通过等待任务或访问其异常属性，没有观察到任务的异常 [英] A Task's exception(s) were not observed either by Waiting on the Task or accessing its Exception property

问题描述

这些是我的任务。我应该如何修改它们以防止此错误。我检查了其他类似的线程，但我正在等待并继续。那么这个错误是怎么发生的？

任务的异常没有被等待任务或访问其异常属性所观察到。因此，未知的异常被终结者线程重新抛出。

  var CrawlPage = Task .Factory.StartNew（（）=> 
 {
 return crawlPage（srNewCrawledUrl，srNewCrawledPageId，srMainSiteId）; 
}）; 
 
 var GetLinks = CrawlPage.ContinueWith（resultTask => 
 {
 if（CrawlPage.Result == null）
 {
 return null; 
} 
 else 
 {
 return ReturnLinks（CrawlPage.Result，srNewCrawledUrl，srNewCrawledPageId，srMainSiteId）; 
} 
}）; 
 
 var InsertMainLinks = GetLinks.ContinueWith（resultTask => 
 {
 if（GetLinks.Result == null）
 {
 
 } 
 else 
 {
 instertLinksDatabase（srMainSiteURL，srMainSiteId，GetLinks.Result，srNewCrawledPageId，irCrawlDepth.ToString（））; 
} 
 
}）; 
 
 InsertMainLinks.Wait（）; 
 InsertMainLinks.Dispose（）; 
  

解决方案

您没有处理任何异常。 >

更改此行：

  InsertMainLinks.Wait（）; 
  

TO：

 code> try {
 InsertMainLinks.Wait（）; 
} 
 catch（AggregateException ae）{
 / *你会做什么* / 
} 
  

一般来说：为了防止终结者重新抛出您工作线程中发生的任何未处理的异常，您可以：

等待线程并捕获System.AggregateException，或者只是读取异常属性。

EG：

  Task.Factory.StartNew（（s）=> {
 throw new Exception（ooga booga）; 
}，TaskCreationOptions.None）.ContinueWith（（Task上一个）=> {
 var e = previous.Exception; 
 //做你会用非空异常
}）; 
  

或

  Task.Factory.StartNew（（s）=> {
 throw new Exception（ooga booga）; 
}，TaskCreationOptions.None）.ContinueWith（（以前的任务）=> ; {
 try {
 previous.Wait（）; 
} 
 catch（System.AggregateException ae）{
 // do you you 
} 
}）; 
  

These are my tasks. How should i modify them to prevent this error. I checked the other similar threads but i am using wait and continue with. So how come this error happening?

A Task's exception(s) were not observed either by Waiting on the Task or accessing its Exception property. As a result, the unobserved exception was rethrown by the finalizer thread.

    var CrawlPage = Task.Factory.StartNew(() =>
{
    return crawlPage(srNewCrawledUrl, srNewCrawledPageId, srMainSiteId);
});

var GetLinks = CrawlPage.ContinueWith(resultTask =>
{
    if (CrawlPage.Result == null)
    {
        return null;
    }
    else
    {
        return ReturnLinks(CrawlPage.Result, srNewCrawledUrl, srNewCrawledPageId, srMainSiteId);
    }
});

var InsertMainLinks = GetLinks.ContinueWith(resultTask =>
{
    if (GetLinks.Result == null)
    {

    }
    else
    {
        instertLinksDatabase(srMainSiteURL, srMainSiteId, GetLinks.Result, srNewCrawledPageId, irCrawlDepth.ToString());
    }

});

InsertMainLinks.Wait();
InsertMainLinks.Dispose();

解决方案

You're not handling any exception.

Change this line:

InsertMainLinks.Wait();

TO:

try { 
    InsertMainLinks.Wait(); 
}
catch (AggregateException ae) { 
    /* Do what you will */ 
}

In general: to prevent the finalizer from re-throwing any unhandled exceptions originating in your worker thread, you can either:

Wait on the thread and catch System.AggregateException, or just read the exception property.

EG:

Task.Factory.StartNew((s) => {      
    throw new Exception("ooga booga");  
}, TaskCreationOptions.None).ContinueWith((Task previous) => {  
    var e=previous.Exception;
    // Do what you will with non-null exception
});

OR

Task.Factory.StartNew((s) => {      
    throw new Exception("ooga booga");  
}, TaskCreationOptions.None).ContinueWith((Task previous) => {      
    try {
        previous.Wait();
    }
    catch (System.AggregateException ae) {
        // Do what you will
    }
});

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