.NET Main函数参数解释过程和特殊规则

在开发软件里，有时候需要改变窗口上标题的文字。比如按钮上的文字，为了适应多国语言的显示，就需要改变它显示的内容。这时就需要使用SetWindowText函数来改它的内容。下面的例子就实现改变按钮的标题。 函数SetWindowText声明如下：WINUSERAPIBOOLWINAPISetWindowTextA(    __in HWND hWnd,    __in_opt LPCSTR lpString);WINUSERAPIBOOLWINAPISetWindowTextW(    __in HWND hWnd,    __in_opt LPCWSTR lpString);#ifdef UNICODE#define SetWindowText SetWindowTextW#else#define SetWindowText SetWindowTextA#endif // !UNICODEhWnd是窗口的句柄。lpString是要需要显示的文字。 调用这个函数的例子如下：#001 //#002 // 响应命令.#003 // 蔡军生 2007/09/14 QQ:9073204#004 //#005 LRESULT CCaiWinMsg::OnCommand(int nID,int nEvent)#006 { #007  // 菜单选项命令响应:#008  switch (nID)#009  {#010  case IDC_CREATEBTN:#011         //显示一个按钮。#012         if (!m_hBtn)#013         {#014                m_hBtn = CreateWindow(_T("BUTTON"),_T("按钮"),#015                    WS_VISIBLE|WS_CHILD|BS_PUSHBUTTON,#016                    50,50,100,32,#017                     m_hWnd,(HMENU)IDC_BTN,m_hInstance,NULL);#018         }                                           #019         break;#020  case IDC_BTN: #021         OutputDebugString(_T("按钮按下/r/n"));#022         {#023               static bool bChangeText = true;#024               if (bChangeText)#025               {#026                    //设置按钮的文字。#027                   SetWindowText(m_hBtn,_T("改变它"));#028               }#029               else#030               {#031                    //设置按钮的文字。#032                   SetWindowText(m_hBtn,_T("按钮"));#033               }#034 #035               //每一次都改变。#036               bChangeText = !bChangeText; #037         }#038         break;#039  default:#040         return CCaiWin::OnCommand(nID,nEvent);#041  }#042 #043  return 1;#044 }