让应用程序标题栏的图标按照时间轮换
思路:
1) SetClassLong函数在窗口建成后调用图标文件(事先准备好3个图标文件),在OnCreate中处理
2) 在OnCreate中放置一个SetTimer
3)处理WM_TIIMER消息即OnTime函数
知识点:
用三种方法获取应用程序实例hInstance句柄
1) AfxGetInstanceHandle()
2)theApp.m_hInstance
3)AfxGetApp()->m_hInstance
资源ID转化为资源标识字符串 MAKEINTRESOURCE,这是个宏,WIN32编程中常用.
注意:theApp是在类CStyleApp文件中定义的全局变量CStyleApp theApp,在CMainFrame中要用它,必须先申明
theApp来自外部,即: extern CStyleApp theApp
int CMainFrame::OnCreate(LPCREATESTRUCT lpCreateStruct)
{if (CFrameWnd::OnCreate(lpCreateStruct) == -1)return -1;if (!m_wndToolBar.CreateEx(this, TBSTYLE_FLAT, WS_CHILD | WS_VISIBLE | CBRS_TOP| CBRS_GRIPPER | CBRS_TOOLTIPS | CBRS_FLYBY | CBRS_SIZE_DYNAMIC) ||!m_wndToolBar.LoadToolBar(IDR_MAINFRAME)){TRACE0("Failed to create toolbar\n");return -1; // fail to create}if (!m_wndStatusBar.Create(this) ||!m_wndStatusBar.SetIndicators(indicators,sizeof(indicators)/sizeof(UINT))){TRACE0("Failed to create status bar\n");return -1; // fail to create}// TODO: Delete these three lines if you don't want the toolbar to// be dockablem_wndToolBar.EnableDocking(CBRS_ALIGN_ANY);EnableDocking(CBRS_ALIGN_ANY);DockControlBar(&m_wndToolBar);//------先加载图标到数字m_hIcon[], 用SetClassLong()调用,修改标题图标,放置一个定时器m_hIcon[0] =LoadIcon(AfxGetInstanceHandle(),MAKEINTRESOURCE(IDI_ICON1));extern CStyleApp theApp; // 要用theApp这个全局的应用程序对象,需要申明下它是CStyleApp中定义过的.m_hIcon[1] =LoadIcon(theApp.m_hInstance,MAKEINTRESOURCE(IDI_ICON2));m_hIcon[2] =LoadIcon(AfxGetApp()->m_hInstance,MAKEINTRESOURCE(IDI_ICON3));SetClassLong(this->m_hWnd,GCL_HICON,(LONG)m_hIcon[0]);//把m_hIcon[0]设置为窗口创建后的默认图标SetTimer(1,1000,NULL); //设置一个定时器,定时产生WM_TIMER消息return 0;
}
// 响应定时器SetTimer(1,1000,NULL)的WM_TIMER消息函数
void CMainFrame::OnTimer(UINT nIDEvent)
{// TODO: Add your message handler code here and/or call defaultstatic int index =1;SetClassLong(this->m_hWnd,GCL_HICON,(LONG)m_hIcon[index]); index++;if(index==3)index=0; // 或者取3的取模运算:index=++index%3;CFrameWnd::OnTimer(nIDEvent);
}