System.ArgumentOutOfRangeException: StartIndex 不能小于 0。
protected void Page_Load(object sender, EventArgs e)
  {
  if (!IsPostBack)
  {
  string str = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath("../../App_Data/tuohaichuanmei.mdb") + ";Persist Security Info=False";
  OleDbConnection conn = new OleDbConnection(str);
  conn.Open();
  OleDbCommand cmd = new OleDbCommand("select * from News where ID="+Request["id"].ToString()+"",conn);
  OleDbDataReader rad = cmd.ExecuteReader();  
  if (rad.Read())
  {
  BiaoTi.Text = rad["Title"].ToString();
  NeiRong.Text = rad["Body"].ToString();
  HiddenField1.Value = rad["Img"].ToString();
  }
  rad.Close();
  conn.Close();
  }
  }
  protected void Button1_Click(object sender, EventArgs e)
  {
  string str = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath("../../App_Data/tuohaichuanmei.mdb") + ";Persist Security Info=False";
  OleDbConnection conn = new OleDbConnection(str);
  conn.Open();
  string Img = string.Empty;
  if (FileUpload1.HasFile == true)
  {
  string tif = Img.Substring(Img.LastIndexOf('.'));
  string NewName = DateTime.Now.ToString();
  string NewStr = NewName.Replace('-', '2').Replace(':', '2').Replace(' ', '2');
  FileUpload1.SaveAs(Server.MapPath("~/Admin/Img/" + NewStr + tif));
  File.Delete(Server.MapPath("~/Admin/Img/" + HiddenField1.Value));
  OleDbCommand cmd = new OleDbCommand("update News set Title='"+BiaoTi.Text+"',Body='"+NeiRong.Text+"',Img='"+NewStr+tif+"' where ID="+Request["id"].ToString()+"", conn);
  cmd.ExecuteNonQuery();
  }
  else
  {
  OleDbCommand cmd = new OleDbCommand("insert into News(Title,Body,Img)values('" + BiaoTi.Text + "','" + NeiRong.Text + "')", conn);
  cmd.ExecuteNonQuery();
  }
  conn.Close();
  }


请教高人指点 事成之后必有重谢

------解决方案--------------------

C# code

string Img = string.Empty;
  if (FileUpload1.HasFile == true)
  {
  string tif = Img.Substring(Img.LastIndexOf('.'));
｝

------解决方案--------------------

断点吧 看看下表里的值哪个小于0