GridViewPageEventHandler Delegát
Definice
Důležité
Některé informace platí pro předběžně vydaný produkt, který se může zásadně změnit, než ho výrobce nebo autor vydá. Microsoft neposkytuje žádné záruky, výslovné ani předpokládané, týkající se zde uváděných informací.
Představuje metodu, která zpracovává PageIndexChanging událost GridView ovládacího prvku.
public delegate void GridViewPageEventHandler(System::Object ^ sender, GridViewPageEventArgs ^ e);public delegate void GridViewPageEventHandler(object sender, GridViewPageEventArgs e);type GridViewPageEventHandler = delegate of obj * GridViewPageEventArgs -> unitPublic Delegate Sub GridViewPageEventHandler(sender As Object, e As GridViewPageEventArgs)Parametry
- sender
- Object
Zdroj události
Objekt GridViewPageEventArgs , který obsahuje data události.
Příklady
Následující příklad ukazuje, jak programově přidat GridViewPageEventHandler delegáta k PageIndexChanging události GridView ovládacího prvku.
<%@ 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 object's properties.
customersGridView.ID = "CustomersGridView";
customersGridView.DataSourceID = "CustomersSource";
customersGridView.AutoGenerateColumns = true;
customersGridView.EmptyDataText = "No data available.";
customersGridView.AllowPaging = true;
customersGridView.AutoGenerateEditButton = true;
customersGridView.PagerSettings.Mode = PagerButtons.Numeric;
customersGridView.PagerSettings.Position = PagerPosition.Bottom;
customersGridView.PagerSettings.PageButtonCount = 10;
customersGridView.PagerStyle.BackColor = System.Drawing.Color.LightBlue;
customersGridView.DataKeyNames = new String[] { "CustomerID" };
// Programmatically register the event-handling methods.
customersGridView.PageIndexChanging += new GridViewPageEventHandler(this.CustomersGridView_PageIndexChanging);
customersGridView.RowCancelingEdit += new GridViewCancelEditEventHandler(this.CustomersGridView_RowCancelingEdit);
// Add the GridView control to the Controls collection
// of the PlaceHolder control.
GridViewPlaceHolder.Controls.Add(customersGridView);
}
void CustomersGridView_PageIndexChanging(Object sender, GridViewPageEventArgs e)
{
// User the sender parameter to retrieve the GridView control
// that raised the event.
GridView customersGridView = (GridView)sender;
// Cancel the paging operation if the user attempts to navigate
// to another page while the GridView control is in edit mode.
if (customersGridView.EditIndex != -1)
{
// Use the cancel property to cancel the paging operation.
e.Cancel = true;
// Display an error message.
int newPageNumber = e.NewPageIndex + 1;
Message.Text = "Please update the record before moving to page " +
newPageNumber.ToString() + ".";
}
else
{
// Clear the error message.
Message.Text = "";
}
}
void CustomersGridView_RowCancelingEdit(Object sender, GridViewCancelEditEventArgs e)
{
// Clear the error message.
Message.Text = "";
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>GridViewPageEventHandler Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>GridViewPageEventHandler 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="CustomersSource"
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"/>
</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 object's properties.
customersGridView.ID = "CustomersGridView"
customersGridView.DataSourceID = "CustomersSource"
customersGridView.AutoGenerateColumns = True
customersGridView.EmptyDataText = "No data available."
customersGridView.AllowPaging = True
customersGridView.AutoGenerateEditButton = True
customersGridView.PagerSettings.Mode = PagerButtons.Numeric
customersGridView.PagerSettings.Position = PagerPosition.Bottom
customersGridView.PagerSettings.PageButtonCount = 10
customersGridView.PagerStyle.BackColor = System.Drawing.Color.LightBlue
Dim keyArray() As String = {"CustomerID"}
customersGridView.DataKeyNames = keyArray
' Programmatically register the event-handling methods.
AddHandler customersGridView.PageIndexChanging, AddressOf CustomersGridView_PageIndexChanging
AddHandler customersGridView.RowCancelingEdit, AddressOf CustomersGridView_RowCancelingEdit
' Add the GridView control to the Controls collection
' of the PlaceHolder control.
GridViewPlaceHolder.Controls.Add(customersGridView)
End Sub
Sub CustomersGridView_PageIndexChanging(ByVal sender As Object, ByVal e As GridViewPageEventArgs)
' User the sender parameter to retrieve the GridView control
' that raised the event.
Dim customersGridView As GridView = CType(sender, GridView)
' Cancel the paging operation if the user attempts to navigate
' to another page while the GridView control is in edit mode.
If customersGridView.EditIndex <> -1 Then
' Use the cancel property to cancel the paging operation.
e.Cancel = True
' Display an error message.
Dim newPageNumber As Integer = e.NewPageIndex + 1
Message.Text = "Please update the record before moving to page " & _
newPageNumber.ToString() & "."
Else
' Clear the error message.
Message.Text = ""
End If
End Sub
Sub CustomersGridView_RowCancelingEdit(ByVal sender As Object, ByVal e As GridViewCancelEditEventArgs)
' Clear the error message.
Message.Text = ""
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>GridViewPageEventHandler Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>GridViewPageEventHandler 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="CustomersSource"
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"/>
</form>
</body>
</html>
Následující příklad ukazuje, jak deklarativně přidat GridViewPageEventHandler delegáta k PageIndexChanging události GridView ovládacího prvku.
<%@ 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_PageIndexChanging(Object sender, GridViewPageEventArgs e)
{
// Cancel the paging operation if the user attempts to navigate
// to another page while the GridView control is in edit mode.
if (CustomersGridView.EditIndex != -1)
{
// Use the Cancel property to cancel the paging operation.
e.Cancel = true;
// Display an error message.
int newPageNumber = e.NewPageIndex + 1;
Message.Text = "Please update the record before moving to page " +
newPageNumber.ToString() + ".";
}
else
{
// Clear the error message.
Message.Text = "";
}
}
void CustomersGridView_RowCancelingEdit(Object sender, GridViewCancelEditEventArgs e)
{
// Clear the error message.
Message.Text = "";
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>GridView PageIndexChanging Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>GridView PageIndexChanging Example</h3>
<asp:label id="Message"
forecolor="Red"
runat="server"/>
<br/>
<asp:gridview id="CustomersGridView"
datasourceid="CustomersSource"
autogeneratecolumns="true"
emptydatatext="No data available."
allowpaging="true"
autogenerateeditbutton="true"
datakeynames="CustomerID"
onpageindexchanging="CustomersGridView_PageIndexChanging"
onrowcancelingedit="CustomersGridView_RowCancelingEdit"
runat="server">
<pagersettings mode="Numeric"
position="Bottom"
pagebuttoncount="10"/>
<pagerstyle backcolor="LightBlue"/>
</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]"
updatecommand="Update Customers SET CompanyName=@CompanyName, Address=@Address, City=@City, PostalCode=@PostalCode, Country=@Country WHERE (CustomerID = @CustomerID)"
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_PageIndexChanging(ByVal sender As Object, ByVal e As GridViewPageEventArgs)
' Cancel the paging operation if the user attempts to navigate
' to another page while the GridView control is in edit mode.
If CustomersGridView.EditIndex <> -1 Then
' Use the Cancel property to cancel the paging operation.
e.Cancel = True
' Display an error message.
Dim newPageNumber As Integer = e.NewPageIndex + 1
Message.Text = "Please update the record before moving to page " & _
newPageNumber.ToString() & "."
Else
' Clear the error message.
Message.Text = ""
End If
End Sub
Sub CustomersGridView_RowCancelingEdit(ByVal sender As Object, ByVal e As GridViewCancelEditEventArgs)
' Clear the error message.
Message.Text = ""
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>GridView PageIndexChanging Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>GridView PageIndexChanging Example</h3>
<asp:label id="Message"
forecolor="Red"
runat="server"/>
<br/>
<asp:gridview id="CustomersGridView"
datasourceid="CustomersSource"
autogeneratecolumns="true"
emptydatatext="No data available."
allowpaging="true"
autogenerateeditbutton="true"
datakeynames="CustomerID"
onpageindexchanging="CustomersGridView_PageIndexChanging"
onrowcancelingedit="CustomersGridView_RowCancelingEdit"
runat="server">
<pagersettings mode="Numeric"
position="Bottom"
pagebuttoncount="10"/>
<pagerstyle backcolor="LightBlue"/>
</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]"
updatecommand="Update Customers SET CompanyName=@CompanyName, Address=@Address, City=@City, PostalCode=@PostalCode, Country=@Country WHERE (CustomerID = @CustomerID)"
connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>"
runat="server"/>
</form>
</body>
</html>
Poznámky
Ovládací GridView prvek vyvolá PageIndexChanging událost, když se klikne na tlačítko pageru (tlačítko s CommandName jeho vlastností nastavenou na "Stránka") v rámci ovládacího prvku, ale před tím, než GridView ovládací prvek zpracuje operaci stránkování. To vám umožní poskytnout metodu zpracování událostí, která provádí vlastní rutinu, jako je například zrušení operace stránkování, kdykoli dojde k této události.
Poznámka
Tlačítka pageru se obvykle nacházejí v řádku GridView pager ovládacího prvku.
Při vytváření delegáta GridViewPageEventHandler identifikujete metodu, která bude zpracovávat událost. Pokud chcete událost přidružit k obslužné rutině události, přidejte do události instanci delegáta. Obslužná rutina události je volána při každém výskytu události, dokud neodeberete delegáta. Další informace o delegátech obslužné rutiny událostí najdete v tématu Zpracování a vyvolávání událostí.
Metody rozšíření
| GetMethodInfo(Delegate) |
Získá objekt, který představuje metodu reprezentovanou zadaným delegátem. |
Platí pro
Viz také
Spolupracujte s námi na GitHubu
Zdroj tohoto obsahu najdete na GitHubu, kde můžete také vytvářet a kontrolovat problémy a žádosti o přijetí změn. Další informace najdete v našem průvodci pro přispěvatele.
