当一个UIDocument被关闭时，它还能再次关闭吗？即使它的documentState在重新打开后是UIDocumentStateNormal？请帮帮我。非常感谢![documentopenWithCompletionHandler:^(BOOLsuccess){if(success){[documentcloseWithCompletionHandler:^(BOOLsuccess){if(success){[documentopenWithCompletionHandler:^(BOOLsuccess){if(success){NSLog(@"%d",document.docum