รบกวนผู้รู้แนะนำทีครับ ผม convert excel ได้แต่ข้อมูลเข้าไม่ครบ ไม่ทราบสาเหตุช่วยแนะนำทีครับ

protected void Button1_Click(object sender, EventArgs e)
    {
        //***ส่วนของการอัพโหลดไฟล์ Excel***//
        if (FileUpload1.HasFile)
        {
            string FileName = Path.GetFileName(FileUpload1.PostedFile.FileName);
            string Extension = Path.GetExtension(FileUpload1.PostedFile.FileName);
            string FolderPath = ConfigurationManager.AppSettings["FolderPath"];

            string FilePath = Server.MapPath(FolderPath + FileName);
            FileUpload1.SaveAs(FilePath);
            Import_To_Grid(FilePath, Extension, RadioButtonList1.SelectedItem.Text);
        }
        SqlTransaction tr = objConn.BeginTransaction();
        SqlCommand cmd = objConn.CreateCommand();
    }
    private void Import_To_Grid(string FilePath, string Extension, string isHDR)
    {
        string conStr = "";
        switch (Extension)
        {
            case ".xls": //Excel 97-03
                conStr = ConfigurationManager.ConnectionStrings["Excel03ConString"].ConnectionString;
                break;
            case ".xlsx": //Excel 07
                conStr = ConfigurationManager.ConnectionStrings["Excel07ConString"].ConnectionString;
                break;
        }
        conStr = String.Format(conStr, FilePath, isHDR);
        OleDbConnection connExcel = new OleDbConnection(conStr);
        OleDbCommand cmdExcel = new OleDbCommand();
        OleDbDataAdapter oda = new OleDbDataAdapter();
        DataTable dt = new DataTable();
        cmdExcel.Connection = connExcel;

        //Get the name of First Sheet
        connExcel.Open();
        DataTable dtExcelSchema;
        dtExcelSchema = connExcel.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);
        string SheetName = dtExcelSchema.Rows[0]["TABLE_NAME"].ToString();
        connExcel.Close();

        //Read Data from First Sheet
        connExcel.Open();
        cmdExcel.CommandText = "SELECT * From [" + SheetName + "]";
        oda.SelectCommand = cmdExcel;
        oda.Fill(dt);
        connExcel.Close();

        //Bind Data to GridView #1
        GridView1.Caption = Path.GetFileName(FilePath);
        GridView1.DataSource = dt;
        GridView1.DataBind();
    }
    protected void PageIndexChanging(object sender, GridViewPageEventArgs e)
    {
        string FolderPath = ConfigurationManager.AppSettings["FolderPath"];
        string FileName = GridView1.Caption;
        string Extension = Path.GetExtension(FileName);
        string FilePath = Server.MapPath(FolderPath + FileName);

        Import_To_Grid(FilePath, Extension, RadioButtonList1.SelectedItem.Text);
        GridView1.PageIndex = e.NewPageIndex;
        GridView1.DataBind();
    }