WaitForMultipleObjects怎么得到具体的事件参数

yakczh_cu

1. 
   
2. #include <windows.h>
   
3. #include <stdlib.h>
   
4. #include <stdio.h>
   
5. #include <tchar.h>
   
6. 
   
7. void RefreshDirectory(LPTSTR);
   
8. void RefreshTree(LPTSTR);
   
9. void WatchDirectory(LPTSTR);
   
10. 
    
11. void _tmain(int argc, TCHAR *argv[])
    
12. {
    
13.     if(argc != 2)
    
14.     {
    
15.         _tprintf(TEXT("Usage: %s <dir>\n"), argv[0]);
    
16.         return;
    
17.     }
    
18. 
    
19.     WatchDirectory(argv[1]);
    
20. }
    
21. 
    
22. void WatchDirectory(LPTSTR lpDir)
    
23. {
    
24.    DWORD dwWaitStatus;
    
25.    HANDLE dwChangeHandles[2];
    
26.    TCHAR lpDrive[4];
    
27.    TCHAR lpFile[_MAX_FNAME];
    
28.    TCHAR lpExt[_MAX_EXT];
    
29. 
    
30.    _tsplitpath_s(lpDir, lpDrive, 4, NULL, 0, lpFile, _MAX_FNAME, lpExt, _MAX_EXT);
    
31. 
    
32.    lpDrive[2] = (TCHAR)'\\';
    
33.    lpDrive[3] = (TCHAR)'\0';
    
34. 
    
35. // Watch the directory for file creation and deletion.
    
36. 
    
37.    dwChangeHandles[0] = FindFirstChangeNotification(
    
38.       lpDir,                         // directory to watch
    
39.       TRUE,                         // do not watch subtree
    
40.       FILE_NOTIFY_CHANGE_FILE_NAME); // watch file name changes
    
41. 
    
42.    if (dwChangeHandles[0] == INVALID_HANDLE_VALUE)
    
43.    {
    
44.      printf("\n ERROR: FindFirstChangeNotification function failed.\n");
    
45.      ExitProcess(GetLastError());
    
46.    }
    
47. 
    
48. // Watch the subtree for directory creation and deletion.
    
49. 
    
50.    dwChangeHandles[1] = FindFirstChangeNotification(
    
51.       lpDrive,                       // directory to watch
    
52.       TRUE,                          // watch the subtree
    
53.       FILE_NOTIFY_CHANGE_DIR_NAME);  // watch dir name changes
    
54. 
    
55.    if (dwChangeHandles[1] == INVALID_HANDLE_VALUE)
    
56.    {
    
57.      printf("\n ERROR: FindFirstChangeNotification function failed.\n");
    
58.      ExitProcess(GetLastError());
    
59.    }
    
60. 
    
61. 
    
62. // Make a final validation check on our handles.
    
63. 
    
64.    if ((dwChangeHandles[0] == NULL) || (dwChangeHandles[1] == NULL))
    
65.    {
    
66.      printf("\n ERROR: Unexpected NULL from FindFirstChangeNotification.\n");
    
67.      ExitProcess(GetLastError());
    
68.    }
    
69. 
    
70. // Change notification is set. Now wait on both notification
    
71. // handles and refresh accordingly.
    
72. 
    
73.    while (TRUE)
    
74.    {
    
75.    // Wait for notification.
    
76. 
    
77.       printf("\nWaiting for notification...\n");
    
78. 
    
79.       dwWaitStatus = WaitForMultipleObjects(2, dwChangeHandles,
    
80.          FALSE, INFINITE);
    
81. 
    
82.       switch (dwWaitStatus)
    
83.       {
    
84.          case WAIT_OBJECT_0:
    
85. 
    
86.          // A file was created, renamed, or deleted in the directory.
    
87.          // Refresh this directory and restart the notification.
    
88. 
    
89.              RefreshDirectory(lpDir);
    
90.              if ( FindNextChangeNotification(dwChangeHandles[0]) == FALSE )
    
91.              {
    
92.                printf("\n ERROR: FindNextChangeNotification function failed.\n");
    
93.                ExitProcess(GetLastError());
    
94.              }
    
95.              break;
    
96. 
    
97.          case WAIT_OBJECT_0 + 1:
    
98. 
    
99.          // A directory was created, renamed, or deleted.
    
100.          // Refresh the tree and restart the notification.
     
101. 
     
102.              RefreshTree(lpDrive);
     
103.              if (FindNextChangeNotification(dwChangeHandles[1]) == FALSE )
     
104.              {
     
105.                printf("\n ERROR: FindNextChangeNotification function failed.\n");
     
106.                ExitProcess(GetLastError());
     
107.              }
     
108.              break;
     
109. 
     
110.          case WAIT_TIMEOUT:
     
111. 
     
112.          // A timeout occurred, this would happen if some value other
     
113.          // than INFINITE is used in the Wait call and no changes occur.
     
114.          // In a single-threaded environment you might not want an
     
115.          // INFINITE wait.
     
116. 
     
117.             printf("\nNo changes in the timeout period.\n");
     
118.             break;
     
119. 
     
120.          default:
     
121.             printf("\n ERROR: Unhandled dwWaitStatus.\n");
     
122.             ExitProcess(GetLastError());
     
123.             break;
     
124.       }
     
125.    }
     
126. }
     
127. 
     
128. void RefreshDirectory(LPTSTR lpDir)
     
129. {
     
130.    // This is where you might place code to refresh your
     
131.    // directory listing, but not the subtree because it
     
132.    // would not be necessary.
     
133. 
     
134.    _tprintf(TEXT("Directory (%s) changed.\n"), lpDir);
     
135. }
     
136. 
     
137. void RefreshTree(LPTSTR lpDrive)
     
138. {
     
139.    // This is where you might place code to refresh your
     
140.    // directory listing, including the subtree.
     
141.   
     
142.    _tprintf(TEXT("Directory tree (%s) changed.\n"), lpDrive);
     
143. }
     
144. 
     

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这段程序是监控某个目录的io操作的，目前只能实现知道发生了某个事件，但如果要获取详细的参数，比如 “A file was created, renamed, or deleted in the directory.”
  新建的文件名，删除的文件名，这些详细参数，有没有api可以获取到？

bruceteen

得用 ReadDirectoryChangesW 才行

yakczh_cu

回复 2# bruceteen

是在case WAIT_OBJECT_0: 的分支中调用这个api吗？  能否详细指点下

bruceteen

按照MSDN随手写了个例子，但你最好还是自己去google吧

1. #include <windows.h>
   
2. #include <stdio.h>
   
3. #include <locale.h>
   
4. 
   
5. int main( void )
   
6. {
   
7.         setlocale( LC_CTYPE, "" );
   
8. 
   
9.         HANDLE hFile = CreateFileW( L"E:", FILE_LIST_DIRECTORY, FILE_SHARE_DELETE|FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, NULL );
   
10.         if( hFile != INVALID_HANDLE_VALUE )
    
11.         {
    
12.                 char buf[4096] = { 0 };
    
13.                 DWORD ByteReturned;
    
14.                 while( ReadDirectoryChangesW( hFile, buf, sizeof(buf), TRUE, FILE_NOTIFY_CHANGE_FILE_NAME|FILE_NOTIFY_CHANGE_DIR_NAME, &ByteReturned, NULL, NULL ) )
    
15.                 {
    
16.                         for( const FILE_NOTIFY_INFORMATION* pNotify=(FILE_NOTIFY_INFORMATION*)buf; pNotify; pNotify=pNotify->NextEntryOffset==0?NULL:(FILE_NOTIFY_INFORMATION*)((char*)pNotify + pNotify->NextEntryOffset) )
    
17.                         {
    
18.                                 switch( pNotify->Action )
    
19.                                 {
    
20.                                 case FILE_ACTION_ADDED:            wprintf( L"%s", L"ADDED   : " ); break;
    
21.                                 case FILE_ACTION_REMOVED:          wprintf( L"%s", L"REMOVED : " ); break;
    
22.                                 case FILE_ACTION_MODIFIED:         wprintf( L"%s", L"MODIFIED: " ); break;
    
23.                                 case FILE_ACTION_RENAMED_OLD_NAME: wprintf( L"%s", L"OLD NAME: " ); break;
    
24.                                 case FILE_ACTION_RENAMED_NEW_NAME: wprintf( L"%s", L"NEW NAME: " ); break;
    
25.                                 }
    
26.                                 wprintf( L"%.*s\n", pNotify->FileNameLength/sizeof(wchar_t), pNotify->FileName );
    
27.                         }
    
28.                 }
    
29. 
    
30.                 CloseHandle( hFile );
    
31.         }
    
32. }

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