如何在控件上设置图像，点击时更改

如何在控件上设置图像，点击时更改

介绍函数：
void AFXAPI DDX_Control( CDataExchange* pDX , int nIDC , CWnd& rControl );
参数一：指向CDataExchange的指针，用于建立资料交换设备上下文；
参数二：控件IDC;
参数三：控件变量。
重写SetIcon（）函数：
 头文件：
  void SetIcon(int nIconInId, int nIconOutId = NULL);  //带参数的成员函数
 源文件：

void CButtonST::SetIcon(int nIconInId, int nIconOutId)

{

       HICON hIconIn;         //定义HICON 变量，用于保存图片

       HICON hIconOut;

       HINSTANCE hInstResource = AfxFindResourceHandle(MAKEINTRESOURCE(nIconInId), RT_GROUP_ICON);
       //鼠标点击时获得应用资源句柄
       hIconIn = (HICON)::LoadImage(hInstResource/*AfxGetApp()->m_hInstance*/, MAKEINTRESOURCE(nIconInId), IMAGE_ICON, 0, 0, 0);
       // 鼠标移开时加载图片
       hIconOut = (nIconOutId == NULL) ? NULL : (HICON)::LoadImage(hInstResource/*AfxGetApp()->m_hInstance*/,    MAKEINTRESOURCE(nIconOutId), IMAGE_ICON, 0, 0, 0);
       SetIcon(hIconIn, hIconOut);   //调用
}

void CButtonST::SetIcon(HICON hIconIn, HICON hIconOut)
{
       // Note: the following two lines MUST be here! even if
       // BoundChecker says they are unnecessary!
       if (m_hIconIn != NULL) ::DestroyIcon(m_hIconIn);        //判定是否与图片相关联
       if (m_hIconOut != NULL) ::DestroyIcon(m_hIconOut);

       // Set icon when the mouse is IN the button
       m_hIconIn = hIconIn;

       // Set icon when the mouse is OUT the button
       m_hIconOut = (hIconOut == NULL) ? m_hIconIn : hIconOut;

       ICONINFO ii;             //ICONINFO 结构体
      // Get icon dimension
       ZeroMemory(&ii, sizeof(ICONINFO));        //ii内存设0
       ::GetIconInfo(m_hIconIn, &ii);                       //设置自定义图标
       m_cxIcon = (BYTE)(ii.xHotspot * 2);
       m_cyIcon = (BYTE)(ii.yHotspot * 2);
       ::DeleteObject(ii.hbmMask);
       ::DeleteObject(ii.hbmColor);

       RedrawWindow();

} // End of SetIcon

程序流程：
a）添加头文件
     CButton m_btn；定义一对象
b）在新建框架类中初始化
 BOOL CMy5Dlg::OnInitDialog()
{
      m_btn.SetIcon(IDI_ICON1,IDI_ICON2); //设置两幅图标
}
c）鼠标点击交换图片
 void CMy5Dlg::DoDataExchange(CDataExchange* pDX)
{
           DDX_Control(pDX,IDC_BUTTON1,m_btn);
}