从父任务引发异常时停止Continuation Task

本文关键字：Continuation Task 异常 任务 | 更新日期: 2023-09-27 18:27:36

如果在并行循环中抛出期望，我想确保继续任务不会发生

 var parent = tf.StartNew(() =>
    Parallel.ForEach(QuestionsLangConstants.questionLangs.Values, (i, state) =>
          {
             try
               {
                 qrepo.UploadQuestions(QWorkBook.Worksheets[i.QSheet],
                 QWorkBook.Worksheets[i.QTranslationSheet], i, prog);
               }
             catch (Exception ex)
               {
                 context.Dispose();
                 state.Break();
                //make sure the execution fails  
               }
          }));
var finalTast = parent.ContinueWith(i =>
            {
                if (context != null)
                {
                    DialogResult result = 
     MessageBox.Show("Do You Want to Commit the Questions?", "Save to DB",
      MessageBoxButtons.OKCancel, MessageBoxIcon.Question);
                    if (result.Equals(DialogResult.OK))
                    {
                       //Do Stuff here
                    }
                    else
                    {
                        return;
                    }
                }
            });

从父任务引发异常时停止Continuation Task

您需要使用ContinueWith重载来接收TaskContinuationOptions并允许执行程序弹出

 var parent = tf.StartNew(() =>
    Parallel.ForEach(QuestionsLangConstants.questionLangs.Values, (i, state) =>
          {
             try
               {
                 qrepo.UploadQuestions(QWorkBook.Worksheets[i.QSheet],
                 QWorkBook.Worksheets[i.QTranslationSheet], i, prog);
               }
             catch (Exception ex)
               {
                 context.Dispose();
                 state.Break();
                //make sure the execution fails  
                throw; //<-- This line was added to stop the continuation task.
               }
          }));
var finalTast = parent.ContinueWith(i =>
            {
               //...
            }, TaskContinuationOptions.OnlyOnRanToCompletion);

不要吞下异常，只对未出现故障的运行continue

var parent = tf.StartNew(() =>
                        Parallel.ForEach(QuestionsLangConstants.questionLangs.Values, (i, state) =>
                        {
                            try
                            {
                                qrepo.UploadQuestions(QWorkBook.Worksheets[i.QSheet], QWorkBook.Worksheets[i.QTranslationSheet], i, prog);
                            }
                           catch (Exception ex)
                           {
                              context.Dispose();
                                state.Break();
                             //make sure the execution fails
                             throw;
                            }
                        }));
var finalTast = parent.ContinueWith(i =>
            {
                if (context != null)
                {
                    DialogResult result = MessageBox.Show("Do You Want to Commit the Questions?", "Save to DB", MessageBoxButtons.OKCancel, MessageBoxIcon.Question);
                    if (result.Equals(DialogResult.OK))
                    {
                       //Do Stuff here
                    }
                    else
                    {
                        return;
                    }
                }
        }, TaskContinuationOptions.NotOnFaulted);
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