System.Net.WebException 未在 Windows Phone 8 上截获
本文关键字:Phone Windows Net WebException 未在 System | 更新日期: 2023-09-27 18:33:23
我正在尝试使用RestSharp调用Web服务(这必须为WP8以后完成)。
这是我触发的方法:
private async void postRest()
{
string getSyncService = "MyService";
var client = new RestClient(ip);
var request = new RestRequest(getSyncService, Method.POST);
request.RequestFormat = DataFormat.Json;
JsonObject jsonGenericRequest = new JsonObject();
jsonGenericRequest.Add("companyid", "123");
jsonGenericRequest.Add("token", "123"); ...
request.AddParameter("GenMobileRequest", jsonGenericRequest);
request.AddHeader("Access-Control-Allow-Methods", "POST");
request.AddHeader("Content-Type", "application/json; charset=utf-8");
request.AddHeader("Accept", "application/json");
try
{
// easy async support
client.ExecuteAsync(request, response =>
{
Console.WriteLine("response content: " + response.Content);
if (response.ResponseStatus == ResponseStatus.Completed)
{
MessageBox.Show("errorMsg: " + response.ErrorMessage);
}
});
}
catch (System.Net.WebException ex)
{
MessageBox.Show(" " + ex.InnerException.ToString());
}
}
在我的日志上,我收到此异常:
类型为"System.Net.WebException"的异常发生在 System.Windows.ni.dll 并且在托管/本机之前未处理 边界
我什至无法在我的处理程序中保留任何信息
// Code to execute on Unhandled Exceptions
private void Application_UnhandledException(object sender, ApplicationUnhandledExceptionEventArgs e)
{
Console.WriteLine(" ---Application_UnhandledException---");
if (Debugger.IsAttached)
{
// An unhandled exception has occurred; break into the debugger
Debugger.Break();
}
}
如何获取有关问题的更多信息?
有关调用 WS 的正确方式的任何其他信息将不胜感激。
谢谢
来源:https://blogs.msdn.microsoft.com/ptorr/2014/12/10/async-exceptions-in-c/
using System;
using System.Runtime.CompilerServices;
using System.Threading;
using System.Threading.Tasks;
namespace AsyncAndExceptions
{
class Program
{
static void Main(string[] args)
{
AppDomain.CurrentDomain.UnhandledException += (s, e) => Log("*** Crash! ***", "UnhandledException");
TaskScheduler.UnobservedTaskException += (s, e) => Log("*** Crash! ***", "UnobservedTaskException");
RunTests();
// Let async tasks complete...
Thread.Sleep(500);
GC.Collect(3, GCCollectionMode.Forced, true);
}
private static async Task RunTests()
{
try
{
// crash
// _1_VoidNoWait();
// crash
// _2_AsyncVoidAwait();
// OK
// _3_AsyncVoidAwaitWithTry();
// crash - no await
// _4_TaskNoWait();
// crash - no await
// _5_TaskAwait();
// OK
// await _4_TaskNoWait();
// OK
// await _5_TaskAwait();
}
catch (Exception ex) { Log("Exception handled OK"); }
// crash - no try
// await _4_TaskNoWait();
// crash - no try
// await _5_TaskAwait();
}
// Unsafe
static void _1_VoidNoWait()
{
ThrowAsync();
}
// Unsafe
static async void _2_AsyncVoidAwait()
{
await ThrowAsync();
}
// Safe
static async void _3_AsyncVoidAwaitWithTry()
{
try { await ThrowAsync(); }
catch (Exception ex) { Log("Exception handled OK"); }
}
// Safe only if caller uses await (or Result) inside a try
static Task _4_TaskNoWait()
{
return ThrowAsync();
}
// Safe only if caller uses await (or Result) inside a try
static async Task _5_TaskAwait()
{
await ThrowAsync();
}
// Helper that sets an exception asnychronously
static Task ThrowAsync()
{
TaskCompletionSource tcs = new TaskCompletionSource();
ThreadPool.QueueUserWorkItem(_ => tcs.SetException(new Exception("ThrowAsync")));
return tcs.Task;
}
internal static void Log(string message, [CallerMemberName] string caller = "")
{
Console.WriteLine("{0}: {1}", caller, message);
}
}
}
原因是异步
void 方法的异常无法通过 catch 捕获。
异步 void 方法具有不同的错误处理语义。当一个 异常从异步任务或异步任务方法中抛出,即 捕获异常并将其放置在任务对象上。具有异步空 方法,则没有 Task 对象,因此从 异步无效方法将直接在 同步异步 void 方法时处于活动状态的上下文 开始
错误是需要将异步 void 方法更改为异步任务方法。
源在 msdn 上 这里 和 这里