ListView.ItemEditing Evento
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.
Ocorre quando uma operação de edição é solicitada, mas antes que o item ListView seja colocado no modo de edição.
public:
event EventHandler<System::Web::UI::WebControls::ListViewEditEventArgs ^> ^ ItemEditing;public event EventHandler<System.Web.UI.WebControls.ListViewEditEventArgs> ItemEditing;member this.ItemEditing : EventHandler<System.Web.UI.WebControls.ListViewEditEventArgs> Public Custom Event ItemEditing As EventHandler(Of ListViewEditEventArgs) Tipo de evento
Exemplos
O exemplo a seguir mostra como adicionar um manipulador de eventos para o ItemEditing evento.
Importante
Este exemplo tem uma caixa de texto que aceita a entrada do usuário, que é uma possível ameaça à segurança. Por padrão, ASP.NET páginas da Web validam que a entrada do usuário não inclui elementos html ou script. Para obter mais informações, consulte Visão geral de explorações de script.
<%@ 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()
{
Message.Text = String.Empty;
}
//<Snippet2>
void ProductsListView_ItemEditing(Object sender, ListViewEditEventArgs e)
{
ListViewItem item = ProductsListView.Items[e.NewEditIndex];
Label dateLabel = (Label)item.FindControl("DiscontinuedDateLabel");
if (String.IsNullOrEmpty(dateLabel.Text))
return;
//Verify if the item is discontinued.
DateTime discontinuedDate = DateTime.Parse(dateLabel.Text);
if (discontinuedDate < DateTime.Now)
{
Message.Text = "You cannot edit a discontinued item.";
e.Cancel = true;
ProductsListView.SelectedIndex = -1;
}
}
//</Snippet2>
void DiscontinuedDateCalendar_OnSelectionChanged(Object sender, EventArgs e)
{
TextBox dateTextBox =
(TextBox)ProductsListView.EditItem.FindControl("DiscontinuedDateTextBox");
Calendar calendarObject = (Calendar)sender;
dateTextBox.Text = calendarObject.SelectedDate.ToString("d");
}
DateTime GetDateTime(object dateValue)
{
if (dateValue == DBNull.Value)
return DateTime.Now;
else
return (DateTime)dateValue;
}
protected void ProductsListView_PagePropertiesChanging(object sender, PagePropertiesChangingEventArgs e)
{
// Clears the edit index selection when paging.
ProductsListView.EditIndex = -1;
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>ListView Edit Item Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>ListView Edit Item Example</h3>
<asp:Label ID="Message"
ForeColor="Red"
runat="server"/>
<br/>
<asp:ListView ID="ProductsListView"
DataSourceID="ProductsDataSource"
DataKeyNames="ProductID"
OnItemEditing="ProductsListView_ItemEditing"
ConvertEmptyStringToNull="true"
OnPagePropertiesChanging="ProductsListView_PagePropertiesChanging"
runat="server" >
<LayoutTemplate>
<table cellpadding="2" runat="server" id="tblProducts" width="640px">
<tr runat="server" id="itemPlaceholder" />
</table>
<asp:DataPager runat="server" ID="ProductsDataPager" PageSize="12">
<Fields>
<asp:NextPreviousPagerField
ShowFirstPageButton="true" ShowLastPageButton="true"
FirstPageText="|<< " LastPageText=" >>|"
NextPageText=" > " PreviousPageText=" < " />
</Fields>
</asp:DataPager>
</LayoutTemplate>
<ItemTemplate>
<tr runat="server">
<td valign="top">
<asp:LinkButton ID="EditButton" runat="server" Text="Edit" CommandName="Edit" />
</td>
<td valign="top">
<asp:Label ID="NameLabel" runat="server" Text='<%#Eval("Name") %>' />
</td>
<td valign="top">
<asp:Label ID="ProductNumberLabel" runat="server" Text='<%#Eval("ProductNumber") %>' />
</td>
<td>
<asp:Label ID="DiscontinuedDateLabel" runat="server"
Text='<%#Eval("DiscontinuedDate", "{0:d}") %>' />
</td>
</tr>
</ItemTemplate>
<EditItemTemplate>
<tr style="background-color:#ADD8E6">
<td valign="top">
<asp:LinkButton ID="UpdateButton" runat="server"
CommandName="Update" Text="Update" /><br />
<asp:LinkButton ID="CancelButton" runat="server"
CommandName="Cancel" Text="Cancel" />
</td>
<td valign="top" colspan="2">
<asp:Label runat="server" ID="NameLabel"
AssociatedControlID="NameTextBox"
Text="Name"/>
<asp:TextBox ID="NameTextBox" runat="server"
Text='<%#Bind("Name") %>' MaxLength="50" /><br />
<asp:Label runat="server" ID="ProductNumberLabel"
AssociatedControlID="ProductNumberTextBox"
Text="Product Number" />
<asp:TextBox ID="ProductNumberTextBox" runat="server"
Text='<%#Bind("ProductNumber") %>' MaxLength="25" /><br />
</td>
<td>
<asp:Label runat="server" ID="DiscontinuedDateLabel"
AssociatedControlID="DiscontinuedDateTextBox"
Text="Discontinued Date"/>
<asp:TextBox ID="DiscontinuedDateTextBox" runat="server"
Text='<%# Bind("DiscontinuedDate", "{0:d}") %>'
MaxLength="10" /><br />
<asp:Calendar ID="DiscontinuedDateCalendar" runat="server"
SelectedDate='<%# GetDateTime(Eval("DiscontinuedDate")) %>'
OnSelectionChanged="DiscontinuedDateCalendar_OnSelectionChanged" />
</td>
</tr>
</EditItemTemplate>
</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="ProductsDataSource" runat="server"
ConnectionString="<%$ ConnectionStrings:AdventureWorks_DataConnectionString %>"
SelectCommand="SELECT [ProductID], [Name], [ProductNumber], [DiscontinuedDate]
FROM Production.Product"
UpdateCommand="UPDATE Production.Product
SET Name = @Name, ProductNumber = @ProductNumber, DiscontinuedDate = @DiscontinuedDate
WHERE ProductID = @ProductID">
</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()
Message.Text = String.Empty
End Sub
'<Snippet2>
Sub ProductsListView_ItemEditing(ByVal sender As Object, ByVal e As ListViewEditEventArgs)
Dim item As ListViewItem = ProductsListView.Items(e.NewEditIndex)
Dim dateLabel As Label = CType(item.FindControl("DiscontinuedDateLabel"), Label)
If String.IsNullOrEmpty(dateLabel.Text) Then _
Return
'Verify if the item is discontinued.
Dim discontinuedDate As DateTime = DateTime.Parse(dateLabel.Text)
If discontinuedDate < DateTime.Now Then
Message.Text = "You cannot edit a discontinued item."
e.Cancel = True
ProductsListView.SelectedIndex = -1
End If
End Sub
'</Snippet2>
Sub DiscontinuedDateCalendar_OnSelectionChanged(ByVal sender As Object, ByVal e As EventArgs)
Dim dateTextBox As TextBox = _
CType(ProductsListView.EditItem.FindControl("DiscontinuedDateTextBox"), TextBox)
Dim calendarObject As Calendar = CType(sender, Calendar)
dateTextBox.Text = calendarObject.SelectedDate.ToString("d")
End Sub
Function GetDateTime(ByVal dateValue As Object) As DateTime
If dateValue Is DBNull.Value Then
Return DateTime.Now
Else
Return CType(dateValue, DateTime)
End If
End Function
Protected Sub ProductsListView_PagePropertiesChanging(ByVal sender As Object, _
ByVal e As PagePropertiesChangingEventArgs)
' Clears the edit index selection when paging.
ProductsListView.EditIndex = -1
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>ListView Edit Item Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>ListView Edit Item Example</h3>
<asp:Label ID="Message"
ForeColor="Red"
runat="server"/>
<br/>
<asp:ListView ID="ProductsListView"
DataSourceID="ProductsDataSource"
DataKeyNames="ProductID"
OnItemEditing="ProductsListView_ItemEditing"
ConvertEmptyStringToNull="true"
OnPagePropertiesChanging="ProductsListView_PagePropertiesChanging"
runat="server" >
<LayoutTemplate>
<table cellpadding="2" runat="server" id="tblProducts" width="640px">
<tr runat="server" id="itemPlaceholder" />
</table>
<asp:DataPager runat="server" ID="ProductsDataPager" PageSize="12">
<Fields>
<asp:NextPreviousPagerField
ShowFirstPageButton="true" ShowLastPageButton="true"
FirstPageText="|<< " LastPageText=" >>|"
NextPageText=" > " PreviousPageText=" < " />
</Fields>
</asp:DataPager>
</LayoutTemplate>
<ItemTemplate>
<tr runat="server">
<td valign="top">
<asp:LinkButton ID="EditButton" runat="server" Text="Edit" CommandName="Edit" />
</td>
<td valign="top">
<asp:Label ID="NameLabel" runat="server" Text='<%#Eval("Name") %>' />
</td>
<td valign="top">
<asp:Label ID="ProductNumberLabel" runat="server" Text='<%#Eval("ProductNumber") %>' />
</td>
<td>
<asp:Label ID="DiscontinuedDateLabel" runat="server"
Text='<%#Eval("DiscontinuedDate", "{0:d}") %>' />
</td>
</tr>
</ItemTemplate>
<EditItemTemplate>
<tr style="background-color:#ADD8E6">
<td valign="top">
<asp:LinkButton ID="UpdateButton" runat="server"
CommandName="Update" Text="Update" /><br />
<asp:LinkButton ID="CancelButton" runat="server"
CommandName="Cancel" Text="Cancel" />
</td>
<td valign="top" colspan="2">
<asp:Label runat="server" ID="NameLabel"
AssociatedControlID="NameTextBox"
Text="Name"/>
<asp:TextBox ID="NameTextBox" runat="server"
Text='<%#Bind("Name") %>' MaxLength="50" /><br />
<asp:Label runat="server" ID="ProductNumberLabel"
AssociatedControlID="ProductNumberTextBox"
Text="Product Number" />
<asp:TextBox ID="ProductNumberTextBox" runat="server"
Text='<%#Bind("ProductNumber") %>' MaxLength="25" /><br />
</td>
<td>
<asp:Label runat="server" ID="DiscontinuedDateLabel"
AssociatedControlID="DiscontinuedDateTextBox"
Text="Discontinued Date"/>
<asp:TextBox ID="DiscontinuedDateTextBox" runat="server"
Text='<%# Bind("DiscontinuedDate", "{0:d}") %>'
MaxLength="10" /><br />
<asp:Calendar ID="DiscontinuedDateCalendar" runat="server"
SelectedDate='<%# GetDateTime(Eval("DiscontinuedDate")) %>'
OnSelectionChanged="DiscontinuedDateCalendar_OnSelectionChanged" />
</td>
</tr>
</EditItemTemplate>
</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="ProductsDataSource" runat="server"
ConnectionString="<%$ ConnectionStrings:AdventureWorks_DataConnectionString %>"
SelectCommand="SELECT [ProductID], [Name], [ProductNumber], [DiscontinuedDate]
FROM Production.Product"
UpdateCommand="UPDATE Production.Product
SET Name = @Name, ProductNumber = @ProductNumber, DiscontinuedDate = @DiscontinuedDate
WHERE ProductID = @ProductID">
</asp:SqlDataSource>
</form>
</body>
</html>
Comentários
O ItemEditing evento é gerado quando o botão Editar de um item é clicado, mas antes que o ListView item seja colocado no modo de edição. (Um botão Editar é um controle de botão cuja CommandName propriedade está definida como "Editar".) Isso permite que você execute uma rotina personalizada sempre que esse evento ocorrer, como cancelar a operação de edição.
Um ListViewEditEventArgs objeto é passado para o manipulador de eventos, o que permite determinar o índice do item atual. Ele também permite que você indique que a operação de edição deve ser cancelada. Para cancelar a operação de edição, defina a Cancel propriedade do ListViewEditEventArgs objeto como true.
Para obter mais informações sobre como lidar com eventos, consulte Manipulando e gerando eventos.
Aplica-se a
Confira também
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