显示图片,该如何解决

显示图片
protected void Button1_Click(object sender, EventArgs e)
  {
  if (this.FileUpload1.HasFile)
  {
  string path, filepath;
  path = Server.MapPath(".");
  filepath = path + this.FileUpload1.FileName;
  this.FileUpload1.SaveAs(filepath);
  this.Image1.Visible = true;
  this.Image1.ImageUrl = "." + this.FileUpload1.FileName;
   
  }
  else
  {
  Label1.Text = "this is null!";
  }

各位帮我改一下，为什么执行的时候图片可以上传却没有显示？

------解决方案--------------------------------------------------------
this.Image1.ImageUrl =filepath