MFC更换画笔（画刷）颜色以及画眼睛（GDI画图）

MFC画眼睛###

• 由于画笔一旦创建后就无法修改。所以要修改画笔的颜色要用DeleteObject（）函数将其删除​，之后再创建新的画笔
• 例子：换为白色

    CBrush brush, *oldBrush;//创建画刷

	brush.CreateSolidBrush(RGB(0,0,0));//原来为黑色

	oldBrush=pDC->SelectObject(&brush);

	pDC->Ellipse(0,0,200,100);//画一个椭圆

	brush.DeleteObject();//删掉原来brush

	brush.CreateSolidBrush(RGB(255, 251, 240));//更改颜色

	oldBrush=pDC->SelectObject(&brush);//重新选取

	pDC->Ellipse(50,0,150,100);//再画一个颜色不同的

    pDC->SelectObject(oldBrush);//还回画刷

• 只给出OnDraw(CDC* pDC)函数。

void CJustPaintView::OnDraw(CDC* pDC)//paint an eye

{

	CJustPaintDoc* pDoc = GetDocument();

	ASSERT_VALID(pDoc);

	// TODO: add draw code for native data here

	CRect rect;

	GetClientRect(&rect);

	pDC->SetMapMode(MM_ANISOTROPIC);

	pDC->SetWindowExt(rect.Width(), rect.Height());

	pDC->SetViewportExt(rect.Width(), -rect.Height());

	pDC->SetViewportOrg(rect.Width()/2, rect.Height()/2);

	rect.OffsetRect(-rect.Width()/2, -rect.Height()/2);//erweizuobiaoxi

	CBrush brush, *oldBrush;

	brush.CreateSolidBrush(RGB(0,0,0));

	oldBrush=pDC->SelectObject(&brush);

	pDC->Ellipse(0,0,200,100);

	brush.DeleteObject();

	//change color of brush

	brush.CreateSolidBrush(RGB(255, 251, 240));

	oldBrush=pDC->SelectObject(&brush);

	pDC->Ellipse(50,0,150,100);

	brush.DeleteObject();

	//change color of brush

	brush.CreateSolidBrush(RGB(0,0,0));

	oldBrush=pDC->SelectObject(&brush);

	pDC->Ellipse(50,25,150,75);

	brush.DeleteObject();

	//change color of brush

	brush.CreateSolidBrush(RGB(255,0,0));

	oldBrush=pDC->SelectObject(&brush);

	pDC->Ellipse(75,25,125,75);

	pDC->SelectObject(oldBrush);

}

效果