MFC中触发OnSize讯息后Picture Control上画的图不见了。不知道覆盖了还是压根就整个控件丢失了

MFC中触发OnSize消息后Picture Control上画的图不见了。不知道覆盖了还是压根就整个控件丢失了。
初始状态

调用OnSize后调试明明还调用了OnPaint重绘Picture Control（关联的控件变量m_Chart）

求大神帮忙看看哪里出了问题感激不尽
贴上OnSize和OnPaint的代码
OnSize()

void CChartForm::OnSize(UINT nType, int cx, int cy)

{

	CDialog::OnSize(nType, cx, cy);


	// When creating dialog box, the control has not been created, so you can't change the size(must add these two lines of code)

	if(!IsWindowVisible())

		return;


	// Resizing the form


	// Hide buttons while we reposition them

	m_OK.ShowWindow(SW_HIDE);

	m_CancelButton.ShowWindow(SW_HIDE);

	m_Options.ShowWindow(SW_HIDE);

	m_ClearButton.ShowWindow(SW_HIDE);

	m_HelpButton.ShowWindow(SW_HIDE);


	int iWinWidth = GetWidth(this);

	int iWinHeight = GetHeight(this);

	// Check that the form's new height and width meet minimum requirements

	if (iWinHeight<OrigHeight) {

		SetHeight(this, OrigHeight);

	}

	if (iWinWidth<OrigWidth) {

		SetWidth(this, OrigWidth);

	}

	iWinWidth = GetWidth(this);

	iWinHeight = GetHeight(this);


	// Re-dimension chart picture box accordingly

	SetWidth(m_Chart, iWinWidth-120/kTP);

	SetHeight(m_Chart, iWinHeight-1770/kTP);

	// Re-Position OK and CANCEL buttons on toolbar

	SetLeft(m_OK, iWinWidth-4230/kTP);

	SetLeft(m_CancelButton, iWinWidth-2910/kTP);

	SetLeft(m_HelpButton, iWinWidth-1590/kTP);

	SetLeft(m_Options, 120/kTP);

	SetLeft(m_ClearButton, 1440/kTP);

	SetTop(m_OK, iWinHeight-1305/kTP);

	SetTop(m_CancelButton, iWinHeight-1305/kTP);

	SetTop(m_Options, iWinHeight-1305/kTP);

	SetTop(m_ClearButton, iWinHeight-1305/kTP);

	SetTop(m_HelpButton, iWinHeight-1305/kTP);


	// Redisplay buttons

	m_OK.ShowWindow(SW_SHOW);

	m_CancelButton.ShowWindow(SW_SHOW);

	m_Options.ShowWindow(SW_SHOW);

	m_ClearButton.ShowWindow(SW_SHOW);

	m_HelpButton.ShowWindow(SW_SHOW);


	// Re-dimension toolbar and statusbar accordingly

	m_Toolbar1.SetWindowPos( NULL,0,0,iWinWidth,28,SWP_NOZORDER | SWP_NOMOVE );

	m_TimeStatusBar.SetWindowPos( NULL,0,iWinHeight-25,iWinWidth,25,SWP_NOZORDER );

}

OnPaint()

void CChartForm::OnPaint() 

{

	if (IsIconic())

	{

		CPaintDC dc(this); // device context for painting


		SendMessage(WM_ICONERASEBKGND, reinterpret_cast<WPARAM>(dc.GetSafeHdc()), 0);


		// Center icon in client rectangle

		int cxIcon = GetSystemMetrics(SM_CXICON);

		int cyIcon = GetSystemMetrics(SM_CYICON);

		CRect rect;

		GetClientRect(&rect);

		int x = (rect.Width() - cxIcon + 1) / 2;

		int y = (rect.Height() - cyIcon + 1) / 2;


		// Draw the icon

		dc.DrawIcon(x, y, m_hIcon);

	}

	else

	{

		CPaintDC dc(this); // device context for painting


		// Set back color for Chart control

		CRect rect;

		CDC * pDC = m_Chart.GetDC();

		m_Chart.GetClientRect(&rect);

		pDC->FillRect(rect,&CBrush(RGB(255,255,255)));

		m_Chart.ReleaseDC(pDC);


		DrawChart(this->m_Chart, TheChartData, Maximum, Minimum, fSnapSpacing, SnapSpacingFormat, FirstSlot, LastSlot, HoursPerDay, SlotsPerHour, ScheduleType, VerticalLines, bClearWindow, Major, Minor);

		bClearWindow = false;


		CDialog::OnPaint();

	}

}

------解决思路----------------------
把 CDialog::OnPaint()放在前面试试
------解决思路----------------------
没发现你的OnSize里面调用了OnPaint。
------解决思路----------------------
    SetWidth(m_Chart, iWinWidth-120/kTP);
    SetHeight(m_Chart, iWinHeight-1770/kTP);
后加
       CRect rect;
        m_Chart.GetWindowRect(&rect);

看 对不对