ListView.SelectedIndexChanged Evento
Definição
Importante
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Ocorre quando o botão de seleção de um item é clicado, após o controle ListView manipular a operação de seleção.
public:
event EventHandler ^ SelectedIndexChanged;public event EventHandler SelectedIndexChanged;member this.SelectedIndexChanged : EventHandler Public Custom Event SelectedIndexChanged As EventHandler Tipo de evento
Exemplos
O exemplo a seguir mostra como criar um manipulador de eventos para o SelectedIndexChanged evento.
<%@ 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>
Comentários
O SelectedIndexChanged evento é gerado quando o botão Selecionar de um item é clicado, depois que o ListView controle manipula a operação de seleção. (Um botão Selecionar é um controle de botão cuja CommandName propriedade está definida como "Select".) Isso permite que você execute uma rotina personalizada sempre que esse evento ocorrer, como atualizar um rótulo de status com informações sobre o item selecionado no momento.
Para obter mais informações sobre como lidar com eventos, consulte Manipulando e levantando eventos.
Aplica-se a
Confira também
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