使用 Dio/bloc Flutter 处理错误

Question

我需要一种很好的方法来处理我在使用 Dio 请求时的错误。 我可以在一个类中做到这一点并通过 dio 请求抛出它吗？ 它应该返回一个带有错误的响应。

Answer 1

我在这里发布我的通用网络集团，它可以在任何时间、任何地点重复使用。 此外，它使用 dio 使用 API 存储库 ， 异常和错误处理.

class NetworkBloc extends Bloc<NetworkEvent, NetworkState> {
NetworkBloc() : super(NetworkRequestInitial());
@override
Stream<NetworkState> mapEventToState(
NetworkEvent event,
) async* {
yield NetworkRequestInitiated();
if (event is NetworkCallEvent) {
RequestType requestType = event.requestType;
if (requestType == RequestType.GET) {
yield* fetchData(event);
} else if (requestType == RequestType.POST) {
yield* uploadDataAndStoreResult(event);
}
}
}
Stream<NetworkState> fetchData(NetworkCallEvent event) async* {
Response response;
try {
yield NetworkRequestLoading();
response =
await event.apiRepository.sendGetRequest(event.url, event.request);
if (response.statusCode == 200) {
yield NetworkRequestLoaded(response: response);
} else {
Map jsonResponse = jsonDecode(response.data);
yield NetworkRequestFailure(message: jsonResponse['message']);
}
} catch (e) {
yield NetworkRequestFailure(
message: NetworkUtils.getErrorMessageAccordingToError(e));
}
}
Stream<NetworkState> uploadDataAndStoreResult(NetworkCallEvent event) async* {
Response response;
try {
yield NetworkRequestLoading();
if (event.request != null) {
if (event.isHeadersNeeded) {
response = await event.apiRepository.sendPostRequestWithHeader(
event.url,
request: event.request,
);
} else {
response = await event.apiRepository.sendPostRequest(
event.url,
event.request,
);
}
} else {
response = await event.apiRepository
.sendPostRequestWithoutBodyParameters(event.url);
}
if (response.statusCode == 200) {
saveDataAccordingToCacheMechanism(event, response);
yield NetworkRequestLoaded(response: response);
} else {
Map jsonResponse = jsonDecode(response.data);
yield NetworkRequestFailure(message: jsonResponse['message']);
}
} catch (e) {
yield NetworkRequestFailure(
message: NetworkUtils.getErrorMessageAccordingToError(e));
}
}
void saveDataAccordingToCacheMechanism(
NetworkCallEvent event, Response response) async {
if (event.cacheMechanism == CacheMechanism.SharePreferences) {
Hive.box(ConstUtils.dbName)
.put(event.keyForSharedPreferences, response.data.toString());
} else if (event.cacheMechanism == CacheMechanism.Database) {}
}
}

我还添加了状态和事件，以使其更易于理解。

class NetworkCallEvent extends NetworkEvent {
final String request;
final dynamic url;
final RequestType requestType;
final CacheMechanism cacheMechanism;
final String keyForSharedPreferences;
final APIRepository apiRepository;
final bool isHeadersNeeded;
NetworkCallEvent(
{@required this.url,
this.request,
this.isHeadersNeeded = false,
@required this.requestType,
@required this.apiRepository,
@required this.cacheMechanism,
this.keyForSharedPreferences});
@override
List<Object> get props => [
this.url,
this.request,
this.requestType,
this.cacheMechanism,
this.keyForSharedPreferences,
this.apiRepository
];
}

Network_states：

class NetworkRequestInitial extends NetworkState {}
class NetworkRequestInitiated extends NetworkState {}
class NetworkRequestLoading extends NetworkState {}
class NetworkRequestLoaded extends NetworkState {
final dynamic response;
NetworkRequestLoaded({this.response});
@override
List<Object> get props => [this.response];
}
class NetworkRequestFailure extends NetworkState {
final String message;
NetworkRequestFailure({this.message});
@override
List<Object> get props => [this.message];
}

您可以轻松地在 JSON 中发送请求并动态获取响应，您可以使用json.decode()将其转换为适当的对象。