graphql_flutter -已从pub.dev页面复制代码-仍出现错误

Question

我从graphql_flutter pub.dev页面复制了这段代码，但当我将鼠标悬停在构建器上时，仍然得到这个错误。我所做的只是放入我的查询中，并在构建器中更改了与我的查询相关的一些值。

Error - The argument type 'StatelessWidget Function(QueryResult, {Future Function(FetchMoreOptions) fetchMore, void Function() refetch})' can't be assigned to the parameter type 'Widget Function(QueryResult, {Future Function(FetchMoreOptions)? fetchMore, Future<QueryResult?> Function()? refetch})'.

  final String _query = """
    query {
      users {
          id
          name
          email
      }
  } """;
  @override
  Widget build(BuildContext context) {    
    return Query(
      options: QueryOptions(
        document: gql(_query), // this is the query string you just created
        pollInterval: Duration(seconds: 10),
      ),
      builder: (QueryResult result, {VoidCallback refetch, FetchMore fetchMore}) {
        if (result.hasException) {
          return Text(result.exception.toString());
        }

        if (result.isLoading) {
          return Text('Loading');
        }
        List repositories = result.data['users'];
        return ListView.builder(
            itemCount: repositories.length,
            itemBuilder: (context, index) {
              final repository = repositories[index];
              return Text(repository['name']);
            });
      },
    );
  }
}```

Answer 1

builder: (QueryResult result, {
                  Future<QueryResult> Function(FetchMoreOptions)? fetchMore,
                  Future<QueryResult?> Function()? refetch,
                }) {

更新构建器函数语法以匹配“参数类型”是可行的。