问UIDocumentStateChangedNotification检测删除项目

EN

[[NSNotificationCenter defaultCenter]
        addObserver:self
        selector:@selector(itemHasChanged:)
        name:UIDocumentStateChangedNotification
        object:nil];

-(void) itemHasChanged:(id)sender {
    UIDocument *itemDoc = [sender object]; 

    if ([itemDoc documentState] == UIDocumentStateSavingError) {
      // your code to handle a deleted document goes here
      // in my case I remove that object from my array of current objects.
    }
}