I have a simple question about filters. I have 4 dropdown lists which filter the data in my web application from MySQL database table. The first dropdown list is already sel
check out following links for populating cascading drop down list.
http://www.asp.net/ajaxLibrary/AjaxControlToolkitSampleSite/CascadingDropDown/CascadingDropDown.aspx
http://www.codeproject.com/KB/aspnet/CascadingDropDown.aspx
http://www.aspsnippets.com/Articles/Creating-Cascading-DropDownLists-in-ASP.Net.aspx
Code:
<table>
<tr>
<td>First</td>
<td><asp:DropDownList ID="DDLFirst" runat="server" AutoPostBack="true"
onselectedindexchanged="DDLFirst_SelectedIndexChanged"></asp:DropDownList></td>
</tr>
<tr>
<td>Secord</td>
<td><asp:DropDownList ID="DDLSecond" runat="server" AutoPostBack="true"
onselectedindexchanged="DDLSecond_SelectedIndexChanged">
<asp:ListItem Text="Select" Value="Select"></asp:ListItem>
</asp:DropDownList></td>
</tr>
<tr>
<td>Thrid</td>
<td><asp:DropDownList ID="DDLThird" runat="server"><asp:ListItem Text="Select" Value="Select"></asp:ListItem> </asp:DropDownList></td>
</tr>
</table>
// Code behind protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) { // your code to bind the first drop downlist
}
}
protected void DDLFirst_SelectedIndexChanged(object sender, EventArgs e)
{
if (DDLFirst.SelectedIndex > 0)
{
string FirstDDLValue = DDLFirst.SelectedItem.Value;
// below your code to get the second drop down list value filtered on first selection
}
}
protected void DDLSecond_SelectedIndexChanged(object sender, EventArgs e)
{
if (DDLSecond.SelectedIndex > 0)
{
string SecondDDLValue = DDLSecond.SelectedItem.Value;
// below your code to get the third drop down list value filtered on Second selection
}
}
Filter the second dropdown datasource with selectedvalue of first dropdown control
see this article http://www.asp.net/data-access/tutorials/master-detail-filtering-with-two-dropdownlists-