新手,做了一个ActiveX控件，只画一条线（Aline）

[cc330]

按左键，线变红

void CAlineCtrl::OnLButtonDown(UINT nFlags, CPoint point)
{
// TODO: Add your message handler code here and/or call default

red=true;
InvalidateControl();
COleControl::OnLButtonDown(nFlags, point);
}


按右键，线变黑
void CAlineCtrl::OnRButtonDown(UINT nFlags, CPoint point)
{
// TODO: Add your message handler code here and/or call default

red=false;
InvalidateControl();
COleControl::OnRButtonDown(nFlags, point);
}


void CAlineCtrl::OnDraw(
CDC* pdc, const CRect& rcBounds, const CRect& rcInvalid)
{
CBrush bkBrush(TranslateColor(GetBackColor()));
pdc->FillRect(rcBounds, &bkBrush);
//先用当时的背景色，把此ActiveX控件的内部不画线的地方涂一下，但发现涂的颜色与背景色不同，请问是什么原因？这样一块一块不好看，我希望没有线的地方与背景一样。


CRect rc;
long Width = rcBounds.right - rcBounds.left;
long Height = rcBounds.bottom - rcBounds.top;

if(Height>Width){
if(red) {
CPen newPen(PS_SOLID,1,(COLORREF) 255); //红色的笔宽度为1
CPen * pOldPen=pdc->SelectObject (&newPen);
pdc->MoveTo(0,0);
pdc->LineTo(0,800);
}

else {
CPen newPen(PS_SOLID,1,(COLORREF) 0); //黑色的笔宽度为1
CPen * pOldPen=pdc->SelectObject (&newPen);
pdc->MoveTo(0,0);
pdc->LineTo(0,800);
}
}

else{
if(red){
CPen newPen(PS_SOLID,1,(COLORREF) 255); //红色的笔宽度为1
CPen * pOldPen=pdc->SelectObject (&newPen);
pdc->MoveTo(0,0);
pdc->LineTo(800,0);
}

else{
CPen newPen(PS_SOLID,1,(COLORREF) 0); //黑色的笔宽度为1
CPen * pOldPen=pdc->SelectObject (&newPen);
pdc->MoveTo(0,0);
pdc->LineTo(800,0);
}
}

}




说明：
我另做了一个Dialog based的project来做背景，在InitInstance里把背景改为白色，插入此ActiveX控件，运行，没有线的地方与背景色不一样，为什么？

BOOL CMy60703tstApp::InitInstance()
{SetDialogBkColor(RGB(225,225,225));//把背景改为白色
AfxEnableControlContainer();

// Standard initialization
// If you are not using these features and wish to reduce the size
// of your final executable, you should remove from the following
// the specific initialization routines you do not need.
#ifdef _AFXDLL
Enable3dControls(); // Call this when using MFC in a shared DLL
#else
Enable3dControlsStatic(); // Call this when linking to MFC statically
#endif

CMy60703tstDlg dlg;
m_pMainWnd = &dlg;
int nResponse = dlg.DoModal();
if (nResponse == IDOK)
{
// TODO: Place code here to handle when the dialog is
// dismissed with OK
}
else if (nResponse == IDCANCEL)
{
// TODO: Place code here to handle when the dialog is
// dismissed with Cancel
}

// Since the dialog has been closed, return FALSE so that we exit the
// application, rather than start the application's message pump.
return FALSE;
}

[大选]

支持啊

[cc330]

真的那么难吗？