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.}