虽然4.0有了新特性。

Named And Optional Arguments - 命名参数和可选参数

public partialclass NamedAndOptionalArguments : System.Web.UI.Page
    {
        protectedvoid Page_Load(object sender, EventArgs e)
        {
            Write("hello");
            Write("hello","webabcd");
            Write("hello", p3:false, p2:"webabcd");
        }

        privatevoid Write(string p1,string p2 = "p2",bool p3= true)
        {
            Response.Write(string.Format("p1:{0}; p2:{1}; p3:{2}", p1, p2, p3.ToString()));
            Response.Write("<br />");
        }
    }