gridview在没有数据时显示表头，可以使用如下方法：
public void BuildNoRecords(GridView gridView, DataSet ds)
{
if (ds.Tables[0].Rows.Count == 0)
{
ds.Tables[0].Rows.Add(ds.Tables[0].NewRow());
gridView.DataSource = ds;
gridView.DataBind();
int columnCount = gridView.Rows[0].Cells.Count;
gridView.Rows[0].Cells.Clear();
gridView.Rows[0].Cells.Add(new TableCell());
gridView.Rows[0].Cells[0].ColumnSpan = columnCount;
gridView.Rows[0].Cells[0].Text = "No Records Found.";
}
else
{
gridView.DataSource = ds;
gridView.DataBind();
}
}