//DataTable DateSet 都可以用来读取xml数据和写入xml数据
protected voidButton1_Click(object sender, EventArgs e)
{
  DataTabledt = new DataTable("Employee");
  DataColumndcID = new DataColumn("ID", typeof(string));
  DataColumndcName = new DataColumn("NAME", typeof(string));
  DataColumndcAGE = new DataColumn("AGE", typeof(string));
  DataColumndcDEPT = new DataColumn("DEPT", typeof(string));
  dt.Columns.AddRange(new DataColumn[] {dcID, dcName, dcAGE, dcDEPT });
  DataRowdr = dt.NewRow();
  dr["ID"]= "3";
  dr["NAME"]= "chen";
  dr["AGE"]= "21";
  dr["DEPT"]= "技术部";
  dt.Rows.Add(dr);
  DataSetds2 = new DataSet();
  ds2.Tables.Add(dt);
  DataSetds = new DataSet();
  ds.ReadXml(Server.MapPath("Employee.xml"));
  ds.Merge(ds2);//合并数据
  ds.WriteXml(Server.MapPath("Employee.xml"));
  Page.ClientScript.RegisterStartupScript(GetType(), "", "alert('写入成功')",true);
}
protected voidButton2_Click(object sender, EventArgs e)
{
  DataSetds = new DataSet();
  ds.ReadXml(Server.MapPath("Employee.xml"));
  GridView1.DataSource = ds;
  GridView1.DataBind();
}