Code for Reading XML File

first create xml file & add using System.Xml  NAMESPACE
then create button & grid .On button click its read xml file.
 STEP1.
CREATE XML FILE
<?xml version="1.0" encoding="utf-8" ?>
<ProductList>
  <Products>
    <ProductId>1</ProductId>
    <ProductName>Rice</ProductName>
    <Rate>27</Rate>
  </Products>
  <Products>
    <ProductId>2</ProductId>
    <ProductName>Wheat</ProductName>
    <Rate>20</Rate>
  </Products>
</ProductList>



STEP2

<asp:GridView ID="GridView1" runat="server">
        </asp:GridView>
        <asp:Button ID="Button1" runat="server" Text="Button" onclick="Button1_Click" />


STEP3
 protected void Button1_Click(object sender, EventArgs e)
    {
        DataSet ds = new DataSet();
        ds.ReadXml(Server.MapPath("XMLFile.xml"));
        GridView1.DataSource = ds;
        GridView1.DataBind();

    }
Next Recommended Reading Bind DropDownList using XML File.