未捕获C#用户定义的异常

时间:2016-11-18 10:10:30

标签: c# exception-handling

我定义了这样的自定义异常:

[Serializable]
    public class WrongFileException : Exception
    {
        public WrongFileException()
        {

        }
        public WrongFileException(string message) : base(message)
        {

        }

        public WrongFileException(string message, Exception innerExeException) : base(message, innerExeException)
        {

        }
    }

我有一个打开文件的按钮,我想在错误的文件时抛出异常:

private void PanelOpen_Click(object sender, RoutedEventArgs e)
    {
        Microsoft.Win32.OpenFileDialog opendlg = new Microsoft.Win32.OpenFileDialog();
        opendlg.DefaultExt = ".xml";
        opendlg.Filter="XML Files|*.xml";

        Nullable<bool> result = opendlg.ShowDialog();

        if (result == true)
        {
            XmlSerializer XMLSerial = new XmlSerializer(typeof(List<Panel>));
            FileStream fsCheck = new FileStream(opendlg.FileName, FileMode.Open);
            XmlReader reader = new XmlTextReader(fsCheck);
            fsCheck.Close();
            if (!XMLSerial.CanDeserialize(reader))
            {
                throw (new WrongFileException("Wrong data sructure for PanelList"));
            }
            try
            {
                using (FileStream fsRead = new FileStream(opendlg.FileName, FileMode.Open, FileAccess.Read))
                {
                    PanelList = XMLSerial.Deserialize(fsRead) as List<Panel>;
                }
                PanelBoxListView.ItemsSource = PanelList;
                PanelBoxListView.Items.Refresh();
            }
            catch(WrongFileException q)
            {
                MessageBox.Show("WrongFileException: {0}", q.Message);
                throw;
            }
        }
        CheckForListEntries();
    }

测试它试图打开一个无效的文件我得到“WrongFileException未处理”。我不明白为什么因为我正在捕捉异常?

2 个答案:

答案 0 :(得分:2)

只有在try块中抛出异常时才会捕获它。

            try
            {
                if (!XMLSerial.CanDeserialize(reader))
                {
                    throw (new WrongFileException("Wrong data sructure for PanelList"));
                 }
                using (FileStream fsRead = new FileStream(opendlg.FileName, FileMode.Open, FileAccess.Read))
                {
                    PanelList = XMLSerial.Deserialize(fsRead) as List<Panel>;
                }
                PanelBoxListView.ItemsSource = PanelList;
                PanelBoxListView.Items.Refresh();
            }
            catch(WrongFileException q)
            {
                MessageBox.Show("WrongFileException: {0}", q.Message);
                throw;
            }

答案 1 :(得分:1)

<{em> <{1}}阻止你的throw (new WrongFileException(...)); ,因此try - try永远不会变得相关。