【求助】控件设置透明后，背景变成黑色了。

#include "stdafx.h"

#include "testbg.h"

#include "Test2.h"





// CTest2 对话框



IMPLEMENT_DYNAMIC(CTest2, CDialog)



CTest2::CTest2(CWnd* pParent /*=NULL*/)

	: CDialog(CTest2::IDD, pParent)

{



}



CTest2::~CTest2()

{

}



void CTest2::DoDataExchange(CDataExchange* pDX)

{

	CDialog::DoDataExchange(pDX);

}





BEGIN_MESSAGE_MAP(CTest2, CDialog)

	ON_WM_ERASEBKGND()

	ON_WM_CTLCOLOR()

END_MESSAGE_MAP()





// CTest2 消息处理程序



BOOL CTest2::OnEraseBkgnd(CDC* pDC)

{

	// TODO: 在此添加消息处理程序代码和/或调用默认值



	CBitmap m_BkGndBmp;

	m_BkGndBmp.LoadBitmap(IDB_BITMAP1);

	CRect rcClient;

	GetClientRect(&rcClient);

	BITMAP bm;

	m_BkGndBmp.GetBitmap(&bm);

	CDC memDC;

	memDC.CreateCompatibleDC(pDC);

	CBitmap *pOldBmp = memDC.SelectObject(&m_BkGndBmp);

	pDC->StretchBlt(0,0,rcClient.Width(),rcClient.Height(),&memDC,0,0,bm.bmWidth,bm.bmHeight,SRCCOPY);

	memDC.SelectObject(pOldBmp);

	memDC.DeleteDC();

	return TRUE;

}



HBRUSH CTest2::OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor)

{

	HBRUSH hbr = CDialog::OnCtlColor(pDC, pWnd, nCtlColor);



	// TODO:  在此更改 DC 的任何属性



	// TODO:  如果默认的不是所需画笔，则返回另一个画笔

	if(nCtlColor == CTLCOLOR_BTN 

		|| nCtlColor == CTLCOLOR_STATIC 

		|| nCtlColor == CTLCOLOR_EDIT)

	{

		pDC->SetTextColor(RGB(0,255,255));

		pDC->SetBkMode(TRANSPARENT);

		return (HBRUSH)GetStockObject(NULL_BRUSH); 

	}

	

	pDC->SetTextColor(RGB(0,0,255));

	pDC->SetBkMode(TRANSPARENT);

	return hbr;

}