1. GDI程式設計基本步驟

MFC OnPaint()函式中程式碼實現步驟

	//獲取DC
		CPaintDC dc(this);
	//建立GDI物件
		//建立畫刷
		CBrush newBrush;
		CBrush *pOldBrush;
		newBrush.CreateSolidBrush(RGB(0,255,0));		
		//建立畫筆
		CPen newPen;
		CPen *pOldPen;
		newPen.CreatePen(PS_SOLID,1,RGB(0,0,255));
		//建立字型
		CFont newFont;
		CFont *pOldFont;
		newFont.CreatePointFont(200,"宋體");
	//把GDI物件寫入DC
		//將畫刷寫入DC
		pOldBrush=dc.SelectObject(&newBrush);
		//將畫筆寫入DC
		pOldPen=dc.SelectObject(&newPen);
		//將字型寫入DC
		pOldFont=dc.SelectObject(&newFont);
	//繪圖和字型輸出
		CRect rc;
		GetClientRect(&rc);
		dc.Rectangle(rc);
		dc.TextOut(150,150,"畫刷綠色，畫筆藍色");
	//恢復畫刷，畫筆和字型
		dc.SelectObject(pOldBrush);
		dc.SelectObject(pOldPen);
		dc.SelectObject(pOldFont);
	//刪除新建畫刷,畫筆和字型
		newBrush.DeleteObject();
		pOldBrush->DeleteObject();
		newPen.DeleteObject();
		pOldPen->DeleteObject();
		newFont.DeleteObject();
		pOldFont->DeleteObject();
	//釋放DC，解構函式直接釋放