Fill DropdownList With XML File

This topic explain how to fill two dropdownlists with XML file on selectedidexchaned of other dropdownlist.Put City dropdownlist in UpdatePanel so that not the entire page get postback and add a AsyncPostBackTrigger.

<asp:UpdatePanel ID="updatePanel" runat="server" UpdateMode="Conditional">

<ContentTemplate>

<asp:DropDownList ID="ddlCity" runat="server">

/asp:DropDownList>

/ContentTemplate>

<Triggers>

<asp:AsyncPostBackTrigger ControlID="ddlState" />

/Triggers>

/asp:UpdatePanel>

XmlTextReader xRead = new XmlTextReader(Server.MapPath("StatesAndCity.xml"));

XmlDocument doc = new XmlDocument();

doc.Load(Server.MapPath("StatesAndCity.xml"));

XmlNodeList xStateList = doc.GetElementsByTagName("state");

for (int i = 0; i <>

{

ddlState.Items.Add(xStateList.Item(i).Attributes.Item(0).Value.ToString());

ddlState.Items[i].Text = xStateList.Item(i).Attributes.Item(0).Value.ToString();

ddlState.Items[i].Value = xStateList.Item(i).Attributes.Item(1).Value.ToString();

// ddlState.SelectedIndex = i;

}

protected void ddlState_SelectedIndexChanged(object sender, EventArgs e)

{

ddlCity.Items.Clear();

XmlTextReader xRead = new XmlTextReader(Server.MapPath("StatesAndCity.xml"));

XmlDocument doc = new XmlDocument();

doc.Load(Server.MapPath("StatesAndCity.xml"));

XmlNodeList xStateList = doc.GetElementsByTagName("state");

for (int j = 0; j <>

{

if (xStateList.Item(j).Attributes.GetNamedItem("name").Value == ddlState.SelectedItem.Text)

{

XmlNodeList xCityList = xStateList.Item(j).ChildNodes;// doc.GetElementsByTagName("state").Item(Convert.ToInt32(doc.GetElementsByTagName("state").Item(0).Value)).ChildNodes

for (int i = 0; i <>

{

ddlCity.Items.Add(xCityList.Item(i).Attributes.Item(0).Value.ToString());

}

}

}