实现对话框最大化时控件也随比例最大化或者还原

方法一：单个控件ID操作

第一步、在对话框类中（.h文件）定义如下变量和函数

定义如下几个变量：

BOOL bChangeFlag;
float m_Multiple_height;
float m_Multiple_width;

void ReSize(int nID);

重载消息 WM_SIZE

afx_msg void OnSize(UINT nType, int cx, int cy);  

第二步、在OnInitDialog()中 计算出当前对话框的大小与最大化后大小

//对话框初始大小
CRect rect;
GetClientRect(rect);
LONG m_nDlgWidth = rect.Width();
LONG m_nDlgHeight = rect.Height();

//计算最大化后的大小(即全屏大小)
CRect rectWorkArea;  
SystemParametersInfo(SPI_GETWORKAREA, 0, &rectWorkArea, SPIF_SENDCHANGE);  
LONG m_nWidth = rectWorkArea.Width();
LONG m_nHeight = rectWorkArea.Height();

//计算放大倍数(要用float值，否则误差很大)
m_Multiple_width = float(m_nWidth)/float(m_nDlgWidth);
m_Multiple_height = float(m_nHeight)/float(m_nDlgHeight);
change_flag = TRUE;//用来判断OnSize执行时，OninitDialg是否已经执行了

第三步、给对话框添加 WM_SIZE消息

//给对话框添加 WM_SIZE消息  
void CStuDemoDlg::OnSize(UINT nType, int cx, int cy)   
{  
	CDialog::OnSize(nType, cx, cy);  
  
	// TODO: Add your message handler code here  
	
	if (bChangeFlag)//如果OninitDlg已经调用完毕  
	{  
	    ReSize(IDC_STATIC_1);  
	    ReSize(IDC_STATIC_2);         
	    ReSize(IDC_EDIT11);//  
	    ReSize(IDC_EDIT12);//  
	    ReSize(IDC_LIST_SHOW);  
	    ReSize(IDC_BUTTON_ADD);  
	    ReSize(IDC_BUTTON_DEL);  
	    ReSize(IDOK);  
	    ReSize(IDCANCEL);  
	    
	    //恢复放大倍数，并保存 (确保还原时候能够还原到原来的大小)  
	    m_Multiple_width = float(1)/m_Multiple_width;  
	    m_Multiple_height = float(1)/m_Multiple_height;  
	}  
}  

第四步、刷新控件：根据比例计算控件缩放的大小，然后movewindow 到新矩形上

void CStuDemoDlg::ReSize(int nID)
{
    CRect Rect;
    GetDlgItem(nID)->GetClientRect(Rect);
    
    //计算控件左上角点
    CPoint OldTLPoint,NewTLPoint;
    OldTLPoint = Rect.TopLeft();
    NewTLPoint.x = long(OldTLPoint.x * m_Multiple_width);
    NewTLPoint.y = long(OldTLPoint.y * m_Multiple_height);
    
    //计算控件右下角点
    CPoint OldBRPoint,NewBRPoint; 
    OldBRPoint = Rect.BottomRight();
    NewBRPoint.x = long(OldBRPoint.x * m_Multiple_width);
    NewBRPoint.y = long(OldBRPoint.y * m_Multiple_height);
    
    //移动控件到新矩形
    Rect.SetRect(NewTLPoint, NewBRPoint);
    GetDlgItem(nID)->MoveWindow(Rect, TRUE);
}

方法二：集体控件操作

第一步、在对话框类中（.h文件）定义如下变量和函数

void ReSize();

LONG m_nOldWidth;
LONG m_nOldHeight;

重载消息 WM_SIZE

afx_msg void OnSize(UINT nType, int cx, int cy); 

第二步、在OnInitDialog()中计算出原始对话框的大小

//获取客户区大小
CRect rect;
GetClientRect(&rect);
m_nOldWidth = rect.Width();
m_nOldHeight = rect.Height()

第三步、添加 WM_SIZE消息

void CStuDemoDlg::OnSize(UINT nType, int cx, int cy)
{
    CDialog::OnSize(nType, cx, cy);
    // TODO: Add your message handler code here
    
    if (nType == SIZE_RESTORED || nType == SIZE_MAXIMIZED)
    {
        ReSize();
    }
}

第四步、刷新控件函数

void CStuDemoDlg::ReSize()
{
    //保存长宽缩放比例
    float fsp[2];

    //计算当前窗口大小
    CRect rect;
    GetClientRect(&rect);
    
    //计算当前缩放比例
    fsp[0] = (float)rect.Width() / m_nOldWidth;
    fsp[1] = (float)rect.Height() / m_nOldHeight;

    int nId = 0; //控件ID
    CPoint OldTLPoint, NewTLPoint; //左上角  
    CPoint OldBRPoint, NewBRPoint; //右下角  

    //列出所有控件
    HWND hwndChild = ::GetWindow(m_hWnd, GW_CHILD);

    while(hwndChild)
    {
        //取得控件ID
        nId = ::GetDlgCtrlID(hwndChild);

        //取得控件原来位置
        GetDlgItem(nId)->GetClientRect(rect);

        //计算缩放后的位置
        OldTLPoint = rect.TopLeft(); 
        NewTLPoint.x = long(OldTLPoint.x * fsp[0]);
        NewTLPoint.y = long(OldTLPoint.y * fsp[1]);

        OldBRPoint = rect.BottomRight();
        NewBRPoint.x = long(OldBRPoint.x * fsp[0]);
        NewBRPoint.y = long(OldBRPoint.y * fsp[1]);

        //重新设置控件
        rect.SetRect(NewTLPoint, NewBRPoint);
        GetDlgItem(nId)->MoveWindow(rect,TRUE);

        //继续下一个控件
        hwndChild = ::GetWindow(hwndChild, GW_HWNDNEXT);
    }
    
    //保存新的窗口大小
    m_nOldWidth = rect.Width();
    m_nOldHeight = rect.Height();
}