<a href="Default2.aspx?id=123&type=11ad">打开第二个页面id=123</a><br>

<a href="Default2.aspx?id=12&type=11ad">打开第二个页面id=12</a>

<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label><asp:Button ID="Button1" runat="server" Text="Button" OnClick="Button1_Click" />

protected void Page_Load(object sender, EventArgs e)

    {

        string type = Request.QueryString["type"].ToString();

        if (!IsPostBack)

        {

            if (Cache["'" + type + "'"] == null)

            {

                msg();

            }

            else

            {

                if (Cache["'" + type + "'"].ToString() == Request.QueryString["id"].ToString())

                {

                    Label1.Text = "我可以进入这个页面";

                }

                else

                {

                    Label1.Text = "有人已经进入该页面，请稍后。。。";

                    Button1.Visible = false;

                }

            }

        }

    }

    private void msg()

    {

        string type = Request.QueryString["type"];

        //Cache["'" + type + "'"] = Request.QueryString["id"].ToString();

        Cache.Insert("'"+type+"'", Request.QueryString["id"].ToString(), null, DateTime.Now.AddSeconds(), TimeSpan.Zero);

        Label1.Text = "我可以进入这个页面";

    }

    protected void Button1_Click(object sender, EventArgs e)

    {

        string type = Request.QueryString["type"];

        Cache.Remove("'" + type + "'");

        Response.Redirect("Default.aspx");

    }