MFC更換畫筆（畫刷）顏色以及畫眼睛（GDI畫圖）

MFC畫眼睛###

換畫筆（畫刷）顏色(參考鏈接：https://blog.csdn.net/sunxiving/article/details/51272001)

• 由於畫筆一旦創建后就無法修改。所以要修改畫筆的顏色要用DeleteObject（）函數將其刪除​，之后再創建新的畫筆
• 例子：換為白色

    CBrush brush, *oldBrush;//創建畫刷
	brush.CreateSolidBrush(RGB(0,0,0));//原來為黑色
	oldBrush=pDC->SelectObject(&brush);
	pDC->Ellipse(0,0,200,100);//畫一個橢圓
	brush.DeleteObject();//刪掉原來brush

	brush.CreateSolidBrush(RGB(255, 251, 240));//更改顏色
	oldBrush=pDC->SelectObject(&brush);//重新選取
	pDC->Ellipse(50,0,150,100);//再畫一個顏色不同的
    pDC->SelectObject(oldBrush);//還回畫刷

沒有參考代碼，嘗試自己畫一波眼睛簡圖。

• 只給出OnDraw(CDC* pDC)函數。

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