父类中的静态事件处理程序不是从Process触发的.在嵌套类中退出

每次调用CurlFile（）时，都会从ProcessObject类创建一个新对象。ProcessObject对象启动新进程。我希望每个对象中的Process.Exit事件触发父类中的静态事件处理程序，但由于某种原因，它似乎不起作用。

class Curl
{
    StringContainer oStrings = new StringContainer();
    private static int _counter = 0;
    private string _curl;
    public Curl()
    {
        //oStartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
        _curl = oStrings.Curl;
    }
    public void CurlFile(string _arg)
    {
        ProcessObject oProcessObject = new ProcessObject(_arg, _curl);
    }
    private static void oProcess_Exited(object sender, EventArgs e)
    {
        _counter++;
        if (_counter == 1000)
        {
            MessageBox.Show("here");
        }
    }
    private class ProcessObject
    {
        ProcessStartInfo oStartInfo = new ProcessStartInfo();
        Process oProcess = new Process();
        public ProcessObject(string _arg, string _curl)
        {
            oStartInfo.FileName = _curl;
            oStartInfo.Arguments = _arg;
            oProcess.EnableRaisingEvents = true;
            oProcess.Exited += new EventHandler(oProcess_Exited);
            oProcess = Process.Start(oStartInfo);
        }
    }
}

class Curl
{
    internal static List<ProcessObject> _processes = new List<ProcessObject>();
    // ....
    private static void oProcess_Exited(object sender, EventArgs e)
    {
        var p = sender as Process;
        if (p != null && _processes.Contains(p))
           _processes.Remove(p);
        _counter++;
        if (_counter == 1000)
        {
            MessageBox.Show("here");
        }
    }
    public ProcessObject(string _arg, string _curl)
    {
        oStartInfo.FileName = _curl;
        oStartInfo.Arguments = _arg;
        oStartInfo.UseShellExecute = false;
        oProcess.EnableRaisingEvents = true;
        oProcess.Exited += new EventHandler(oProcess_Exited);
        oProcess = Process.Start(oStartInfo);
        Curl._processes.Add(oProcess);
    }
}