断言失败[：inDictionary：hasExpectedType：nullAllowed：NSJSONSerialization ensureObjectForKey]

Question

我采用箱IOS-SDK-V2（V1.1.0），当我叫我：

[[BoxCocoaSDK sharedSDK].foldersManager folderInfoWithID:BoxAPIFolderIDRoot 
              requestBuilder:nil 
               success:folderSuccess 
               failure:failure]; 

我得到一个说法失败：

*** Assertion failure in +[NSJSONSerialization ensureObjectForKey:inDictionary:hasExpectedType:nullAllowed:], ~/MyApp/Pods/box-ios-sdk-v2/BoxSDK/Categories/NSJSONSerialization+BoxAdditions.m:27 
An uncaught exception was raised 
+[NSJSONSerialization(BoxAdditions) ensureObjectForKey:inDictionary:hasExpectedType:nullAllowed:]: Unexpected JSON null when extracting key modified_at from dictionary { 
    "content_created_at" = "<null>"; 
    "content_modified_at" = "<null>"; 
    "created_at" = "<null>"; 
    "created_by" =  { 
     id = ""; 
     login = ""; 
     name = ""; 
     type = user; 
    }; 
    description = ""; 
    etag = "<null>"; 
    "folder_upload_email" = "<null>"; 
    id = 0; 
    "item_collection" =  { 
     entries =   (
         { 
       etag = 0; 
       id = 1092326452; 
       name = CSS; 
       "sequence_id" = 0; 
       type = folder; 
      }, 
         { 
       etag = 1; 
       id = 680411078; 
       name = New; 
       "sequence_id" = 1; 
       type = folder; 
      }, 
         { 
       etag = 2; 
       id = 8224096128; 
       name = ".apdisk"; 
       "sequence_id" = 2; 
       sha1 = e8389b6e4307a798b0811cabc94144ce381b3312; 
       type = file; 
      } 
     ); 
     limit = 100; 
     offset = 0; 
     order =   (
         { 
       by = type; 
       direction = ASC; 
      }, 
         { 
       by = name; 
       direction = ASC; 
      } 
     ); 
     "total_count" = 3; 
    }; 
    "item_status" = active; 
    "modified_at" = "<null>"; 
    "modified_by" =  { 
     id = 181198661; 
     login = "grigutis@iu.edu"; 
     name = "John Grigutis"; 
     type = user; 
    }; 
    name = "All Files"; 
    "owned_by" =  { 
     id = 181198661; 
     login = "grigutis@iu.edu"; 
     name = "John Grigutis"; 
     type = user; 
    }; 
    parent = "<null>"; 
    "path_collection" =  { 
     entries =   (
     ); 
     "total_count" = 0; 
    }; 
    "purged_at" = "<null>"; 
    "sequence_id" = "<null>"; 
    "shared_link" = "<null>"; 
    size = 289; 
    "trashed_at" = "<null>"; 
    type = folder; 
} 

这是我的帐户（modified_at真的不应该为null）或SDK的问题吗？如果这是我的帐户，我该如何解决这个问题？

Answer 1

我是Box iOS SDK的维护者。感谢您的错误报告！根文件夹是Box上的特殊文件夹。根文件夹是实际上不存在的“虚拟文件夹”（这解释了为什么它们在所有用户帐户中始终具有0的标识）。由于根文件夹（和垃圾文件夹）是虚拟文件夹，因此我们不会跟踪它们的某些元数据，例如modified_at时间戳。

可能为空值根/垃圾文件夹字段列表：

• sequence_id
• ETAG
• created_at
• modified_at
• trashed_at
• purged_at
• content_created_at
• content_modified_at
• shared_link
• 父

我已经把一个补丁，这将抑制这些空值，并将其转换到零。 （我并不想将所有访问器都转换为id返回类型，只是针对根/垃圾文件夹的特殊情况。）https://github.com/box/box-ios-sdk-v2/pull/47

一旦这个提交被合并，我们将会修改一个bug修复版本。

我们应该记录这种边缘情况/特殊情况的行为。我会让我们的文档团队知道。