MFC更换画笔（画刷）颜色以及画眼睛（GDI画图）

MFC画眼睛###

换画笔（画刷）颜色(参考链接：https://blog.csdn.net/sunxiving/article/details/51272001)

• 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

没有参考代码，尝试自己画一波眼睛简图。

• 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