo(r.right, r.bottom);
pDC->LineTo(r.left, r.bottom);
pDC->LineTo(r.left, r.top);
pDC->DrawText("qwerty", &r, DT_CENTER | DT_SINGLELINE | DT_VCENTER);
pDC->SetMapMode(oldMapMode);
pDC->SetTextColor(oldTextColor);
pDC->SetBkMode(oldbkmode);
PrintDC.BitBlt(10, 10, width, height, pDC, 0, 0, SRCCOPY);
pDC->SelectObject(pOldBitmap);
pDC->SelectObject(pOldFont);
font.DeleteObject();
memBMP.DeleteObject();
pDC->DeleteDC();
}
}
}
PrintDC.EndPage();
PrintDC.EndDoc();
PrintDC.Detach();
DeleteDC(hdc);
}
}
如果在内存DC上使用SetMapMode(MM_LOMETRIC)
,则在使用BitBlt
复制到打印机/显示DC时,内存DC必须颠倒绘制。宽度/高度也必须调整。只需使用默认的映射模式(MM\u TEXT
)。在打印机DC上绘图时,如果需要特定的测量单位,请使用SetMapMode(MM_LOMETRIC)
void CMy2Dlg::OnButton1()
{
//create the bitmap
int w = 600, h = 400;
CClientDC dc(this);
CBitmap bmp;
CDC memdc;
memdc.CreateCompatibleDC(&dc);
bmp.CreateCompatibleBitmap(&dc, w, h);
auto oldbmp = memdc.SelectObject(bmp);
//draw on bitmap
memdc.FillSolidRect(0, 0, w, h, RGB(200, 200, 200));
memdc.SetTextColor(RGB(255, 0, 0));
CRect rc(0, 0, w, h);
memdc.DrawText(L"qwerty", &rc, 0);
dc.BitBlt(0, 0, w, h, &memdc, 0, 0, SRCCOPY);//optional: draw the bitmap on dialog
CPrintDialog pd(false);
if(pd.DoModal() == IDOK)
{
CDC PrintDC;
HDC hdc = pd.GetPrinterDC();
PrintDC.Attach(hdc);
DOCINFO docinfo = { sizeof(docinfo) };
docinfo.lpszDocName = L"Print test";
PrintDC.StartDoc(&docinfo);
PrintDC.StartPage();
PrintDC.BitBlt(0, 0, w, h, &memdc, 0, 0, SRCCOPY);
PrintDC.EndPage();
PrintDC.EndDoc();
}
dc.SelectObject(oldbmp);
}
矩形出现了吗?(顺便说一句,还有其他函数可以绘制矩形而不是绘制直线,但这是另一回事)你想用
r.top*=-1做什么;r、 底部*=-1代码>?不要把CPaintDC
放在那里。你的代码到处都是。创建一个单独的函数void paint(CDC*dc)
,该函数可以独立于打印对话框和位图进行绘制,然后将其打印到位图,然后单独打印位图。是的,它确实会出现。我需要负的垂直坐标值,因为使用的是MM_LOMETRIC贴图模式(-正x在右边;正y在上面)我知道代码很乱,但现在它没有打扰我,它只是一个快速而肮脏的实验。但感谢您的评论更改地图模式通常是在打印机dc上绘图时完成的。但是您在内存DC上使用的是SetMapMode(MM_LOMETRIC)
,这将使BitBlt
内存DC打开以显示/打印DC变得更加复杂。非常感谢!看来我需要的是用CClientDC绘图!