Defines a control and optional event of the control as an asynchronous postback control trigger that causes an UpdatePanel control to refresh.
Assembly: System.Web.Extensions (in System.Web.Extensions.dll)
Gets or sets the name of the control that triggers an asynchronous postback for an UpdatePanel control.
Gets or sets the postback control event that triggers an UpdatePanel control to be updated.
Determines whether the specified object is equal to the current object.(Inherited from Object.)
Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.)
Serves as the default hash function. (Inherited from Object.)
Returns a value that indicates whether the trigger was invoked.(Overrides UpdatePanelTrigger.HasTriggered().)
Initializes the UpdatePanelTrigger.Initialize().)control and determines whether the event that is named in the trigger exists and is valid.(Overrides
This API supports the product infrastructure and is not intended to be used directly from your code. Raises the event that will trigger a postback and refresh of an UpdatePanel control.
Returns a string representation of the current Object.ToString().)control.(Overrides
Use the UpdatePanel control. Controls that are triggers for an update panel cause a refresh of the panel's content after an asynchronous postback. Defining an asynchronous trigger control is useful in the following scenarios:control to enable controls to be triggers for an
For controls that are outside a panel.
For controls that are inside a panel when the ChildrenAsTriggers property is false.
For controls that are inside nested panels, in order to cause a refresh of parent panels.
The control that thecontrol references must be in the same naming container as the update panel for which it is a trigger. Triggers that are based on controls in other naming containers are not supported.
Add UpdatePanel control. The ControlID property is required, but the EventName property is optional. If the EventName property is not specified, the DefaultEventAttribute attribute of the control is used to determine the default event. For example, the default event for the Button control is the Click event. The EventName property is case-insensitive.controls either by using the UpdatePanelTrigger Collection Editor dialog box in the designer or by creating a Triggers element declaratively in the
You can also reference a naming container as a trigger. In that case, all child controls in the container that cause a postback are considered triggers for the UpdatePanel control.
If you define a control using both PostBackTrigger and , an exception is thrown.
The following example shows how to add an Button control that is outside an UpdatePanel control lets users enter a search term to find in the Products table of the Northwind database. A GridView control that is inside the UpdatePanel control shows the results. The Button control is specified as an asynchronous trigger for the UpdatePanel control.control declaratively. A
<%@ 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"> Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) SqlDataSource1.SelectParameters("SearchTerm").DefaultValue = _ Server.HtmlEncode(TextBox1.Text) Label1.Text = "Searching for '" & _ Server.HtmlEncode(TextBox1.Text) & "'" End Sub </script> <html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> <title>AsyncPostBackTrigger Example</title> </head> <body> <form id="form1" defaultbutton="Button1" defaultfocus="TextBox1" runat="server"> <div> <asp:ScriptManager ID="ScriptManager1" runat="server" /> <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox> <asp:Button ID="Button1" Text="Submit" OnClick="Button1_Click" runat="server" /> <asp:UpdatePanel ID="UpdatePanel1" UpdateMode="Conditional" runat="server"> <Triggers> <asp:AsyncPostBackTrigger ControlID="Button1" /> </Triggers> <ContentTemplate> <hr /> <asp:Label ID="Label1" runat="server"/> <br /> <asp:GridView ID="GridView1" runat="server" AllowPaging="True" AllowSorting="True" DataSourceID="SqlDataSource1"> <EmptyDataTemplate> Enter a search term. </EmptyDataTemplate> </asp:GridView> <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:NorthwindConnectionString %>" SelectCommand="SELECT [ProductName], [UnitsInStock] FROM [Alphabetical list of products] WHERE ([ProductName] LIKE '%' + @SearchTerm + '%')"> <SelectParameters> <asp:Parameter Name="SearchTerm" Type="String" /> </SelectParameters> </asp:SqlDataSource> </ContentTemplate> </asp:UpdatePanel> </div> </form> </body> </html>
Available since 3.5
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.