Question

我如何捕捉Exception抛出的DataReceivedEventHandler？

此帖子与我的相同，但适用于异步方法而非处理程序：Catch an exception thrown by an async void method

这是我的代码的过度简化版本：

public static void Main()
{
    try
    {
        using (Process process = CreateProcess())
        {
            process.Start();
            process.BeginErrorReadLine();

            process.WaitForExit();
        }   
    }
    catch (Exception e)
    {
        Console.WriteLine(e.Message); // never goes here
    }
}

private static Process CreateProcess()
{
    Process process = new Process();

    process.ErrorDataReceived += ActionOnErrorDataReceived;

    return process;
}

private static void ActionOnErrorDataReceived(object sender, DataReceivedEventArgs e)
{
    throw new Exception(e?.Data);
}

Answer 1

由于Dortimer的comment使我理解了，所以从事件处理程序中引发异常是一种不好的做法。因此，这是实现我正在尝试实现的等效方法：

bool error = false;
string errorMsg = String.Empty;

public static void Main()
{
    try
    {
        using (Process process = CreateProcess())
        {
            process.Start();
            process.BeginErrorReadLine();

            process.WaitForExit();

            if (error)
            {
                throw new Exception(errorMsg);
            }
        }   
    }
    catch (Exception e)
    {
        Console.WriteLine(e.Message);
    }
}

private static Process CreateProcess()
{
    Process process = new Process();

    process.ErrorDataReceived += ActionOnErrorDataReceived;

    return process;
}

private static void ActionOnErrorDataReceived(object sender, DataReceivedEventArgs e)
{
    error = true;
    errorMsg = e?.Data;

    Process p = (sender as Process);
    if (p != null && p.HasExited == false)
    {
        p.Kill();
    }
}

如何捕获由DataReceivedEventHandler引发的异常？

1 个答案: