用户清空垃圾箱时收到通知？

Question

How would my cocoa app receive a notification when the user empties their trash. This is what I have so far:

 NSNotificationCenter *notCenter = [[NSWorkspace sharedWorkspace]
                                       notificationCenter];
    AppDelegate *mainController = [[AppDelegate alloc] init];

    [notCenter addObserver:mainController
                  selector:@selector(handleTrashEmpty)
                      name:NSWorkspaceRecycleOperation object:nil];

But when nothing shows up when the user empties their trash. Any ideas why this code is not working?

Answer 1

1st way:

You can use UKKQueue to watch file change (empty thrash) notifications:

http://www.cocoadev.com/index.pl?UKKQueue

2nd way:

Keep on checking with a timer if the [folderList count]==0, means trash is emptied.

NSError *error=nil;
NSString *path=[NSHomeDirectory() stringByAppendingPathComponent:@".Trash"];
NSArray *folderList=[[NSFileManager defaultManager] contentsOfDirectoryAtPath:path error:&error];

3rd way:

watch ~/.Trash, "com.apple.carbon.core.DirectoryNotification" is posted when the trash is emptied.

Answer 2

NSWorkspaceRecycleOperation is not a notification at all but a file operation constant passed to performFileOperation:source:destination:files:tag:

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you use the FSEvents api to monitor /.Trashes. Here's some sample code: http://subversion.assembla.com/svn/quotamonitormenu/QuotaMonitorMenu/branches/QuotaMonitorMenuFaculty/StatusItemController.m