我有一个问题，我正在使用HttpClient在异步任务中从API提取大型JSON内容。当应用程序在后台执行请求时锁定设备屏幕时，会发生问题。如果我再次打开该应用程序，它将崩溃（SIGABRT：该套接字未连接）
这是github上的项目： https://github.com/aproram/httpclient-bug
为了复制问题，请按照以下步骤精确复制问题： -确保应用已终止且未在后台运行 -打开应用 -按下主屏幕按钮。 锁电话 -解锁电话 -再次打开该应用程序，它将崩溃。
崩溃堆栈跟踪（使用AppHockey）：
Socket.EndReceive (System.IAsyncResult asyncResult)
NetworkStream.EndRead (System.IAsyncResult asyncResult)
NetworkStream.EndRead (System.IAsyncResult asyncResult)
Stream+<>c.<BeginEndReadAsync>b__45_1 (System.IO.Stream stream, System.IAsyncResult asyncResult)
TaskFactory`1+FromAsyncTrimPromise`1[TResult,TInstance].Complete (TInstance thisRef, System.Func`3[T1,T2,TResult] endMethod, System.IAsyncResult asyncResult, System.Boolean requiresSynchronization)
MobileAuthenticatedStream.InnerRead (System.Boolean sync, System.Int32 requestedSize, System.Threading.CancellationToken cancellationToken)
AsyncProtocolRequest.InnerRead (System.Threading.CancellationToken cancellationToken)
AsyncProtocolRequest.ProcessOperation (System.Threading.CancellationToken cancellationToken)
AsyncProtocolRequest.StartOperation (System.Threading.CancellationToken cancellationToken)
MobileAuthenticatedStream.StartOperation (Mono.Net.Security.MobileAuthenticatedStream+OperationType type, Mono.Net.Security.AsyncProtocolRequest asyncRequest, System.Threading.CancellationToken cancellationToken)
BufferedReadStream.ProcessReadAsync (System.Byte[] buffer, System.Int32 offset, System.Int32 size, System.Threading.CancellationToken cancellationToken)
WebReadStream.ReadAsync (System.Byte[] buffer, System.Int32 offset, System.Int32 size, System.Threading.CancellationToken cancellationToken)
FixedSizeReadStream.ProcessReadAsync (System.Byte[] buffer, System.Int32 offset, System.Int32 size, System.Threading.CancellationToken cancellationToken)
WebReadStream.ReadAsync (System.Byte[] buffer, System.Int32 offset, System.Int32 size, System.Threading.CancellationToken cancellationToken)
HttpWebRequest.RunWithTimeoutWorker[T] (System.Threading.Tasks.Task`1[TResult] workerTask, System.Int32 timeout, System.Action abort, System.Func`1[TResult] aborted, System.Threading.CancellationTokenSource cts)
WebResponseStream.ReadAsync (System.Byte[] buffer, System.Int32 offset, System.Int32 count, System.Threading.CancellationToken cancellationToken)
Stream.CopyToAsyncInternal (System.IO.Stream destination, System.Int32 bufferSize, System.Threading.CancellationToken cancellationToken)
HttpContent.LoadIntoBufferAsync (System.Int64 maxBufferSize)
HttpClient.SendAsyncWorker (System.Net.Http.HttpRequestMessage request, System.Net.Http.HttpCompletionOption completionOption, System.Threading.CancellationToken cancellationToken)
ViewController.FetchtheJSON ()
AsyncMethodBuilderCore+<>c.<ThrowAsync>b__7_0 (System.Object state)
NSAsyncSynchronizationContextDispatcher.Apply ()
(wrapper managed-to-native) UIKit.UIApplication.UIApplicationMain(int,string[],intptr,intptr)
UIApplication.Main (System.String[] args, System.IntPtr principal, System.IntPtr delegate)
UIApplication.Main (System.String[] args, System.String principalClassName, System.String delegateClassName)
Application.Main (System.String[] args)
不确定我应该做些什么。 谢谢！
答案 0 :(得分：0)
由于请求超时，您只需要添加空检查。
它不监听响应，因此返回null。您可以执行以下操作：
Date sulfate nitrate ID
1 2001-01-01 NA NA 2
2 2001-01-02 NA NA 2
3 2001-01-03 NA NA 2
4 2001-01-04 NA NA 2
5 2001-01-05 NA NA 2
6 2001-01-06 NA NA 2
7 2001-01-07 NA NA 2
8 2001-01-08 NA NA 2
9 2001-01-09 NA NA 2
10 2001-01-10 NA NA 2
11 2001-01-11 NA NA 2
12 2001-01-12 NA NA 2
13 2001-01-13 NA NA 2
14 2001-01-14 NA NA 2
15 2001-01-15 NA NA 2
16 2001-01-16 NA NA 2
17 2001-01-17 NA NA 2
18 2001-01-18 NA NA 2
19 2001-01-19 2.30 0.699 2
20 2001-01-20 NA NA 2
21 2001-01-21 NA NA 2
22 2001-01-22 NA NA 2
23 2001-01-23 NA NA 2
24 2001-01-24 NA NA 2
25 2001-01-25 2.19 4.970 2
您的崩溃应该消失了。