Question

我正在尝试使用一个列表（自定义类型），但出现错误。在这两行上。 List和getData在VSCode中显示为红色，类似错误。

 Future List<UserVideo> getData() async {
    List<UserVideo> list = [];

这是我得到的错误。

This function has a return type of 'Future<dynamic>', but doesn't end with a return statement.
Try adding a return statement, or changing the return type to 'void'.dartmissing_re

这是代码。

class UserVideo {
  final String url;
  final String image;
  final String desc;

  UserVideo({
    this.url: mockVideo,
    this.image: mockImage,
    this.desc,
  });

 Future List<UserVideo> getData() async {
    List<UserVideo> list = [];
    try {
      var deviceid = '123';
      var dtgUid = '100';

      var nodata;

      var bodyss = {
        "uid": dtgUid,
        "deviceid": deviceid,

      };

      var url = 'http://192.168.100.4:8080/videos/get-data.php';

      // Starting Web API Call.
      var response = await http
          .post(url, body: json.encode(bodyss))
          .timeout(Duration(seconds: 5), onTimeout: () {
        return null;
      });
      if (response.statusCode == 200) {
        final data = StreamingFromJson(response.body);
        if (data.count == null) {
          count = 0;
        } else {
          count = data.count;
        }
        if (data.content.length > 0 && data.content[0].name != 'Empty') {
          for (var i in data.content) {
            list.add(UserVideo(image: i.thumbnail, url: i.video, desc: i.title));
          }
        } else {
          nodata = 'No Record Found';
        }
        print(list.length);
      }
    } catch (e) {
      print("Exception Caught: $e");
    }
    return list;
  }

还有另外几个错误，如下所示。

在列表中

Name non-constant identifiers using lowerCamelCase.dartnon_constant_identifier_names

This function has a return type of 'Future<dynamic>', but doesn't end with a return statement.
Try adding a return statement, or changing the return type to 'void'.dartmissing_return

Functions must have an explicit list of parameters.
Try adding a parameter list.dart(missing_function_parameters)

关于getData函数

A function body must be provided.
Try adding a function body.

修改

JayDev帮助我解决了该错误，但现在又给了我另一个错误。

当我尝试使用getData（）函数时。如下所示。

List<UserVideo> videoDataList = [];

videoDataList = UserVideo.getData();

我收到错误消息。

A value of type 'Future<List<UserVideo>>' can't be assigned to a variable of type 'List<UserVideo>'.
Try changing the type of the variable, or casting the right-hand type to 'List<UserVideo>'.

Answer 1

我相信您的方法签名是错误的。您应该将想要从Future返回的类型放在大括号后，即

Future<List<UserVideo>> getData() async {
   ...
}

flutter：此函数的返回类型为'Future <dynamic>'，但不以return语句结尾

1 个答案: