iOS Cocoa NSArrayI 长度] : unrecognized selector sent to instance

Question

我正在尝试确定导致此错误的原因:

2014-06-08 20:40:44.076 Database[8656:70b] -[__NSArrayI length]: unrecognized selector sent to instance 0x8a44050

这是代码。

NSDictionary* json = [NSJSONSerialization JSONObjectWithData:responseData options:0 error:&error];

这是发生错误的断点:NSLog([json allKeys]);

用作输入的 JSON 示例:

{"1":{"key":"1","contentONE":"aaa","contentTWO":"testing"},"2":{"key":"2","contentONE":"bbb","contentTWO":null},"3":{"key":"3","contentONE":"ccc","contentTWO":"testing"}}

Answer 1

[json allKeys] 返回一个 NSArray，而 NSLog 需要一个格式化字符串。试试这个:

NSLog(@"%@", [json allKeys]);