مشکل Server.MapPath کلاس

[Himalaya]

توی کلاس

using System.Web.UI.WebControls;

using System.Web.UI;

public class Class1

{

private FileUpload fileup = new FileUpload();

public Class1(FileUpload file)

{

this.fileup = file;

}

public void Upload(Page page)

{

fileup.SaveAs(page.Server.MapPath("~/photo/" + fileup.FileName));

page.Response.Write("<script>alert('Ok')</script>");

}

}

اینم کد دکمه واسه آپلود تو صفحه Default

protected void Button1_Click(object sender, EventArgs e)

{

Class1 a = new Class1(FileUpload1);

a.Upload(this.Page);

}