抛出异常时,C# Backgroundwork 不调用 e.Error

C# Backgroundwork does not call e.Error when exception is thrown

我有一个后台工作人员:

private readonly BackgroundWorker _importWorker = new BackgroundWorker() { WorkerReportsProgress = true };

在我的构造函数中我这样做:

_importWorker.DoWork += _importWorker_DoWork;
_importWorker.ProgressChanged += _importWorker_ProgressChanged;
_importWorker.RunWorkerCompleted += _importWorker_RunWorkerCompleted;

以下是代表们:

private void _importWorker_DoWork(object sender, DoWorkEventArgs e)
    {
        var args = (object[]) e.Argument;
        var walletColumnName = (string) args[0];
        var fundColumnName = (string) args[1];
        var isinColumName = (string) args[2];
        var marketValueDirtyColumnName = (string) args[3];
        var seperator = (string) args[4];
        var importFilePath = (string) args[5];
        var importFile = Path.GetFileName(importFilePath);

        var onePercent = 100.0 / File.ReadLines(importFilePath).Count();
        var totalPercentage = 0.0;


        var parser = new TextFieldParser(importFilePath);
        parser.TextFieldType = FieldType.Delimited;
        parser.SetDelimiters(seperator);

        //Read colum indexes on the first line
        var fields = parser.ReadFields();
        var walletColumnIndex = Array.IndexOf(fields, walletColumnName);
        var fundColomnIndex = Array.IndexOf(fields, fundColumnName);
        var isinColumnIndex = Array.IndexOf(fields, isinColumName);
        var marketValueDirtyColumnIndex = Array.IndexOf(fields, marketValueDirtyColumnName);

        if (walletColumnIndex == -1 || fundColomnIndex == -1 || isinColumnIndex == -1 ||
            marketValueDirtyColumnIndex == -1)
        {
            throw new ArgumentException("Eén of meerdere kolommen niet gevonden in " + importFile);
        }

        //TODO

        e.Result = importFile;     
    }

    private void _importWorker_ProgressChanged(object sender, ProgressChangedEventArgs e)
    {
        Progress = e.ProgressPercentage;
    }

    private void _importWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
    {
        if (e.Error != null)
        {
            Messenger.Default.Send(e.Error);
        }

        else if (e.Result != null)
        {
            PenultimateImportFileName = LastImportFileName;
            PenultimateImportDate = LastImportDate;               
            LastImportFileName = e.Result.ToString();
            LastImportDate = ImportDate;
            _dataContainer.UpdateImportSettings(_importSettings);
        }

        Progress = 100;
        IsBusy = false;
    }

抛出异常时,backroundworker 不会调用e.Error,而是应用程序崩溃。这是否正常,如何解决?我读到 E.Error 在 dowork 中抛出未处理的异常时自动调用。

我是这样称呼后台工作人员的:

_importWorker.RunWorkerAsync(new object[] {WalletColumnName, FundColumnName, IsinColumName, MarketValueDirtyColumnName, Seperator, s});

编辑

调试器确实中断并抛出了我在代码中抛出的异常:

System.ArgumentException was unhandled by user code
  HResult=-2147024809
  Message=Eén of meerdere kolommen niet gevonden in 021214-0.txt
  Source=Selection Monitoring Tool
  StackTrace:
       at Selection_Monitoring_Tool.ViewModels.SettingsViewModel._importWorker_DoWork(Object sender, DoWorkEventArgs e) in c:\Users\Joost\Desktop\Selection Monitoring Tool\Selection Monitoring Tool\ViewModels\SettingsViewModel.cs:line 216
       at System.ComponentModel.BackgroundWorker.OnDoWork(DoWorkEventArgs e)
       at System.ComponentModel.BackgroundWorker.WorkerThreadStart(Object argument)
  InnerException:

正如@HansPassant 所建议的,我不得不取消选中 "Break when this exception type is user unhandeled" 复选框。