如何在线程或计时器中访问HttpServerUtility.MapPath方法？

using System;
using System.Web.UI;

public partial class MyWebForm : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!Page.IsCrossThread)
        {
            string path = HttpServerUtility.MapPath("/myContent");
            textBox1.Text = path;
        }
        else
        {
            WebForm1.PerformCrossThreadCall(delegate()
            {
                string path = HttpServerUtility.MapPath("/myContent");
                textBox1.Text = path;
            });
        }
    }

    public void PerformCrossThreadCall(Action action)
    {
        if (!CrossThreadCallManager.IsBeginCalled)
        {
            object parameter = "";
            CrossThreadCallManager.BeginCall(parameter, BeginCallCallback, parameter);
        }
        action();
    }

    public void BeginCallCallback(IAsyncResult ar)
    {
        if (!CrossThreadCallManager.IsEndCalled)
        {
            string[] parameterArray = (string[])ar.AsyncState;
            action(parameterArray);
            CrossThreadCallManager.EndCall(ar);
        }
    }