积累的VC编程小技巧之视图

1.如何得到视图指针

[问题提出]
现在你有一个多线程的Demo,你想在多线程里处理视图指针里的函数,我们给这个函数起个名字:Put();该如何实现呢?
//有两种方法可以实现你的要求:
//1)第一种方法:
//要是多线程不是在App.cpp里出现,那么要在多线程的.cpp中加上extern CYourApp theApp;
//获得文档模板:
POSITION curTemplatePos = theApp.GetFirstDocTemplatePosition();
CDocTemplate *m_doc=theApp.GetNextDocTemplate(curTemplatePos);

//获得文档:
curTemplatePos=m_doc->GetFirstDocPosition();
CYourDoc *m_pdoc=(CA8Doc*)m_doc->GetNextDoc(curTemplatePos);

//获得视图:
curTemplatePos=m_pdoc->GetFirstViewPosition();
CYourView *m_pview=(CYourView*)m_pdoc->GetNextView(curTemplatePos);

//调用视图函数:
m_pview->Put();

//2)第二种方法:
//获得窗体指针:
CMainFrame *pFrame = (CMainFrame*)AfxGetApp()->m_pMainWnd;

//获得与该窗体符合的视图:
CYourView *m_pView = (CYourView *) pFrame->GetActiveView();

//调用视图函数:
m_pView->Put();

2.如何设置有背景颜色的文本

(1)[解决方法]
用到了CDC::SetBkMode();

[程序实现]
void CMyView::OnDraw(CDC* pDC)
{
CMyDoc* pDoc = GetDocument();
ASSERT_VALID(pDoc);
CRect rcView;//加這兩句
GetClientRect(rcView);
// TODO: add draw code for native data here
CString str (_T("Perfect Text．．．"));
pDC->SetBkMode(TRANSPARENT);
rcView.OffsetRect (1,1);
pDC->SetTextColor(RGB (0,0,0));
pDC->DrawText(str,str.GetLength(),rcView,DT_SINGLELINE | DT_CENTER | DT_VCENTER);
rcView.OffsetRect(-1,-1);
pDC->SetTextColor(RGB (255,0,0));
pDC->DrawText(str,str.GetLength(),rcView,DT_SINGLELINE | DT_CENTER | DT_VCENTER);
}

(2) 建立名为My的SDI或MDI,并响应WM_ERASEBKGND.
BOOL CMyView::OnEraseBkgnd(CDC* pDC)
{
// TODO: Add your message handler code here and/or call default
CBrush Brush (RGB(114,147,171));
// Select the brush into the device context .
CBrush* pOldBrush = pDC->SelectObject(&Brush);
// Get the area that needs to be erased .
CRect ViewClip;
pDC->GetClipBox(&ViewClip);
//Paint the area.
pDC->PatBlt(ViewClip.left,ViewClip.top,ViewClip.Width(),ViewClip.Height(),PATCOPY);
//Unselect brush out of device context .
pDC->SelectObject (pOldBrush );
// Return nonzero to half fruther processing .

return TRUE;
return CView::OnEraseBkgnd(pDC);
}
此方法也适合基类是EditView的SDI或MDI的情况,但是字体的颜色和底色不行.建议用WM_CTLCOLOR.

3.CDC中的竖排文本

在OnDraw成员函数中我想让文本竖直对齐,但CDC类似乎不支持该处理

方法一:如果你的竖直对齐是指旋转文本的话,下面的代码会对你有帮助:该代码检查一个Check box控制,查看文本是否需要旋转.

// m_pcfYTitle is a CFont* to the selected font.
// m_bTotateYTitle is a bool (==TRUE if rotated)

void CPage1::OnRotateytitle()
{
LOGFONT lgf;
m_pcfYTitle->GetLogFont(&lgf);
m_bRotateYTitle=
((CButton*)GetDlgItem(IDC_ROTATEYTITLE))->GetCheck()>0;

// escapement is reckoned clockwise in 1/10ths of a degree:
lgf.lfEscapement=-(m_bRotateYTitle*900);
m_pcfYTitle->DeleteObject();

m_pcfYTitle->CreateFontIndirect(&lgf);
DrawSampleChart();
}
注意如果你从CFontDialog中选择了不同的字体,你应该自己设定LOGFONT的lfEscapement成员.将初始化后的lfEscapement值传到CFontDialog中.

方法二:还有一段代码可参考:

LOGFONT LocalLogFont;

strcpy(LocalLogFont.lfFaceName, TypeFace);

LocalLogFont.lfWeight = fWeight;
LocalLogFont.lfEscapement = Orient;
LocalLogFont.lfOrientation = Orient;

if (MyFont.CreateFontIndirect(&LocalLogFont))

{
cMyOldFont = cdc->SelectObject(&MyFont);
}

4.串太长时往让其末尾显示一个省略号(在SDI或MDI的View中)

[问题提出]
如何在串太长时往让其末尾显示一个省略号(在SDI或MDI的View中)?
[程序实现]
建立名为My的SDI或MDI工程.
void CMyView::OnDraw(CDC* pDC)
{
CMyDoc* pDoc = GetDocument();
ASSERT_VALID(pDoc);
// TODO: add draw code for native data here
pDC->DrawText(CString("It's a long string,so we will add a '...' at the end."),CRect (110, 110, 180, 130),DT_LEFT | DT_END_ELLIPSIS);
//Add ellpsis to middle of string if it does not fit
pDC->DrawText(CString("It's a long string,so we will add a '...' at the end."),CRect (110, 140, 300, 160),DT_LEFT | DT_PATH_ELLIPSIS);
}

5.修改视图背景

How do I change the background color of a view?

To change the background color for a CView, CFrameWnd, or CWnd object, process the WM_ERASEBKGND message. The following code shows how:

BOOL CSampleView::OnEraseBkgnd(CDC* pDC)
{
// Set brush to desired background color.
CBrush backBrush(RGB(255, 128, 128));
// Save old brush.
CBrush* pOldBrush = pDC->SelectObject(&backBrush);
CRect rect;
pDC->GetClipBox(&rect); // Erase the area needed.
pDC->PatBlt(rect.left, rect.top, rect.Width(),
rect.Height(), PATCOPY);
pDC->SelectObject(pOldBrush);
return TRUE;
}

I solved the problem like this:

HBRUSH dlgtest::OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor)
{
switch (nCtlColor)
{
case CTLCOLOR_BTN:
case CTLCOLOR_STATIC:
{
pDC->SetBkMode(TRANSPARENT);
}
case CTLCOLOR_DLG:
{
CBrush* back_brush;
COLORREF color;
color = (COLORREF) GetSysColor(COLOR_BTNFACE);
back_brush = new CBrush(color);
return (HBRUSH) (back_brush->m_hObject);
}
}
return(CFormView::OnCtlColor(pDC, pWnd, nCtlColor));
}