HTTP 请求异常 Xamarin 表单

Question

我正在使用 HttpClient 和 PostAsync 向我的服务器发送一个大型视频文件（平均文件大小为 50mb）。我遇到了一个异常（请参阅下文了解完整的异常详情）。我发现一篇文章说可以处理的最大文件大小为 1mb 或更小，这是真的吗？如果是这样，我怎样才能增加最大文件大小？

{System.Net.Http.HttpRequestException: 发送请求时出错---> System.IO.IOException: 写入请求时出错---> System.Net.Sockets.SocketException: 套接字已关闭 在 System.Net.WebConnection.EndWrite（System.Net.HttpWebRequest 请求，System.Boolean throwOnError，System.IAsyncResult 结果）[0x000cc] 在 ：0 在 System.Net.WebConnectionStream.WriteAsyncCB (System.IAsyncResult r) [0x00013] 在 :0 --- 内部异常堆栈跟踪结束 --- 在 System.Net.WebConnectionStream.EndWrite (System.IAsyncResult r) [0x000b8] 在 :0 在 System.IO.Stream+c.b__53_1（System.IO.Stream 流，System.IAsyncResult asyncResult）[0x00000] in :0 在（包装器委托调用）System.Func3[System.IO.Stream,System.IAsyncResult,System.Threading.Tasks.VoidTaskResult].invoke_TResult_T1_T2(System.IO.Stream,System.IAsyncResult) at System.Threading.Tasks.TaskFactory1+FromAsyncTrimPromise1[TResult,TInstance].Complete (TInstance thisRef, System.Func3[T1,T2,TResult] endMethod, System.IAsyncResult asyncResult, System.Boolean requiresSynchronization) [0x00000] in :0 --- 从之前抛出异常的位置结束堆栈跟踪 --- 在 System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] 在：0 在 System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task 任务) [0x0003e] in :0 在 System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task 任务) [0x00028] in :0 在 System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task 任务) [0x00008] in :0 在 System.Runtime.CompilerServices.ConfiguredTaskAwaitable+ConfiguredTaskAwaiter.GetResult () [0x00000] 在：0 在 System.Net.Http.HttpClientHandler+d__64.MoveNext () [0x0036e] in :0 --- 内部异常堆栈跟踪结束 --- 在 System.Net.Http.HttpClientHandler+d__64.MoveNext () [0x00489] 在：0 --- 从之前抛出异常的位置结束堆栈跟踪 --- 在 System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] 在：0 在 System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task 任务) [0x0003e] in :0 在 System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task 任务) [0x00028] in :0 在 System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task 任务) [0x00008] in :0 在 System.Runtime.CompilerServices.ConfiguredTaskAwaitable1+ConfiguredTaskAwaiter[TResult].GetResult () [0x00000] in <df077aeeed724748974ac70c763795f3>:0 at System.Net.Http.HttpClient+<SendAsyncWorker>d__49.MoveNext () [0x000ca] in <e4f3fb4cf2054f718c1099b587ec6f1e>:0 --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in <df077aeeed724748974ac70c763795f3>:0 at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x0003e] in <df077aeeed724748974ac70c763795f3>:0 at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x00028] in <df077aeeed724748974ac70c763795f3>:0 at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x00008] in <df077aeeed724748974ac70c763795f3>:0 at System.Runtime.CompilerServices.TaskAwaiter1[TResult].GetResult () [0x00000] in :0 在 C:\Users\lawre\source\repos\TBSMobile\TBSMobile\TBSMobile\View\MainMenu.xaml.cs:1088 中的 TBSMobile.View.MainMenu+d__22.MoveNext () [0x00b96] }

byte[] crVideoData;

if (!string.IsNullOrEmpty(crvideo))
{
    crVideoData = File.ReadAllBytes(crvideo);
}
else
{
    crVideoData = null;
}

try
{
    if (!string.IsNullOrEmpty(crvideo))
    {
        var vidlink = "http://" + ipaddress + Constants.requestUrl + "Host=" + host + "&Database=" + database + "&Contact=" + contact + "&Request=Lqr9fy";
        string vidcontentType = "application/json";
        JObject vidjson = new JObject
        {
           { "CAFNo", crcafNo },
           { "CAFDate", crcafDate },
           { "Video", crVideoData }
        };

        HttpClient vidclient = new HttpClient();
        var vidresponse = await vidclient.PostAsync(vidlink, new StringContent(vidjson.ToString(), Encoding.UTF8, vidcontentType));

        if (vidresponse.IsSuccessStatusCode)
        {
            await conn.QueryAsync<CAFTable>("UPDATE tblCaf SET LastSync = ? WHERE CAFNo = ?", DateTime.Parse(current_datetime), crcafNo);
        }
    }
    else
    {
         await conn.QueryAsync<CAFTable>("UPDATE tblCaf SET LastSync = ? WHERE CAFNo = ?", DateTime.Parse(current_datetime), crcafNo);
    }
}
catch(Exception ex)
{
    Crashes.TrackError(ex);
}

Answer 1

如果您使用 api 将上传的视频保存在服务器中，您的最大请求长度可能小于您上传的视频大小。如果要上传大尺寸视频，请在 webconfig 文件中增加最大请求长度。这是在 web api 项目中增加最大请求长度的示例代码。

  <httpRuntime targetFramework="4.5.2" maxRequestLength="15200" />