unhandled cancel Exception

[zhengbomo]

after cancel the request by token, dio has also occurred an unhandled Exception like this

here is my code

import 'package:dio/dio.dart';

...

void _testDio() async {
  CancelToken token = CancelToken();
  var url = "https://github.com/flutterchina12121/dio";

  Future.delayed(const Duration(milliseconds: 0), () async {
    try {
      Response response = await Dio().get(url, cancelToken: token);
      if (response.statusCode == 200) {
        print("request success");
      } else {
        print("request failed");
      }
    } catch (e) {
      print("request failed with exception");
    }
  });

  Future.delayed(const Duration(milliseconds: 250), () {
    print("manual cancel");
    if (!token.isCancelled) {
      token.cancel();
    }
  });
}

when i call _testDio frequently, the Exception occurred

version:

• flutter: 1.5.4-hotfix.2
• platform: iOS
• dart: 2.3.0

[wendux]

Not bug! Dio will throw a DioError error with DioErrorType.CANCEL when request is cancelled.

[zhengbomo]

Not bug! Dio will throw a DioError error with DioErrorType.CANCEL when request is cancelled.

@wendux is there any idea to fix it?

[wendux]

you can refer to https://github.com/flutterchina/dio/blob/master/example/cancel_request.dart

[micsanbr]

dio.download(url, filePath, cancelToken: _cancelToken, /.../) still throws an exception when using catchError() after cancelling with the token.

the workaround seems to be a try/catch using DioError
try {} on DioError catch (exception) { print("something"); }

[ganeshrvel]

@micsan13br both
catchError and try {} on DioError catch (exception) { print("something"); } doesn't seem to work.

[rvn9]

what to do if i only want to cancel once ? lets say im donwloading something and user want to manual cancel that donwload, when im calling token.cancel() for the next request auto exception, must keep making diffrent cancel token for each req ?

[Sp4Rx]

if you want to cancel once assign a new cancelToken after the first request has been canceled.

    CancelToken _cancelToken = CancelToken();
   Response response = await _dio.get(
      url,
      options: Options(headers: headers),
      cancelToken: _cancelToken,
    );

    //After some operation
    _cancelToken.cancel('Logged out');
    //Some operation
    _cancelToken = CancelToken();

[testOccu16]

you can refer to https://github.com/flutterchina/dio/blob/master/example/cancel_request.dart

404 - Page Not Found

[choijaegwon]

취소처리될때 에러 반환 하지 않는방법

} catch (e) {
    if (e is DioException && e.type == DioExceptionType.cancel) {
        // 필요시 취소처리 로직추가
        return;
    }

    // 에러처리 로직
}