数据表值不可访问

我有一个数据表，其中的项由后端填充。调试时，datatable不为null，datarow也不为null。但是没有找到特定项目。例如。但是ItemCode和ItemName为空：（

if (dtCurrentTable.Rows.Count > 0)
{
    for (int i = 1; i <= dtCurrentTable.Rows.Count; i++)
    {
        log.Debug("inside the for loop fnRecordExist");
        TextBox Itemcode = (TextBox)Grid_GRNEntry.Rows[rowIndex].Cells[0].FindControl("Item_Code");
        TextBox ItemName = (TextBox)Grid_GRNEntry.Rows[rowIndex].Cells[2].FindControl("Item_Name");
        drCurrentRow = dtCurrentTable.NewRow();
        if (drCurrentRow != null)
        {
            Itemcode.Text = dtCurrentTable.Rows[i - 1]["ItemCode"].ToString();
            ItemName.Text = dtCurrentTable.Rows[i - 1]["Item_Name"].ToString();
            rowIndex++;
        }
    }
    ViewState["CurrentTable"] = dtCurrentTable;
}