GridViewEditEventHandler Delegar
Definição
Importante
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Representa o método que manipula o evento RowEditing de um controle GridView.
public delegate void GridViewEditEventHandler(System::Object ^ sender, GridViewEditEventArgs ^ e);public delegate void GridViewEditEventHandler(object sender, GridViewEditEventArgs e);type GridViewEditEventHandler = delegate of obj * GridViewEditEventArgs -> unitPublic Delegate Sub GridViewEditEventHandler(sender As Object, e As GridViewEditEventArgs)Parâmetros
- sender
- Object
A fonte do evento.
Um objeto de GridViewEditEventArgs que contém os dados do evento.
Exemplos
O exemplo a seguir demonstra como adicionar programaticamente um GridViewEditEventHandler delegado ao RowEditing 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 control.
GridView customersGridView = new GridView();
// Set the GridView control's properties.
customersGridView.ID = "CustomersGridView";
customersGridView.DataSourceID = "CustomersSqlDataSource";
customersGridView.AutoGenerateColumns = true;
customersGridView.AutoGenerateEditButton = true;
customersGridView.AllowPaging = true;
customersGridView.DataKeyNames = new String[] { "CustomerID" };
// Programmatically register the event-handling method.
customersGridView.RowEditing += new GridViewEditEventHandler(this.CustomersGridView_RowEditing);
// Add the GridView control to the Controls collection
// of the PlaceHolder control.
GridViewPlaceHolder.Controls.Add(customersGridView);
}
void CustomersGridView_RowEditing(Object sender, GridViewEditEventArgs e)
{
// User the sender parameter to retrieve the GridView control
// that raised the event.
GridView customersGridView = (GridView)sender;
// Get the country for the row being edited. For this example, the
// country is contained in the seventh column (index 6).
String country = customersGridView.Rows[e.NewEditIndex].Cells[6].Text;
// For this example, cancel the edit operation if the user attempts
// to edit the record of a customer from the USA.
if (country == "USA")
{
// Cancel the edit operation.
e.Cancel = true;
Message.Text = "You cannot edit this record.";
}
else
{
Message.Text = "";
}
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>GridViewEditEventHandler Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>GridViewEditEventHandler 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 Northwind sample database. Use an ASP.NET -->
<!-- expression to retrieve the connection string value -->
<!-- from the Web.config file. -->
<asp:sqldatasource id="CustomersSqlDataSource"
selectcommand="Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]"
updatecommand="Update Customers SET CompanyName=@CompanyName, Address=@Address, City=@City, PostalCode=@PostalCode, Country=@Country WHERE (CustomerID = @CustomerID)"
connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>"
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 control.
Dim customersGridView As New GridView()
' Set the GridView control's properties.
customersGridView.ID = "CustomersGridView"
customersGridView.DataSourceID = "CustomersSqlDataSource"
customersGridView.AutoGenerateColumns = True
customersGridView.AutoGenerateEditButton = True
customersGridView.AllowPaging = True
Dim keyArray() As String = {"CustomerID"}
customersGridView.DataKeyNames = keyArray
' Programmatically register the event-handling method.
AddHandler customersGridView.RowEditing, AddressOf CustomersGridView_RowEditing
' Add the GridView control to the Controls collection
' of the PlaceHolder control.
GridViewPlaceHolder.Controls.Add(customersGridView)
End Sub
Sub CustomersGridView_RowEditing(ByVal sender As Object, ByVal e As GridViewEditEventArgs)
' User the sender parameter to retrieve the GridView control
' that raised the event.
Dim customersGridView As GridView = CType(sender, GridView)
' Get the country for the row being edited. For this example, the
' country is contained in the seventh column (index 6).
Dim country As String = customersGridView.Rows(e.NewEditIndex).Cells(6).Text
' For this example, cancel the edit operation if the user attempts
' to edit the record of a customer from the USA.
If country = "USA" Then
' Cancel the edit operation.
e.Cancel = True
Message.Text = "You cannot edit this record."
Else
Message.Text = ""
End If
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>GridViewEditEventHandler Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>GridViewEditEventHandler 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 Northwind sample database. Use an ASP.NET -->
<!-- expression to retrieve the connection string value -->
<!-- from the Web.config file. -->
<asp:sqldatasource id="CustomersSqlDataSource"
selectcommand="Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]"
updatecommand="Update Customers SET CompanyName=@CompanyName, Address=@Address, City=@City, PostalCode=@PostalCode, Country=@Country WHERE (CustomerID = @CustomerID)"
connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>"
runat="server">
</asp:sqldatasource>
</form>
</body>
</html>
O exemplo a seguir demonstra como adicionar declarativamente um GridViewEditEventHandler delegado ao RowEditing 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_RowEditing(Object sender, GridViewEditEventArgs e)
{
// Get the country for the row being edited. For this example, the
// country is contained in the seventh column (index 6).
String country = CustomersGridView.Rows[e.NewEditIndex].Cells[6].Text;
// For this example, cancel the edit operation if the user attempts
// to edit the record of a customer from the Unites States.
if (country == "USA")
{
// Cancel the edit operation.
e.Cancel = true;
Message.Text = "You cannot edit this record.";
}
else
{
Message.Text = "";
}
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>GridView RowEditing Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>GridView RowEditing Example</h3>
<asp:label id="Message"
forecolor="Red"
runat="server"/>
<br/>
<!-- The GridView control automatically sets the columns -->
<!-- specified in the datakeynames property as read-only. -->
<!-- No input controls are rendered for these columns in -->
<!-- edit mode. -->
<asp:gridview id="CustomersGridView"
datasourceid="CustomersSqlDataSource"
autogeneratecolumns="true"
autogenerateeditbutton="true"
allowpaging="true"
datakeynames="CustomerID"
onrowediting="CustomersGridView_RowEditing"
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="CustomersSqlDataSource"
selectcommand="Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]"
updatecommand="Update Customers SET CompanyName=@CompanyName, Address=@Address, City=@City, PostalCode=@PostalCode, Country=@Country WHERE (CustomerID = @CustomerID)"
connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>"
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 CustomersGridView_RowEditing(ByVal sender As Object, ByVal e As GridViewEditEventArgs)
' Get the country for the row being edited. For this example, the
' country is contained in the seventh column (index 6).
Dim country As String = CustomersGridView.Rows(e.NewEditIndex).Cells(6).Text
' For this example, cancel the edit operation if the user attempts
' to edit the record of a customer from the United States.
If country = "USA" Then
' Cancel the edit operation.
e.Cancel = True
Message.Text = "You cannot edit this record."
Else
Message.Text = ""
End If
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>GridView RowEditing Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>GridView RowEditing Example</h3>
<asp:label id="Message"
forecolor="Red"
runat="server"/>
<br/>
<!-- The GridView control automatically sets the columns -->
<!-- specified in the datakeynames property as read-only. -->
<!-- No input controls are rendered for these columns in -->
<!-- edit mode. -->
<asp:gridview id="CustomersGridView"
datasourceid="CustomersSqlDataSource"
autogeneratecolumns="true"
autogenerateeditbutton="true"
allowpaging="true"
datakeynames="CustomerID"
onrowediting="CustomersGridView_RowEditing"
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="CustomersSqlDataSource"
selectcommand="Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]"
updatecommand="Update Customers SET CompanyName=@CompanyName, Address=@Address, City=@City, PostalCode=@PostalCode, Country=@Country WHERE (CustomerID = @CustomerID)"
connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>"
runat="server">
</asp:sqldatasource>
</form>
</body>
</html>
Comentários
O RowEditing evento é gerado quando um botão Editar (um botão com sua CommandName propriedade definida como "Editar") é clicado, mas antes que o GridView controle entre no modo de edição. Isso permite que você forneça um método de manipulação de eventos que executa uma rotina personalizada, como cancelar a operação de edição, sempre que esse evento ocorrer.
Ao criar um GridViewEditEventHandler 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
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