ListView.SelectedIndexChanged Event
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Occurs when an item's Select button is clicked, after the ListView control handles the select operation.
public:
event EventHandler ^ SelectedIndexChanged;public event EventHandler SelectedIndexChanged;member this.SelectedIndexChanged : EventHandler Public Custom Event SelectedIndexChanged As EventHandler Event Type
Examples
The following example shows how create an event handler for the SelectedIndexChanged event.
<%@ Page language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
//<Snippet3>
void ContactsListView_SelectedIndexChanged(Object sender, EventArgs e)
{
if (ContactsListView.SelectedIndex >= 0)
ViewState["SelectedKey"] = ContactsListView.SelectedValue;
else
ViewState["SelectedKey"] = null;
}
void ContactsListView_DataBound(Object sender, EventArgs e)
{
for (int i = 0; i < ContactsListView.Items.Count; i++)
{
// Ignore values that cannot be cast as integer.
try
{
if ((int)ContactsListView.DataKeys[i].Value == (int)ViewState["SelectedKey"])
ContactsListView.SelectedIndex = i;
}
catch { }
}
}
//</Snippet3>
void ContactsListView_PagePropertiesChanged(Object sender, EventArgs e)
{
ContactsListView.SelectedIndex = -1;
}
void ContactsListView_Sorting(Object sender, ListViewSortEventArgs e)
{
ContactsListView.SelectedIndex = -1;
}
void ClearButton_Click(Object sender, EventArgs e)
{
ViewState["SelectedKey"] = null;
ContactsListView.SelectedIndex = -1;
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>ListView SelectedIndex Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>ListView SelectedIndex Example</h3>
<asp:ListView ID="ContactsListView"
DataSourceID="ContactsDataSource"
DataKeyNames="ContactID"
OnDataBound="ContactsListView_DataBound"
OnSelectedIndexChanged="ContactsListView_SelectedIndexChanged"
OnPagePropertiesChanged="ContactsListView_PagePropertiesChanged"
OnSorting="ContactsListView_Sorting"
runat="server">
<LayoutTemplate>
<asp:Button runat="server" ID="SortButton"
CommandArgument="LastName" CommandName="Sort" Text="Sort" />
<asp:Button runat="server" ID="ClearButton"
OnClick="ClearButton_Click" Text="Clear Selection" /><br />
<table cellpadding="2" border="1" runat="server" id="tblContacts" width="640px">
<tr runat="server" id="itemPlaceholder" />
</table>
<asp:DataPager runat="server" ID="PeopleDataPager" PageSize="20">
<Fields>
<asp:NextPreviousPagerField
ShowFirstPageButton="true" ShowLastPageButton="true"
FirstPageText="|<< " LastPageText=" >>|"
NextPageText=" > " PreviousPageText=" < " />
</Fields>
</asp:DataPager>
</LayoutTemplate>
<ItemTemplate>
<tr runat="server">
<td valign="top">
<asp:Label ID="FirstNameLabel" runat="server" Text='<%#Eval("FirstName") %>' />
<asp:Label ID="LastNameLabel" runat="server" Text='<%#Eval("LastName") %>' />
</td>
<td>
<asp:Label ID="EmailLabel" runat="server" Text='<%#Eval("EmailAddress") %>' />
</td>
<td>
<asp:LinkButton ID="SelectButton" runat="server" CommandName="Select" Text="Select" />
</td>
</tr>
</ItemTemplate>
<SelectedItemTemplate>
<tr runat="server" style="background-color:#B0C4DE">
<td valign="top">
<asp:Label ID="FirstNameLabel" runat="server" Text='<%#Eval("FirstName") %>' />
<asp:Label ID="LastNameLabel" runat="server" Text='<%#Eval("LastName") %>' />
</td>
<td>
<asp:Label ID="EmailLabel" runat="server" Text='<%#Eval("EmailAddress") %>' />
</td>
<td> </td>
</tr>
</SelectedItemTemplate>
</asp:ListView>
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the AdventureWorks sample database. Use an ASP.NET -->
<!-- expression to retrieve the connection string value -->
<!-- from the Web.config file. -->
<asp:SqlDataSource ID="ContactsDataSource" runat="server"
ConnectionString="<%$ ConnectionStrings:AdventureWorks_DataConnectionString %>"
SelectCommand="SELECT [ContactID], [FirstName], [LastName], [EmailAddress]
FROM Person.Contact">
</asp:SqlDataSource>
</form>
</body>
</html>
<%@ Page language="VB" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
'<Snippet3>
Sub ContactsListView_SelectedIndexChanged(ByVal sender As Object, ByVal e As EventArgs)
If ContactsListView.SelectedIndex >= 0 Then
ViewState("SelectedKey") = ContactsListView.SelectedValue
Else
ViewState("SelectedKey") = Nothing
End If
End Sub
Sub ContactsListView_DataBound(ByVal sender As Object, ByVal e As EventArgs)
For i As Integer = 0 To ContactsListView.Items.Count - 1
' Ignore values that cannot be cast as integer.
Try
If Convert.ToInt32(ContactsListView.DataKeys(i).Value) = Convert.ToInt32(ViewState("SelectedKey")) Then _
ContactsListView.SelectedIndex = i
Catch
End Try
Next
End Sub
'</Snippet3>
Sub ContactsListView_PagePropertiesChanged(ByVal sender As Object, ByVal e As EventArgs)
ContactsListView.SelectedIndex = -1
End Sub
Sub ContactsListView_Sorting(ByVal sender As Object, ByVal e As ListViewSortEventArgs)
ContactsListView.SelectedIndex = -1
End Sub
Sub ClearButton_Click(ByVal sender As Object, ByVal e As EventArgs)
ViewState("SelectedKey") = Nothing
ContactsListView.SelectedIndex = -1
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>ListView SelectedIndex Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>ListView SelectedIndex Example</h3>
<asp:ListView ID="ContactsListView"
DataSourceID="ContactsDataSource"
DataKeyNames="ContactID"
OnDataBound="ContactsListView_DataBound"
OnSelectedIndexChanged="ContactsListView_SelectedIndexChanged"
OnPagePropertiesChanged="ContactsListView_PagePropertiesChanged"
OnSorting="ContactsListView_Sorting"
runat="server">
<LayoutTemplate>
<asp:Button runat="server" ID="SortButton"
CommandArgument="LastName" CommandName="Sort" Text="Sort" />
<asp:Button runat="server" ID="ClearButton"
OnClick="ClearButton_Click" Text="Clear Selection" /><br />
<table cellpadding="2" border="1" runat="server" id="tblContacts" width="640px">
<tr runat="server" id="itemPlaceholder" />
</table>
<asp:DataPager runat="server" ID="PeopleDataPager" PageSize="20">
<Fields>
<asp:NextPreviousPagerField
ShowFirstPageButton="true" ShowLastPageButton="true"
FirstPageText="|<< " LastPageText=" >>|"
NextPageText=" > " PreviousPageText=" < " />
</Fields>
</asp:DataPager>
</LayoutTemplate>
<ItemTemplate>
<tr runat="server">
<td valign="top">
<asp:Label ID="FirstNameLabel" runat="server" Text='<%#Eval("FirstName") %>' />
<asp:Label ID="LastNameLabel" runat="server" Text='<%#Eval("LastName") %>' />
</td>
<td>
<asp:Label ID="EmailLabel" runat="server" Text='<%#Eval("EmailAddress") %>' />
</td>
<td>
<asp:LinkButton ID="SelectButton" runat="server" CommandName="Select" Text="Select" />
</td>
</tr>
</ItemTemplate>
<SelectedItemTemplate>
<tr runat="server" style="background-color:#B0C4DE">
<td valign="top">
<asp:Label ID="FirstNameLabel" runat="server" Text='<%#Eval("FirstName") %>' />
<asp:Label ID="LastNameLabel" runat="server" Text='<%#Eval("LastName") %>' />
</td>
<td>
<asp:Label ID="EmailLabel" runat="server" Text='<%#Eval("EmailAddress") %>' />
</td>
<td> </td>
</tr>
</SelectedItemTemplate>
</asp:ListView>
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the AdventureWorks sample database. Use an ASP.NET -->
<!-- expression to retrieve the connection string value -->
<!-- from the Web.config file. -->
<asp:SqlDataSource ID="ContactsDataSource" runat="server"
ConnectionString="<%$ ConnectionStrings:AdventureWorks_DataConnectionString %>"
SelectCommand="SELECT [ContactID], [FirstName], [LastName], [EmailAddress]
FROM Person.Contact">
</asp:SqlDataSource>
</form>
</body>
</html>
Remarks
The SelectedIndexChanged event is raised when an item's Select button is clicked, after the ListView control handles the select operation. (A Select button is a button control whose CommandName property is set to "Select".) This enables you to perform a custom routine whenever this event occurs, such as updating a status label with information about the currently selected item.
For more information about how to handle events, see Handling and Raising Events.
