如何在不隐藏类基变量的情况下更改访问修饰符？ [复制]

Question

我正在尝试稍微扩展 Process 类，以添加 Process.Exited 委托的访问控制并将它们限制为一个。到目前为止，我有这个结果：

public class ProcessWithData : Process
{
    public EventHandler CurrentEventHandler { get; private set; }
    public new bool EnableRaisingEvents = true;
    private new EventHandler Exited;
    public void SetHandler(EventHandler eventHandler)
    {
        if (CurrentEventHandler != null) Exited -= CurrentEventHandler;
        CurrentEventHandler = eventHandler;
        Exited += CurrentEventHandler;
    }
}

但是，行

private new EventHandler Exited;

覆盖作为基础的 Process 类的现有 EventHandler。因此

var proc = Process.Start("foo.exe");
ProcessWithData procwithdata = (ProcessWithData)proc;

应该在施放时销毁 Exited 事件处理程序。

如何在不重新定义（和销毁）Process 类中的现有实例的情况下为其设置private 修饰符？

Answer 1

我同意@madreflection 的观点，认为包装器或装饰器是可行的方法。也就是说，使用base 设置有问题的属性将起作用。

public class ProcessWithData : Process
{
    public ProcessWithData(string filename)
    {
        base.StartInfo.FileName = filename;
    }

    public EventHandler CurrentEventHandler { get; private set; }

    public void SetHandler(EventHandler eventHandler)
    {
        // set Exited via base object
        if (CurrentEventHandler != null) base.Exited -= CurrentEventHandler;
        CurrentEventHandler = eventHandler;
        base.Exited += CurrentEventHandler;
    }
}

...并像这样使用它，它有点冗长但它有效...

var proc = new ProcessWithData("foo.exe");
        proc.SetHandler(ProcOnExited);
        proc.EnableRaisingEvents = true;
        proc.Start();

private void ProcOnExited(object sender, EventArgs e)
{
    // do stuff
}