ios端返回106 指针

Error Domain=AVOS Cloud Error Domain Code=106 "Malformed pointer. Pointers must be arrays of a classname and an object id." UserInfo={error=Malformed pointer. Pointers must be arrays of a classname and an object id., NSLocalizedDescription=Malformed pointer. Pointers must be arrays of a classname and an object id., code=106}

NSDictionary *dic = @{@"__type":@"Pointer",@"className":@"Sort",@"objectId":weakSelf.productModel.sortModel.sortId};
[post setObject:[weakSelf DataTOjsonString:dic] forKey:@"sort"];
这样设置指针不对吗？