如何在服务（Service）程序中显示对话框

原文：http://www.vckbase.com/index.php/wv/94

服务程序（Service）一般是不能和用户进行交互的，所以他一般是不能显示窗口的。要和用户进行交互（如显示窗口），我们必须打开用户WinSta0和desktop,下面的这段代码就是打开上述两个，并显示一个dialog：

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01.BOOL CServiceModule::ShowMsgDlg(void)

02.{

03.HDESK   hdeskCurrent;

04.HDESK   hdesk;

05.HWINSTA hwinstaCurrent;

06.HWINSTA hwinsta;

07. 

08.hwinstaCurrent = GetProcessWindowStation();

09.if (hwinstaCurrent == NULL){

10.LogEvent(_T("get window station err"));

11.return FALSE;

12.}

13. 

14.hdeskCurrent = GetThreadDesktop(GetCurrentThreadId());

15.if (hdeskCurrent == NULL){

16.LogEvent(_T("get window desktop err"));

17.return FALSE;

18.}

19. 

20.//打开winsta0

21.hwinsta = OpenWindowStation("winsta0", FALSE,                         

22.WINSTA_ACCESSCLIPBOARD   |

23.WINSTA_ACCESSGLOBALATOMS |

24.WINSTA_CREATEDESKTOP     |

25.WINSTA_ENUMDESKTOPS      |

26.WINSTA_ENUMERATE         |

27.WINSTA_EXITWINDOWS       |

28.WINSTA_READATTRIBUTES    |

29.WINSTA_READSCREEN        |

30.WINSTA_WRITEATTRIBUTES);

31.if (hwinsta == NULL){

32.LogEvent(_T("open window station err"));

33. 

34.return FALSE;

35.}

36. 

37.if (!SetProcessWindowStation(hwinsta)){

38.LogEvent(_T("Set window station err"));

39. 

40.return FALSE;

41.}

42. 

43.//打开desktop

44.hdesk = OpenDesktop("default", 0, FALSE,               

45.DESKTOP_CREATEMENU |

46.DESKTOP_CREATEWINDOW |

47.DESKTOP_ENUMERATE    |

48.DESKTOP_HOOKCONTROL  |

49.DESKTOP_JOURNALPLAYBACK |

50.DESKTOP_JOURNALRECORD |

51.DESKTOP_READOBJECTS |

52.DESKTOP_SWITCHDESKTOP |

53.DESKTOP_WRITEOBJECTS);

54.if (hdesk == NULL){

55.LogEvent(_T("Open desktop err"));

56. 

57.return FALSE;

58.}

59. 

60.SetThreadDesktop(hdesk);

61. 

62.//到这一步，我们获取了和用户交互（如显示窗口）的权利

63.CMsgDlg dlgMsg;

64.//显示一个dialog

65.dlgMsg.DoModal();             

66. 

67.if (!SetProcessWindowStation(hwinstaCurrent))

68.return FALSE;

69. 

70.if (!SetThreadDesktop(hdeskCurrent))

71.return FALSE;

72. 

73.if (!CloseWindowStation(hwinsta))

74.return FALSE;

75. 

76.if (!CloseDesktop(hdesk))

77.return FALSE;

78. 

79.return TRUE;

80.}