MFC CStatic 透明重绘 使用双缓冲

在工作中经常需要使用CStatic  在该控件属性中设置透明 是无效的 需通过代码实现其透明

方法1 

直接在父窗体的OnCtlColor中更改

HBRUSH CDlgStockPrice::OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor)
{
	HBRUSH hbr = CDialogEx::OnCtlColor(pDC, pWnd, nCtlColor);
   // TODO:  在此更改 DC 的任何特性
    // TODO:  如果默认的不是所需画笔，则返回另一个画笔 
	if (nCtlColor = CTLCOLOR_STATIC)
	{
		pDC->SetBkMode(TRANSPARENT);
		return   (HBRUSH)::GetStockObject(NULL_BRUSH);
	}
	return hbr;
}

方法二 定义一个类 继承自CStatic 重写OnPaint 方法

#pragma once


// CColorStaticEx

class CColorStaticEx : public CStatic
{
	DECLARE_DYNAMIC(CColorStaticEx)

public:
	CColorStaticEx();
	virtual ~CColorStaticEx();

protected:
	DECLARE_MESSAGE_MAP()
public:
	void SetFont(CFont font);   //设置字体
	void SetFontSize(int size);  //设置字体大小
	void SetTextColor(COLORREF color);  //设置字体颜色
	void SetHightFontColor(COLORREF color);
	void SetHightTextSize(int size);
	void IsDrawBorad(bool draw);
private:
	void DrawBoard(CDC* dc,CRect rct);
private:
	int    m_size;
	CString   m_str;
	CString   m_curstr;
	CFont  m_font;
	COLORREF  m_text_color;
	COLORREF  m_text_high_color;
	int    m_text_high_size;
	int    m_text_size;
	bool   m_bDrawBoard;
public:
	afx_msg void OnPaint();
	void SetWindowText(LPCTSTR lpszString);
};

源文件

// ColorStaticEx.cpp : 实现文件
//

#include "stdafx.h"
#include "StockTradeClient.h"
#include "ColorStaticEx.h"


// CColorStaticEx

IMPLEMENT_DYNAMIC(CColorStaticEx, CStatic)

CColorStaticEx::CColorStaticEx()
{
	m_text_size = 100;
	m_text_high_size = 200;
	
	m_text_color = RGB(0,0,0);
	m_text_high_color = RGB(255,0,0);
	m_curstr = "";
	m_bDrawBoard = true;
//	m_high_font.CreateFont(-24,0,0,0,FW_BOLD,FALSE,FALSE,0,DEFAULT_CHARSET,OUT_DEFAULT_PRECIS,CLIP_DEFAULT_PRECIS,DEFAULT_QUALITY,DEFAULT_PITCH|FF_SWISS,_T("微软雅黑"));

}

CColorStaticEx::~CColorStaticEx()
{
}

BEGIN_MESSAGE_MAP(CColorStaticEx, CStatic)
	ON_WM_PAINT()
END_MESSAGE_MAP()



void CColorStaticEx::SetFont(CFont font)
{
	//m_font = font;
}


void CColorStaticEx::SetFontSize(int size)
{
	m_font.CreatePointFont(size, _T("微软雅黑"));
}

void CColorStaticEx::SetTextColor(COLORREF color)
{
	m_text_color = color;
}

void CColorStaticEx::SetHightFontColor(COLORREF color)
{
	m_text_high_color = color;
}

void CColorStaticEx::SetHightTextSize(int size)
{
	m_text_high_size = size;
}




void CColorStaticEx::IsDrawBorad(bool draw) //是否画边界
{
	m_bDrawBoard = draw;
}


void CColorStaticEx::DrawBoard(CDC* dc,CRect rct) //绘制边界
{
	CPen pen;
	pen.CreatePen(PS_SOLID, 2, RGB(255, 0, 0));
	CPen  *oldPen;
	oldPen = dc->SelectObject(&pen);
	dc->MoveTo(rct.left, rct.top);
	dc->LineTo(rct.right, rct.top);
	dc->LineTo(rct.right, rct.bottom);
	dc->LineTo(rct.left, rct.bottom);
	dc->LineTo(rct.left, rct.top);
	dc->SelectObject(oldPen);

}

void CColorStaticEx::SetWindowText(LPCTSTR lpszString)
{
	m_str = (CString)lpszString;
	CRect rct;
	GetWindowRect(&rct);
	GetParent()->ScreenToClient(&rct);
	GetParent()->InvalidateRect(&rct); //使区域无效 重绘防止出现文本重叠
}



void CColorStaticEx::OnPaint()
{
	CPaintDC dc(this); // device context for painting
	CRect rct;
	GetWindowRect(&rct);
	ScreenToClient(&rct);

	CPaintDC *pDC = &dc;
	pDC->SetBkMode(TRANSPARENT);
	
	/*内存绘图*/
	CDC memDC;
	memDC.CreateCompatibleDC(&dc);
    CBitmap m_MemMap;
    m_MemMap.CreateCompatibleBitmap(pDC, rct.Width(), rct.Height());
    memDC.SelectObject(&m_MemMap);
	memDC.FillSolidRect(rct, RGB(236, 243, 246));
    memDC.SetBkMode(TRANSPARENT);

	if (m_curstr != m_str)
	{
		m_font.CreatePointFont(200, L"微软雅黑");
		memDC.SetTextColor(m_text_high_color);
		memDC.DrawText(m_str, rct, DT_VCENTER | DT_VCENTER | DT_SINGLELINE);
		if (m_bDrawBoard)  DrawBoard(&memDC,rct);
		m_curstr = m_str;
	}

	else
	{
        memDC.SetTextColor(m_text_color);
		memDC.DrawText(m_str, rct, DT_VCENTER | DT_VCENTER | DT_SINGLELINE);
		if (m_bDrawBoard)  DrawBoard(&memDC,rct);
	}

    /*复制到界面dc*/
    pDC->BitBlt(rct.left, rct.top, rct.Width(), rct.Height(), &memDC, 0, 0, SRCCOPY);

	/*清理内存*/
	m_MemMap.DeleteObject();
	memDC.DeleteDC();
}