#pragma once
#include "stdafx.h"

#ifndef BACK_COLOR
//COLORREF DrawerBackColor = RGB(192, 192, 192);

#define BACK_COLOR
#endif // !BACK_COLOR
class DCHelp
{
public:
	//static COLORREF DrawerBackColor;// = RGB(192, 192, 192);
	// 清空画布
	static bool ClearDC(CDC* pCdc, COLORREF clrBack)
	{
		//if (symbolFlag)
		//{
		//	clrBack = RGB(192, 192, 192);
		//}
		//else
		//{
		//	clrBack = RGB(255, 255, 255);
		//}
		//
		CRect clip;
		pCdc->GetClipBox(clip);

		//if (pCdc->GetDeviceCaps(RASTERCAPS)&RC_BITBLT)
		//{
		//	CBrush br(clrBack);
		//	CBrush* pOldBrush = pCdc->SelectObject(&br);
		//	pCdc->PatBlt(clip.left, clip.top, clip.Width(), clip.Height(), PATCOPY);//并不是所有设备支持此函数
		//	pCdc->SelectObject(pOldBrush);
		//}
		//else
			pCdc->FillSolidRect(clip, clrBack);

		return true;
	}
	// 清空画布
	static bool ClearDCNull(CDC* pCdc, COLORREF clrBack)
	{
		CRect clip;
		pCdc->GetClipBox(clip);

		if (pCdc->GetDeviceCaps(RASTERCAPS)&RC_BITBLT)
		{
			CBrush* pBrush= CBrush::FromHandle((HBRUSH)GetStockObject(NULL_BRUSH));
			CBrush* pOldBrush = pCdc->SelectObject(pBrush);
			pCdc->PatBlt(clip.left, clip.top, clip.Width(), clip.Height(), PATCOPY);//并不是所有设备支持此函数
			pCdc->SelectObject(pOldBrush);
		}
		else {

			CBrush *pBrush = CBrush::FromHandle((HBRUSH)GetStockObject(NULL_BRUSH));
			//FromHandle一个画刷句柄转化为一个画刷对象
			//GetStockObject(NULL) 获取一个透明画刷句柄
			CBrush *pOldBrush = pCdc->SelectObject(pBrush);// 把画刷加载到设备表述表
			pCdc->Rectangle(clip);
			pCdc->SelectObject(pOldBrush);

			//pCdc->FillSolidRect(clip, clrBack);
		}
		return true;
	}
};