// 将字典或者数组转化为JSON串

- (NSData *)toJSONData:(id)theData

{

NSError *error = nil;

NSData *jsonData = [NSJSONSerialization dataWithJSONObject:theData

options:NSJSONWritingPrettyPrinted

error:&error];

if ([jsonData length] != 0 && error == nil)

{

return jsonData;

}

else

{

return nil;

}

}

// 将JSON串转化为字典或者数组

- (id)toArrayOrNSDictionary:(NSData *)jsonData

{

NSError *error = nil;

id jsonObject = [NSJSONSerialization JSONObjectWithData:jsonData

options:NSJSONReadingAllowFragments

error:&error];

if (jsonObject != nil && error == nil)

{

return jsonObject;

}

else

{

// 解析错误

return nil;

}

}