GridViewSortEventHandler Delegar
Definição
Importante
Algumas informações se referem a produtos de pré-lançamento que podem ser substancialmente modificados antes do lançamento. A Microsoft não oferece garantias, expressas ou implícitas, das informações aqui fornecidas.
public delegate void GridViewSortEventHandler(System::Object ^ sender, GridViewSortEventArgs ^ e);public delegate void GridViewSortEventHandler(object sender, GridViewSortEventArgs e);type GridViewSortEventHandler = delegate of obj * GridViewSortEventArgs -> unitPublic Delegate Sub GridViewSortEventHandler(sender As Object, e As GridViewSortEventArgs)Parâmetros
- sender
- Object
A fonte do evento.
Um objeto de GridViewSortEventArgs que contém os dados do evento.
Exemplos
O exemplo a seguir demonstra como adicionar programaticamente um GridViewSortEventHandler delegado ao Sorting evento de um GridView controle.
<%@ 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">
void Page_Load(Object sender, EventArgs e)
{
// Create a new GridView object.
GridView authorGridView = new GridView();
// Set the GridView object's properties.
authorGridView.ID = "AuthorGridView";
authorGridView.DataSourceID = "AuthorsSqlDataSource";
authorGridView.AutoGenerateColumns = true;
authorGridView.AllowSorting = true;
// Programmatically register the event-handling methods.
authorGridView.Sorting += new GridViewSortEventHandler(this.AuthorsGridView_Sorting);
// Add the GridView object to the Controls collection
// of the PlaceHolder control.
GridViewPlaceHolder.Controls.Add(authorGridView);
}
void AuthorsGridView_Sorting(Object sender, GridViewSortEventArgs e)
{
// Cancel the sorting operation if the user attempts to sort
// the Contract column.
if(e.SortExpression == "contract")
{
e.Cancel = true;
Message.Text = "You cannot sort the Contract column.";
}
else
{
// Clear the message label.
Message.Text = "";
}
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>GridViewSortEventHandler Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>GridViewSortEventHandler Example</h3>
<asp:label id="Message"
forecolor="Red"
runat="server"/>
<br/>
<asp:placeholder id="GridViewPlaceHolder"
runat="Server"/>
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the Pubs sample database. -->
<asp:sqldatasource id="AuthorsSqlDataSource"
selectcommand="SELECT [au_id], [au_lname], [au_fname], [address], [city], [state], [zip], [contract] FROM [authors]"
updatecommand="UPDATE authors SET au_lname=@au_lname, au_fname=@au_fname, address=@address, city=@city, state=@state, zip=@zip, contract=@contract WHERE (authors.au_id = @au_id)"
connectionstring="server=localhost;database=pubs;integrated security=SSPI"
runat="server">
</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">
Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
' Create a new GridView object.
Dim authorGridView As GridView = New GridView
' Set the GridView object's properties.
authorGridView.ID = "AuthorGridView"
authorGridView.DataSourceID = "AuthorsSqlDataSource"
authorGridView.AutoGenerateColumns = True
authorGridView.AllowSorting = True
' Programmatically register the event-handling methods.
AddHandler authorGridView.Sorting, AddressOf AuthorsGridView_Sorting
' Add the GridView object to the Controls collection
' of the PlaceHolder control.
GridViewPlaceHolder.Controls.Add(authorGridView)
End Sub
Sub AuthorsGridView_Sorting(ByVal sender As Object, ByVal e As GridViewSortEventArgs)
' Cancel the sorting operation if the user attempts to sort
' the Contract column.
If e.SortExpression = "contract" Then
e.Cancel = True
Message.Text = "You cannot sort the Contract column."
Else
' Clear the message label.
Message.Text = ""
End If
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>GridViewSortEventHandler Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>GridViewSortEventHandler Example</h3>
<asp:label id="Message"
forecolor="Red"
runat="server"/>
<br/>
<asp:placeholder id="GridViewPlaceHolder"
runat="Server"/>
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the Pubs sample database. -->
<asp:sqldatasource id="AuthorsSqlDataSource"
selectcommand="SELECT [au_id], [au_lname], [au_fname], [address], [city], [state], [zip], [contract] FROM [authors]"
updatecommand="UPDATE authors SET au_lname=@au_lname, au_fname=@au_fname, address=@address, city=@city, state=@state, zip=@zip, contract=@contract WHERE (authors.au_id = @au_id)"
connectionstring="server=localhost;database=pubs;integrated security=SSPI"
runat="server">
</asp:sqldatasource>
</form>
</body>
</html>
O exemplo a seguir demonstra como adicionar declarativamente um GridViewSortEventHandler delegado ao Sorting evento de um GridView controle.
<%@ 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">
void CustomersGridView_Sorting(Object sender, GridViewSortEventArgs e)
{
// Cancel the sorting operation if the user attempts
// to sort by address.
if (e.SortExpression == "Address")
{
e.Cancel = true;
Message.Text = "You cannot sort by address.";
SortInformationLabel.Text = "";
}
else
{
Message.Text = "";
}
}
void CustomersGridView_Sorted(Object sender, EventArgs e)
{
// Display the sort expression and sort direction.
SortInformationLabel.Text = "Sorting by " +
CustomersGridView.SortExpression.ToString() +
" in " + CustomersGridView.SortDirection.ToString() +
" order.";
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>GridView Sorting Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>GridView Sorting Example</h3>
<asp:label id="Message"
forecolor="Red"
runat="server"/>
<br/>
<asp:label id="SortInformationLabel"
forecolor="Navy"
runat="server"/>
<br/>
<asp:gridview id="CustomersGridView"
datasourceid="CustomersSource"
autogeneratecolumns="true"
allowpaging="true"
emptydatatext="No data available."
allowsorting="true"
onsorting="CustomersGridView_Sorting"
onsorted="CustomersGridView_Sorted"
runat="server">
</asp:gridview>
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the Northwind sample database. Use an ASP.NET -->
<!-- expression to retrieve the connection string value -->
<!-- from the Web.config file. -->
<asp:sqldatasource id="CustomersSource"
selectcommand="Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]"
connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>"
runat="server"/>
</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">
Sub CustomersGridView_Sorting(sender As Object, e As GridViewSortEventArgs)
' Cancel the sorting operation if the user attempts
' to sort by address.
If e.SortExpression = "Address" Then
e.Cancel = True
Message.Text = "You cannot sort by address."
SortInformationLabel.Text = ""
Else
Message.Text = ""
End If
End Sub
Sub CustomersGridView_Sorted(ByVal sender As Object, ByVal e As EventArgs)
' Display the sort expression and sort direction.
SortInformationLabel.Text = "Sorting by " & _
CustomersGridView.SortExpression.ToString() & _
" in " & CustomersGridView.SortDirection.ToString() & _
" order."
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>GridView Sorted and Sorting Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>GridView Sorted and Sorting Example</h3>
<asp:label id="Message"
forecolor="Red"
runat="server"/>
<br/>
<asp:label id="SortInformationLabel"
forecolor="Navy"
runat="server"/>
<br/>
<asp:gridview id="CustomersGridView"
datasourceid="CustomersSource"
autogeneratecolumns="true"
allowpaging="true"
emptydatatext="No data available."
allowsorting="true"
onsorting="CustomersGridView_Sorting"
onsorted="CustomersGridView_Sorted"
runat="server">
</asp:gridview>
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the Northwind sample database. Use an ASP.NET -->
<!-- expression to retrieve the connection string value -->
<!-- from the Web.config file. -->
<asp:sqldatasource id="CustomersSource"
selectcommand="Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]"
connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>"
runat="server"/>
</form>
</body>
</html>
Comentários
O Sorting evento é gerado quando o hiperlink para classificar uma coluna é clicado, mas antes que o GridView controle manipule a operação de classificação. Isso permite que você forneça um método de manipulação de eventos que executa uma rotina personalizada, como cancelar a operação de classificação, sempre que esse evento ocorrer.
Ao criar um GridViewSortEventHandler delegado, você identifica o método que manipulará o evento. Para associar o evento ao manipulador de eventos, adicione uma instância do delegado ao evento. O manipulador de eventos é chamado sempre que o evento ocorre, a menos que você remova o representante. Para obter mais informações sobre delegados do manipulador de eventos, consulte Manipulando e levantando eventos.
Métodos de Extensão
| GetMethodInfo(Delegate) |
Obtém um objeto que representa o método representado pelo delegado especificado. |
Aplica-se a
Confira também
Colabore connosco no GitHub
A origem deste conteúdo pode ser encontrada no GitHub, onde também pode criar e rever problemas e pedidos Pull. Para mais informações, consulte o nosso guia do contribuidor.
