把JsonObject中的字段名转成大写

/// <summary>
/// 把JsonObject中的字段名转成大写
/// </summary>
/// <param name="obj"></param>
/// <returns></returns>
public static JsonObject ToUpper(this JsonObject obj)
{
    JsonObject obj_new = new JsonObject();
    foreach (string item in obj.Names)
    {
        obj_new.Add(item.ToUpper(), obj[item]);
    }
    return obj_new;
}