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我知道它会BackgroundWorker吃未经处理的异常并将它们传递给RunWorkerCompleted e.Error属性，并且处理异常的正确方法是检查e.Error != null.

在DoWork事件的方法中，我有几个try catch块，但只有其中一些块在工作。如果FailedOperationException我的代码试图访问不可用的 dll 中的类，则会FileNotFoundException抛出一个不会被邻居FileNotFoundException或Exception捕获块捕获的类。取而代之的是，它e.Error属于RunWorkerCompleted.

为什么只捕获了一些异常？

代码：

    try
    {
        SqlConnection connection = new SqlConnection(Properties.Settings.Default.CharityConnectionString);
        String dataSource = connection.DataSource;

        if (((ActionType)e.Argument) == ActionType.Backup)
        {
            try
            {
                lblWait.Text = "Starting backup operation ...";
                ServerConnection serverConnection = new ServerConnection(dataSource);
                Server sqlServer = new Server(serverConnection); // The exception is thrown here
                String originalBackupPath = fileName;
                BackupDeviceItem backupDevice = new BackupDeviceItem(originalBackupPath, DeviceType.File);
                Backup backup = new Backup();
                backup.Action = BackupActionType.Database;
                backup.Database = "Charity";
                backup.Devices.Add(backupDevice);
                backup.Initialize = true;
                backup.Checksum = true;
                backup.ContinueAfterError = true;
                backup.Incremental = false;
                backup.LogTruncation = BackupTruncateLogType.Truncate;
                backup.SqlBackup(sqlServer);
                MessageBox.Show("Backup was successfull", "", MessageBoxButtons.OK, MessageBoxIcon.Information);
            }
            catch (FileNotFoundException ex) // this catch doesn't work for FileNotFoundException exceptions
            {
                MessageBox.Show("Error in operation" + ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
            catch (FailedOperationException)
            {
                MessageBox.Show("Access to the selected folder is denied", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
            catch (Exception) // and this catch doesn't work for FileNotFoundException, too
            {
                MessageBox.Show("Error in operation", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }
    }
    catch(Exception)
    {
        MessageBox.Show("Error in operation", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
    }

FileNotFoundException带有消息“无法加载文件或程序集。Microsoft.SqlServer.ConnectionInfo ”仅显示在e.Error. 我知道如何通过私人安装程序集来解决此异常。

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1 回答 1

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我的猜测是你有错误的例外。你在看InnerExceptionine.Error吗？

此代码按预期工作：

using System;
using System.ComponentModel;
using System.IO;
using System.Threading;

class Program
{
    static void Main(string[] args)
    {
        BackgroundWorker worker = new BackgroundWorker();
        worker.DoWork += (s, e) =>
        {
            try
            {
                throw new FileNotFoundException();
            }
            catch (FileNotFoundException)
            {
                Console.WriteLine("FileNotFoundException caught");
            }
        };

        worker.RunWorkerCompleted += (s, e) =>
        {
            if (e.Error != null)
                Console.WriteLine("RunWorkerCompleted error is {0}", e);
        };

        worker.RunWorkerAsync();
        while (worker.IsBusy)
            Thread.Sleep(1);
    }
}
于 2012-10-31T16:55:26.397 回答