GridViewUpdatedEventHandler Делегат
Определение
Важно!
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Представляет метод, обрабатывающий событие RowUpdated элемента управления GridView.
public delegate void GridViewUpdatedEventHandler(System::Object ^ sender, GridViewUpdatedEventArgs ^ e);
public delegate void GridViewUpdatedEventHandler(object sender, GridViewUpdatedEventArgs e);
type GridViewUpdatedEventHandler = delegate of obj * GridViewUpdatedEventArgs -> unit
Public Delegate Sub GridViewUpdatedEventHandler(sender As Object, e As GridViewUpdatedEventArgs)
Параметры
- sender
- Object
Источник события.
Объект GridViewUpdatedEventArgs, содержащий данные события.
Примеры
В следующем примере показано, как программным способом GridViewUpdatedEventHandler добавить делегат в RowUpdated событие GridView элемента управления .
<%@ 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[1] { "CustomerID" };
// Programmatically register the event-handling method
// for the RowDeleted event of the GridView control.
customersGridView.RowUpdated += new GridViewUpdatedEventHandler(this.CustomersGridView_RowUpdated);
customersGridView.RowCancelingEdit += new GridViewCancelEditEventHandler(this.CustomersGridView_RowCancelingEdit);
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_RowUpdated(Object sender, GridViewUpdatedEventArgs e)
{
// Indicate whether the update operation succeeded.
if(e.Exception == null)
{
Message.Text = "Row updated successfully.";
}
else
{
e.ExceptionHandled = true;
Message.Text = "An error occurred while attempting to update the row.";
}
}
void CustomersGridView_RowCancelingEdit(Object sender, GridViewCancelEditEventArgs e)
{
// The update operation was canceled. Clear the message label.
Message.Text = "";
}
void CustomersGridView_RowEditing(Object sender, GridViewEditEventArgs e)
{
// The GridView control is entering edit mode. Clear the message label.
Message.Text = "";
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>GridViewUpdatedEventHandler Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>GridViewUpdatedEventHandler 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
' for the RowDeleted event of the GridView control.
AddHandler customersGridView.RowUpdated, AddressOf CustomersGridView_RowUpdated
AddHandler customersGridView.RowCancelingEdit, AddressOf CustomersGridView_RowCancelingEdit
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_RowUpdated(ByVal sender As Object, ByVal e As GridViewUpdatedEventArgs)
' Indicate whether the update operation succeeded.
If e.Exception Is Nothing Then
Message.Text = "Row updated successfully."
Else
e.ExceptionHandled = True
Message.Text = "An error occurred while attempting to update the row."
End If
End Sub
Sub CustomersGridView_RowCancelingEdit(ByVal sender As Object, ByVal e As GridViewCancelEditEventArgs)
' The update operation was canceled. Clear the message label.
Message.Text = ""
End Sub
Sub CustomersGridView_RowEditing(ByVal sender As Object, ByVal e As GridViewEditEventArgs)
' The GridView control is entering edit mode. Clear the message label.
Message.Text = ""
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>GridView GridViewUpdatedEventHandler Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>GridView GridViewUpdatedEventHandler 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>
В следующем примере показано, как декларативно добавить GridViewUpdatedEventHandler делегат в RowUpdated событие GridView элемента управления .
<%@ 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_RowUpdated(Object sender, GridViewUpdatedEventArgs e)
{
// Indicate whether the update operation succeeded.
if(e.Exception == null)
{
Message.Text = "Row updated successfully.";
}
else
{
e.ExceptionHandled = true;
Message.Text = "An error occurred while attempting to update the row.";
}
}
void CustomersGridView_RowCancelingEdit(Object sender, GridViewCancelEditEventArgs e)
{
// The update operation was canceled. Clear the message label.
Message.Text = "";
}
void CustomersGridView_RowEditing(Object sender, GridViewEditEventArgs e)
{
// The GridView control is entering edit mode. Clear the message label.
Message.Text = "";
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>GridView RowUpdated Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>GridView RowUpdated 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"
onrowupdated="CustomersGridView_RowUpdated"
onrowcancelingedit="CustomersGridView_RowCancelingEdit"
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_RowUpdated(ByVal sender As Object, ByVal e As GridViewUpdatedEventArgs)
' Indicate whether the update operation succeeded.
If e.Exception Is Nothing Then
Message.Text = "Row updated successfully."
Else
e.ExceptionHandled = True
Message.Text = "An error occurred while attempting to update the row."
End If
End Sub
Sub CustomersGridView_RowCancelingEdit(ByVal sender As Object, ByVal e As GridViewCancelEditEventArgs)
' The update operation was canceled. Clear the message label.
Message.Text = ""
End Sub
Sub CustomersGridView_RowEditing(ByVal sender As Object, ByVal e As GridViewEditEventArgs)
' The GridView control is entering edit mode. Clear the message label.
Message.Text = ""
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>GridView RowUpdated Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>GridView RowUpdated 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"
onrowupdated="CustomersGridView_RowUpdated"
onrowcancelingedit="CustomersGridView_RowCancelingEdit"
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>
Комментарии
Элемент GridView управления вызывает RowUpdated событие при нажатии кнопки "Обновить" (кнопки со свойством CommandName
"Обновить") в элементе управления, но после GridView обновления записи элементом управления. Это позволяет предоставить метод обработки событий, который выполняет настраиваемую подпрограмму, например проверку результатов операции обновления при каждом возникновении этого события.
При создании делегата GridViewUpdatedEventHandler необходимо указать метод, обрабатывающий событие. Чтобы связать событие с обработчиком событий, нужно добавить в событие экземпляр делегата. Обработчик событий вызывается всякий раз, когда происходит событие, если делегат не удален. Дополнительные сведения о делегатах обработчика событий см. в разделе Обработка и вызов событий.
Методы расширения
GetMethodInfo(Delegate) |
Получает объект, представляющий метод, представленный указанным делегатом. |