iOS 任意类型数据转换字符串

 //转换数据类型：

  NSError *parseError = nil;

   NSData  *jsonData = [NSJSONSerialization  dataWithJSONObject:responseObject options:NSJSONWritingPrettyPrinted error:&parseError];

  NSString* jsonStr = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];

  NSLog(@"respone data :%@",jsonStr);