UpdatePanel Class

 

Enables sections of a page to be partially rendered without a postback.

Namespace:   System.Web.UI
Assembly:  System.Web.Extensions (in System.Web.Extensions.dll)

System.Object
  System.Web.UI.Control
    System.Web.UI.UpdatePanel

public class UpdatePanel : Control, IAttributeAccessor

NameDescription
System_CAPS_pubmethodUpdatePanel()

Initializes a new instance of the UpdatePanel class.

NameDescription
System_CAPS_protpropertyAdapter

Gets the browser-specific adapter for the control.(Inherited from Control.)

System_CAPS_pubpropertyAppRelativeTemplateSourceDirectory

Gets or sets the application-relative virtual directory of the Page or UserControl object that contains this control.(Inherited from Control.)

System_CAPS_pubpropertyAttributes

Gets the cascading style sheet (CSS) attributes collection of the UpdatePanel control.

System_CAPS_pubpropertyBindingContainer

This API supports the product infrastructure and is not intended to be used directly from your code. Gets the control that contains this control's data binding.(Inherited from Control.)

System_CAPS_protpropertyChildControlsCreated

Gets a value that indicates whether the server control's child controls have been created.(Inherited from Control.)

System_CAPS_pubpropertyChildrenAsTriggers

Gets or sets a value that indicates whether postbacks from immediate child controls of an UpdatePanel control update the panel's content.

System_CAPS_pubpropertyClientID

Gets the control ID for HTML markup that is generated by ASP.NET.(Inherited from Control.)

System_CAPS_pubpropertyClientIDMode

Gets or sets the algorithm that is used to generate the value of the ClientID property.(Inherited from Control.)

System_CAPS_protpropertyClientIDSeparator

Gets a character value representing the separator character used in the ClientID property.(Inherited from Control.)

System_CAPS_pubpropertyContentTemplate

Gets or sets the template that defines the content of the UpdatePanel control.

System_CAPS_pubpropertyContentTemplateContainer

Gets a control object to which you can programmatically add child controls.

System_CAPS_protpropertyContext

Gets the HttpContext object associated with the server control for the current Web request.(Inherited from Control.)

System_CAPS_pubpropertyControls

Gets the ControlCollection object that contains the child controls for the UpdatePanel control.(Overrides Control.Controls.)

System_CAPS_pubpropertyDataItemContainer

Gets a reference to the naming container if the naming container implements IDataItemContainer.(Inherited from Control.)

System_CAPS_pubpropertyDataKeysContainer

Gets a reference to the naming container if the naming container implements IDataKeysControl.(Inherited from Control.)

System_CAPS_protpropertyDesignMode

Gets a value indicating whether a control is being used on a design surface.(Inherited from Control.)

System_CAPS_pubpropertyEnableTheming

Gets or sets a value indicating whether themes apply to this control.(Inherited from Control.)

System_CAPS_pubpropertyEnableViewState

Gets or sets a value indicating whether the server control persists its view state, and the view state of any child controls it contains, to the requesting client.(Inherited from Control.)

System_CAPS_protpropertyEvents

Gets a list of event handler delegates for the control. This property is read-only.(Inherited from Control.)

System_CAPS_protpropertyHasChildViewState

Gets a value indicating whether the current server control's child controls have any saved view-state settings.(Inherited from Control.)

System_CAPS_pubpropertyID

Gets or sets the programmatic identifier assigned to the server control.(Inherited from Control.)

System_CAPS_protpropertyIdSeparator

This API supports the product infrastructure and is not intended to be used directly from your code. Gets the character used to separate control identifiers.(Inherited from Control.)

System_CAPS_protpropertyIsChildControlStateCleared

Gets a value indicating whether controls contained within this control have control state.(Inherited from Control.)

System_CAPS_pubpropertyIsInPartialRendering

Gets a value that indicates whether the UpdatePanel control is being updated as a result of an asynchronous postback.

System_CAPS_protpropertyIsTrackingViewState

Gets a value that indicates whether the server control is saving changes to its view state.(Inherited from Control.)

System_CAPS_protpropertyIsViewStateEnabled

Gets a value indicating whether view state is enabled for this control.(Inherited from Control.)

System_CAPS_protpropertyLoadViewStateByID

Gets a value indicating whether the control participates in loading its view state by ID instead of index. (Inherited from Control.)

System_CAPS_pubpropertyNamingContainer

Gets a reference to the server control's naming container, which creates a unique namespace for differentiating between server controls with the same Control.ID property value.(Inherited from Control.)

System_CAPS_pubpropertyPage

Gets a reference to the Page instance that contains the server control.(Inherited from Control.)

System_CAPS_pubpropertyParent

Gets a reference to the server control's parent control in the page control hierarchy.(Inherited from Control.)

System_CAPS_pubpropertyRenderingCompatibility

Gets a value that specifies the ASP.NET version that rendered HTML will be compatible with.(Inherited from Control.)

System_CAPS_pubpropertyRenderMode

Gets or sets a value that indicates whether an UpdatePanel control's content is enclosed in an HTML <div> or <span> element.

System_CAPS_protpropertyRequiresUpdate

Gets a value that indicates whether the content of the UpdatePanel control will be updated.

System_CAPS_pubpropertySite

Gets information about the container that hosts the current control when rendered on a design surface.(Inherited from Control.)

System_CAPS_pubpropertySkinID

Gets or sets the skin to apply to the control.(Inherited from Control.)

System_CAPS_pubpropertyTemplateControl

Gets or sets a reference to the template that contains this control. (Inherited from Control.)

System_CAPS_pubpropertyTemplateSourceDirectory

Gets the virtual directory of the Page or UserControl that contains the current server control.(Inherited from Control.)

System_CAPS_pubpropertyTriggers

Gets an UpdatePanelTriggerCollection object that contains AsyncPostBackTrigger and PostBackTrigger objects that were registered declaratively for the UpdatePanel control.

System_CAPS_pubpropertyUniqueID

Gets the unique, hierarchically qualified identifier for the server control.(Inherited from Control.)

System_CAPS_pubpropertyUpdateMode

Gets or sets a value that indicates when an UpdatePanel control's content is updated.

System_CAPS_pubpropertyValidateRequestMode

Gets or sets a value that indicates whether the control checks client input from the browser for potentially dangerous values.(Inherited from Control.)

System_CAPS_protpropertyViewState

Gets a dictionary of state information that allows you to save and restore the view state of a server control across multiple requests for the same page.(Inherited from Control.)

System_CAPS_protpropertyViewStateIgnoresCase

Gets a value that indicates whether the StateBag object is case-insensitive.(Inherited from Control.)

System_CAPS_pubpropertyViewStateMode

Gets or sets the view-state mode of this control.(Inherited from Control.)

System_CAPS_pubpropertyVisible

Gets or sets a value that indicates whether a server control is rendered as UI on the page.(Inherited from Control.)

NameDescription
System_CAPS_protmethodAddedControl(Control, Int32)

Called after a child control is added to the Controls collection of the Control object.(Inherited from Control.)

System_CAPS_protmethodAddParsedSubObject(Object)

Notifies the server control that an element, either XML or HTML, was parsed, and adds the element to the server control's ControlCollection object.(Inherited from Control.)

System_CAPS_pubmethodApplyStyleSheetSkin(Page)

Applies the style properties defined in the page style sheet to the control.(Inherited from Control.)

System_CAPS_protmethodBeginRenderTracing(TextWriter, Object)

Begins design-time tracing of rendering data.(Inherited from Control.)

System_CAPS_protmethodBuildProfileTree(String, Boolean)

This API supports the product infrastructure and is not intended to be used directly from your code. Gathers information about the server control and delivers it to the Trace property to be displayed when tracing is enabled for the page.(Inherited from Control.)

System_CAPS_protmethodClearCachedClientID()

This API supports the product infrastructure and is not intended to be used directly from your code. Sets the cached ClientID value to null.(Inherited from Control.)

System_CAPS_protmethodClearChildControlState()

Deletes the control-state information for the server control's child controls. (Inherited from Control.)

System_CAPS_protmethodClearChildState()

Deletes the view-state and control-state information for all the server control's child controls.(Inherited from Control.)

System_CAPS_protmethodClearChildViewState()

Deletes the view-state information for all the server control's child controls.(Inherited from Control.)

System_CAPS_protmethodClearEffectiveClientIDMode()

This API supports the product infrastructure and is not intended to be used directly from your code. Sets the ClientIDMode property of the current control instance and of any child controls to Inherit.(Inherited from Control.)

System_CAPS_protmethodCreateChildControls()

Called by the ASP.NET page framework to notify server controls that use composition-based implementation to create any child controls they contain in preparation for posting back or rendering.(Inherited from Control.)

System_CAPS_protmethodCreateContentTemplateContainer()

Creates a Control object that acts as a container for child controls that define the UpdatePanel control's content.

System_CAPS_protmethodCreateControlCollection()

Returns the collection of all controls that are contained in the UpdatePanel control. (Overrides Control.CreateControlCollection().)

System_CAPS_pubmethodDataBind()

Binds a data source to the invoked server control and all its child controls.(Inherited from Control.)

System_CAPS_protmethodDataBind(Boolean)

Binds a data source to the invoked server control and all its child controls with an option to raise the DataBinding event. (Inherited from Control.)

System_CAPS_protmethodDataBindChildren()

Binds a data source to the server control's child controls.(Inherited from Control.)

System_CAPS_pubmethodDispose()

Enables a server control to perform final clean up before it is released from memory.(Inherited from Control.)

System_CAPS_protmethodEndRenderTracing(TextWriter, Object)

Ends design-time tracing of rendering data.(Inherited from Control.)

System_CAPS_protmethodEnsureChildControls()

Determines whether the server control contains child controls. If it does not, it creates child controls.(Inherited from Control.)

System_CAPS_protmethodEnsureID()

Creates an identifier for controls that do not have an identifier assigned.(Inherited from Control.)

System_CAPS_pubmethodEquals(Object)

Determines whether the specified object is equal to the current object.(Inherited from Object.)

System_CAPS_protmethodFinalize()

Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.)

System_CAPS_pubmethodFindControl(String)

Searches the current naming container for a server control with the specified id parameter.(Inherited from Control.)

System_CAPS_protmethodFindControl(String, Int32)

This API supports the product infrastructure and is not intended to be used directly from your code. Searches the current naming container for a server control with the specified id and an integer, specified in the pathOffset parameter, which aids in the search. You should not override this version of the FindControl method.(Inherited from Control.)

System_CAPS_pubmethodFocus()

Sets input focus to a control.(Inherited from Control.)

System_CAPS_protmethodGetDesignModeState()

This API supports the product infrastructure and is not intended to be used directly from your code. Gets design-time data for a control.(Inherited from Control.)

System_CAPS_pubmethodGetHashCode()

Serves as the default hash function. (Inherited from Object.)

System_CAPS_pubmethodGetRouteUrl(Object)

Gets the URL that corresponds to a set of route parameters.(Inherited from Control.)

System_CAPS_pubmethodGetRouteUrl(RouteValueDictionary)

Gets the URL that corresponds to a set of route parameters.(Inherited from Control.)

System_CAPS_pubmethodGetRouteUrl(String, Object)

Gets the URL that corresponds to a set of route parameters and a route name.(Inherited from Control.)

System_CAPS_pubmethodGetRouteUrl(String, RouteValueDictionary)

Gets the URL that corresponds to a set of route parameters and a route name.(Inherited from Control.)

System_CAPS_pubmethodGetType()

Gets the Type of the current instance.(Inherited from Object.)

System_CAPS_pubmethodGetUniqueIDRelativeTo(Control)

Returns the prefixed portion of the UniqueID property of the specified control.(Inherited from Control.)

System_CAPS_pubmethodHasControls()

Determines if the server control contains any child controls.(Inherited from Control.)

System_CAPS_protmethodHasEvents()

Returns a value indicating whether events are registered for the control or any child controls.(Inherited from Control.)

System_CAPS_protmethodInitialize()

Initializes the UpdatePanel control trigger collection if partial-page rendering is enabled.

System_CAPS_protmethodIsLiteralContent()

This API supports the product infrastructure and is not intended to be used directly from your code. Determines if the server control holds only literal content.(Inherited from Control.)

System_CAPS_protmethodLoadControlState(Object)

Restores control-state information from a previous page request that was saved by the SaveControlState method.(Inherited from Control.)

System_CAPS_protmethodLoadViewState(Object)

Restores view-state information from a previous page request that was saved by the SaveViewState method.(Inherited from Control.)

System_CAPS_protmethodMapPathSecure(String)

Retrieves the physical path that a virtual path, either absolute or relative, maps to.(Inherited from Control.)

System_CAPS_protmethodMemberwiseClone()

Creates a shallow copy of the current Object.(Inherited from Object.)

System_CAPS_protmethodOnBubbleEvent(Object, EventArgs)

Determines whether the event for the server control is passed up the page's UI server control hierarchy.(Inherited from Control.)

System_CAPS_protmethodOnDataBinding(EventArgs)

Raises the DataBinding event.(Inherited from Control.)

System_CAPS_protmethodOnInit(EventArgs)

Raises the Init event.(Overrides Control.OnInit(EventArgs).)

System_CAPS_protmethodOnLoad(EventArgs)

Raises the Load event for the UpdatePanel control and invokes the Initialize method when partial-page rendering is not enabled. (Overrides Control.OnLoad(EventArgs).)

System_CAPS_protmethodOnPreRender(EventArgs)

Raises the PreRender event.(Overrides Control.OnPreRender(EventArgs).)

System_CAPS_protmethodOnUnload(EventArgs)

Raises the base Unload event.(Overrides Control.OnUnload(EventArgs).)

System_CAPS_protmethodOpenFile(String)

Gets a Stream used to read a file.(Inherited from Control.)

System_CAPS_protmethodRaiseBubbleEvent(Object, EventArgs)

Assigns any sources of the event and its information to the control's parent.(Inherited from Control.)

System_CAPS_protmethodRemovedControl(Control)

Called after a child control is removed from the Controls collection of the Control object.(Inherited from Control.)

System_CAPS_protmethodRender(HtmlTextWriter)

Raises the Render event.(Overrides Control.Render(HtmlTextWriter).)

System_CAPS_protmethodRenderChildren(HtmlTextWriter)
System_CAPS_pubmethodRenderControl(HtmlTextWriter)

Outputs server control content to a provided HtmlTextWriter object and stores tracing information about the control if tracing is enabled.(Inherited from Control.)

System_CAPS_protmethodRenderControl(HtmlTextWriter, ControlAdapter)

Outputs server control content to a provided HtmlTextWriter object using a provided ControlAdapter object.(Inherited from Control.)

System_CAPS_protmethodResolveAdapter()

Gets the control adapter responsible for rendering the specified control.(Inherited from Control.)

System_CAPS_pubmethodResolveClientUrl(String)

Gets a URL that can be used by the browser.(Inherited from Control.)

System_CAPS_pubmethodResolveUrl(String)

Converts a URL into one that is usable on the requesting client.(Inherited from Control.)

System_CAPS_protmethodSaveControlState()

Saves any server control state changes that have occurred since the time the page was posted back to the server.(Inherited from Control.)

System_CAPS_protmethodSaveViewState()

Saves any server control view-state changes that have occurred since the time the page was posted back to the server.(Inherited from Control.)

System_CAPS_protmethodSetDesignModeState(IDictionary)

Sets design-time data for a control.(Inherited from Control.)

System_CAPS_pubmethodSetRenderMethodDelegate(RenderMethod)

This API supports the product infrastructure and is not intended to be used directly from your code. Assigns an event handler delegate to render the server control and its content into its parent control.(Inherited from Control.)

System_CAPS_pubmethodSetTraceData(Object, Object)

Sets trace data for design-time tracing of rendering data, using the trace data key and the trace data value.(Inherited from Control.)

System_CAPS_pubmethodSetTraceData(Object, Object, Object)

Sets trace data for design-time tracing of rendering data, using the traced object, the trace data key, and the trace data value.(Inherited from Control.)

System_CAPS_pubmethodToString()

Returns a string that represents the current object.(Inherited from Object.)

System_CAPS_protmethodTrackViewState()

Causes tracking of view-state changes to the server control so they can be stored in the server control's StateBag object. This object is accessible through the Control.ViewState property.(Inherited from Control.)

System_CAPS_pubmethodUpdate()

Causes an update of the content of an UpdatePanel control.

NameDescription
System_CAPS_pubeventDataBinding

Occurs when the server control binds to a data source.(Inherited from Control.)

System_CAPS_pubeventDisposed

Occurs when a server control is released from memory, which is the last stage of the server control lifecycle when an ASP.NET page is requested.(Inherited from Control.)

System_CAPS_pubeventInit

Occurs when the server control is initialized, which is the first step in its lifecycle.(Inherited from Control.)

System_CAPS_pubeventLoad

Occurs when the server control is loaded into the Page object.(Inherited from Control.)

System_CAPS_pubeventPreRender

Occurs after the Control object is loaded but prior to rendering.(Inherited from Control.)

System_CAPS_pubeventUnload

Occurs when the server control is unloaded from memory.(Inherited from Control.)

NameDescription
System_CAPS_pubinterfaceSystem_CAPS_privmethodIAttributeAccessor.GetAttribute(String)

Returns an attribute of a Web control by using a specified name.

System_CAPS_pubinterfaceSystem_CAPS_privmethodIAttributeAccessor.SetAttribute(String, String)

Sets the value of the specified control attribute.

System_CAPS_pubinterfaceSystem_CAPS_privmethodIControlDesignerAccessor.GetDesignModeState()

For a description of this member, see IControlDesignerAccessor.GetDesignModeState.(Inherited from Control.)

System_CAPS_pubinterfaceSystem_CAPS_privmethodIControlDesignerAccessor.SetDesignModeState(IDictionary)

For a description of this member, see IControlDesignerAccessor.SetDesignModeState. (Inherited from Control.)

System_CAPS_pubinterfaceSystem_CAPS_privmethodIControlDesignerAccessor.SetOwnerControl(Control)

This API supports the product infrastructure and is not intended to be used directly from your code. For a description of this member, see IControlDesignerAccessor.SetOwnerControl. (Inherited from Control.)

System_CAPS_pubinterfaceSystem_CAPS_privmethodIParserAccessor.AddParsedSubObject(Object)

For a description of this member, see IParserAccessor.AddParsedSubObject. (Inherited from Control.)

System_CAPS_pubinterfaceSystem_CAPS_privpropertyIControlBuilderAccessor.ControlBuilder

For a description of this member, see IControlBuilderAccessor.ControlBuilder. (Inherited from Control.)

System_CAPS_pubinterfaceSystem_CAPS_privpropertyIControlDesignerAccessor.UserData

For a description of this member, see IControlDesignerAccessor.UserData. (Inherited from Control.)

System_CAPS_pubinterfaceSystem_CAPS_privpropertyIDataBindingsAccessor.DataBindings

For a description of this member, see IDataBindingsAccessor.DataBindings. (Inherited from Control.)

System_CAPS_pubinterfaceSystem_CAPS_privpropertyIDataBindingsAccessor.HasDataBindings

For a description of this member, see IDataBindingsAccessor.HasDataBindings. (Inherited from Control.)

System_CAPS_pubinterfaceSystem_CAPS_privpropertyIExpressionsAccessor.Expressions

For a description of this member, see IExpressionsAccessor.Expressions. (Inherited from Control.)

System_CAPS_pubinterfaceSystem_CAPS_privpropertyIExpressionsAccessor.HasExpressions

For a description of this member, see IExpressionsAccessor.HasExpressions. (Inherited from Control.)

NameDescription
System_CAPS_pubmethodFindDataSourceControl()

Returns the data source that is associated with the data control for the specified control.(Defined by DynamicDataExtensions.)

System_CAPS_pubmethodFindFieldTemplate(String)

Returns the field template for the specified column in the specified control's naming container.(Defined by DynamicDataExtensions.)

System_CAPS_pubmethodFindMetaTable()

Returns the metatable object for the containing data control.(Defined by DynamicDataExtensions.)

UpdatePanel controls are a central part of AJAX functionality in ASP.NET. They are used with the ScriptManager control to enable partial-page rendering. Partial-page rendering reduces the need for synchronous postbacks and complete page updates when only part of the page has to be updated. Partial-page rendering improves the user experience because it reduces the screen flicker that occurs during a full-page postback and improves Web page interactivity.

When partial-page rendering is enabled, a control can perform a postback that updates the whole page or an asynchronous postback that updates the content of one or more UpdatePanel controls. Whether a control causes an asynchronous postback and updates an UpdatePanel control depends on the following:

  • If the UpdateMode property of the UpdatePanel control is set to Always, the UpdatePanel control's content is updated on every postback that originates from the page. This includes asynchronous postbacks from controls that are inside other UpdatePanel controls and postbacks from controls that are not inside UpdatePanel controls.

  • If the UpdateMode property is set to Conditional, the UpdatePanel control's content is updated in the following circumstances:

    • When you call the Update method of the UpdatePanel control explicitly.

    • When the UpdatePanel control is nested inside another UpdatePanel control, and the parent panel is updated.

    • When a postback is caused by a control that is defined as a trigger by using the Triggers property of the UpdatePanel control. In this scenario, the control explicitly triggers an update of the panel content. The control can be either inside or outside the UpdatePanel control that the trigger is associated with.

    • When the ChildrenAsTriggers property is set to true and a child control of the UpdatePanel control causes a postback. Child controls of nested UpdatePanel controls do not cause an update to the outer UpdatePanel control unless they are explicitly defined as triggers.

The combination of setting the ChildrenAsTriggers property to false and the UpdateMode property to Always is not allowed and will throw an exception.

When the UpdatePanel control performs an asynchronous post, it adds a custom HTTP header. Some proxies remove this custom HTTP header. If this occurs, the server handles the request as a regular postback, which causes a client error. To resolve this issue, insert a custom form field when you perform asynchronous posts. Then check the header or the custom form field in server code.

You can use multiple UpdatePanel controls to update different page regions independently. When the page that contains one or more UpdatePanel controls is first rendered, all the content of all UpdatePanel controls are rendered and sent to the browser. On subsequent asynchronous postbacks, the content of each UpdatePanel control might not be updated depending on the panel settings and on client or server logic for individual panels.

You can also use UpdatePanel controls in the following scenarios:

  • In user controls.

  • On master and content pages.

  • Nested inside other UpdatePanel controls.

  • Inside templated controls such as the GridView or Repeater controls.

UpdatePanel controls can be added declaratively or programmatically.

You can add an UpdatePanel control programmatically, but you cannot add triggers programmatically. To create trigger-like behavior, you can register a control on the page as an asynchronous postback control. You do this by calling the RegisterAsyncPostBackControl method of the ScriptManager control. You can then create an event handler that runs in response to the asynchronous postback, and in the handler, call the Update method of the UpdatePanel control.

The UpdatePanel control accepts expando attributes. This lets you set a CSS class for the HTMLelements that the controls render. For example, you might create the markup shown in the following example:

<asp:UpdatePanel runat="server" class="myStyle">
</asp:UpdatePanel> 

The markup in the previous example renders HTML similar to the following when the page runs:

<div id="ctl00_MainContent_UpdatePanel1" class="MyStyle">
</div>

<asp:UpdatePanel
    ChildrenAsTriggers="True|False"
    EnableTheming="True|False"
    EnableViewState="True|False"
    ID="string"
    OnDataBinding="DataBinding event handler"
    OnDisposed="Disposed event handler"
    OnInit="Init event handler"
    OnLoad="Load event handler"
    OnPreRender="PreRender event handler"
    OnUnload="Unload event handler"
    RenderMode="Block|Inline"
    runat="server"
    SkinID="string"
    UpdateMode="Always|Conditional"
    Visible="True|False"
>
    <ContentTemplate>
        <!-- child controls -->
    </ContentTemplate>
    <Triggers>
        <asp:AsyncPostBackTrigger 
            ControlID="string"
            EventName="string"
        />
        <asp:PostBackTrigger 
            ControlID="string"
        />
    </Triggers>
</asp:UpdatePanel>

The following examples show different uses of the UpdatePanel control.

Controls Inside an UpdatePanel Control

The following example shows how to put controls inside an UpdatePanel control to reduce screen flicker when you post to the server. In this example, a Calendar and a DropDownList control are inside an UpdatePanel control. By default, the UpdateMode property is Always and the ChildrenAsTriggers property is true. Therefore, child controls of the panel cause an asynchronous postback.


<%@ 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 DropDownSelection_Change(Object sender, EventArgs e)
    {
        Calendar1.DayStyle.BackColor =
            System.Drawing.Color.FromName(ColorList.SelectedItem.Value);
    }

    protected void Calendar1_SelectionChanged(object sender, EventArgs e)
    {
        SelectedDate.Text = 
            Calendar1.SelectedDate.ToString();
    }

</script>

<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
    <title>UpdatePanel Example</title>
</head>
<body>
    <form id="form1" runat="server">
        <div>
            <asp:ScriptManager ID="ScriptManager1" 
                               runat="server" />
            <asp:UpdatePanel ID="UpdatePanel1"
                             runat="server">
                <ContentTemplate>
                    <asp:Calendar ID="Calendar1" 
                                  ShowTitle="True"
                                  OnSelectionChanged="Calendar1_SelectionChanged"
                                  runat="server" />
                    <div>
                        Background:
                        <br />
                        <asp:DropDownList ID="ColorList" 
                                          AutoPostBack="True" 
                                          OnSelectedIndexChanged="DropDownSelection_Change"
                                          runat="server">
                            <asp:ListItem Selected="True" Value="White"> 
                            White </asp:ListItem>
                            <asp:ListItem Value="Silver"> 
                            Silver </asp:ListItem>
                            <asp:ListItem Value="DarkGray"> 
                            Dark Gray </asp:ListItem>
                            <asp:ListItem Value="Khaki"> 
                            Khaki </asp:ListItem>
                            <asp:ListItem Value="DarkKhaki"> D
                            ark Khaki </asp:ListItem>
                        </asp:DropDownList>
                    </div>
                    <br />
                    Selected date:
                    <asp:Label ID="SelectedDate" 
                               runat="server">None.</asp:Label>
                </ContentTemplate>
            </asp:UpdatePanel>
            <br />
        </div>
    </form>
</body>
</html>

Master/Detail Scenario with UpdatePanel Controls

In the following example, an UpdatePanel control is used in a master/detail scenario that shows orders and order details from the Northwind database. One UpdatePanel control contains the GridView control that displays a list of orders. A second UpdatePanel control contains a DetailsView control that displays the details of one order. When you select an order from the first table, details for that order are displayed in the second table. The second table is updated asynchronously based on the selection in the first table. The sorting and paging operations in the orders summary table also cause partial updates.

<%@ 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">

    protected void GridView1_SelectedIndexChanged(object sender, EventArgs e)
    {
        SqlDataSource2.SelectParameters["OrderID"].DefaultValue = 
            GridView1.SelectedDataKey.Value.ToString();
    }
</script>

<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
    <title>UpdatePanel Example</title>
</head>
<body>
    <form id="form1" runat="server">
        <div>
            <asp:ScriptManager ID="ScriptManager1"
                               runat="server" />
            <asp:UpdatePanel ID="OrdersPanel"
                             UpdateMode="Conditional"
                             runat="server">
                <ContentTemplate>
                    <asp:GridView ID="GridView1" 
                                  AllowPaging="True"
                                  AllowSorting="True"
                                  Caption="Orders"
                                  DataKeyNames="OrderID"
                                  DataSourceID="SqlDataSource1"
                                  OnSelectedIndexChanged="GridView1_SelectedIndexChanged"
                                  runat="server" >
                    <Columns>
                    <asp:CommandField ShowSelectButton="True"></asp:CommandField>
                    </Columns>
                    </asp:GridView>
                    <asp:SqlDataSource ID="SqlDataSource1"
                                       runat="server"
                                       ConnectionString="<%$ ConnectionStrings:NorthwindConnectionString %>"
                                       SelectCommand="SELECT [OrderID], [CustomerID], [EmployeeID], [OrderDate] FROM [Orders]">
                    </asp:SqlDataSource>
                </ContentTemplate>
            </asp:UpdatePanel>
            <asp:UpdatePanel ID="OrderDetailsPanel"
                             UpdateMode="Always"
                             runat="server">
                <ContentTemplate>
                    <asp:DetailsView ID="DetailsView1"
                                     Caption="Order Details"
                                     DataKeyNames="OrderID,ProductID"
                                     DataSourceID="SqlDataSource2"
                                     runat="server">
                        <EmptyDataTemplate>
                        <i>Select a row from the Orders table.</i>
                        </EmptyDataTemplate>
                    </asp:DetailsView>
                    <asp:SqlDataSource ID="SqlDataSource2"
                                       ConnectionString="<%$ ConnectionStrings:NorthwindConnectionString %>"
                                       SelectCommand="SELECT [OrderID], [ProductID], [UnitPrice], [Quantity], [Discount] FROM [Order Details] WHERE ([OrderID] = @OrderID)"
                                       runat="server">
                        <SelectParameters>
                            <asp:Parameter Name="OrderID"
                                           Type="Int32" />
                        </SelectParameters>
                    </asp:SqlDataSource>
                </ContentTemplate>
            </asp:UpdatePanel>
        </div>
    </form>
</body>
</html>

If you put a GridView control inside an UpdatePanel control, setting the GridView control's EnableSortingAndPagingCallbacks property to true is not supported. However, because the UpdatePanel control supports asynchronous postbacks, any postbacks that change the GridView control inside an UpdatePanel control cause the same behavior as sorting and paging callbacks.

Using an UpdatePanel Control in a Template

In the following example, an UpdatePanel control is used in the item template of a GridView control. UpdatePanel controls in each data row are generated automatically. Each row's UpdatePanel control contains a Label control to display the quantity of the item in that row and a Button control to decrease and increase the quantity.


<%@ 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">

    private void ChangeQuantity(object sender, int delta)
    {
        Label quantityLabel = (Label)((Button)sender).FindControl("QuantityLabel");
        int currentQuantity = Int32.Parse(quantityLabel.Text);
        currentQuantity = Math.Max(0, currentQuantity + delta);
        quantityLabel.Text = currentQuantity.ToString(System.Globalization.CultureInfo.InvariantCulture);
    }

    private void OnDecreaseQuantity(object sender, EventArgs e)
    {
        ChangeQuantity(sender, -1);
    }

    private void OnIncreaseQuantity(object sender, EventArgs e)
    {
        ChangeQuantity(sender, 1);
    }

    protected void Button1_Click(object sender, EventArgs e)
    {
        StringBuilder sb = new StringBuilder();
        sb.Append("Beverage order:<br/>");
        foreach (GridViewRow row in GridView1.Rows)
        {
            if (row.RowType == DataControlRowType.DataRow)
            {
                Label quantityLabel = (Label)row.FindControl("QuantityLabel");
                int currentQuantity = Int32.Parse(quantityLabel.Text);
                sb.Append(row.Cells[0].Text + " : " + currentQuantity + "<br/>");
            }
        }
        SummaryLabel.Text = sb.ToString();

    }
</script>

<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
    <title>UpdatePanel Inside GridView Template Example </title>
</head>
<body>
    <form id="form1" runat="server">
        <div>
            <asp:ScriptManager ID="ScriptManager1" 
                               runat="server" />
            <asp:GridView ID="GridView1" 
                          AutoGenerateColumns="False"
                          DataSourceID="SqlDataSource1"
                          runat="server">
                <Columns>
                    <asp:BoundField DataField="ProductName" 
                                    HeaderText="ProductName" />
                    <asp:BoundField DataField="UnitPrice"
                                    HeaderText="UnitPrice" />
                    <asp:TemplateField HeaderText="Quantity">
                        <ItemTemplate>
                            <asp:UpdatePanel ID="QuantityUpdatePanel"
                                             UpdateMode="Conditional"
                                             runat="server" >
                                <ContentTemplate>
                                    <asp:Label ID="QuantityLabel"
                                               Text="0"
                                               runat="server" />
                                    <asp:Button ID="DecreaseQuantity"
                                                Text="-"
                                                OnClick="OnDecreaseQuantity"
                                                runat="server" />
                                    <asp:Button ID="IncreaseQuantity" 
                                                Text="+"
                                                OnClick="OnIncreaseQuantity"
                                                runat="server" />
                                </ContentTemplate>
                            </asp:UpdatePanel>
                        </ItemTemplate>
                    </asp:TemplateField>
                </Columns>
            </asp:GridView>            
            <asp:UpdatePanel ID="SummaryUpdatePanel" 
                             UpdateMode="Conditional"
                             runat="server">
                <ContentTemplate>
                    <asp:Button ID="Button1"
                                OnClick="Button1_Click"
                                Text="Get Summary"
                                runat="server" />
                    <br />
                    <asp:Label ID="SummaryLabel"
                               runat="server">
                    </asp:Label>
                </ContentTemplate>
            </asp:UpdatePanel>
            <asp:SqlDataSource ID="SqlDataSource1"
                               ConnectionString="<%$ ConnectionStrings:NorthwindConnectionString %>"
                               SelectCommand="SELECT [ProductName], [UnitPrice] FROM 
                               [Alphabetical list of products] WHERE ([CategoryName] 
                               LIKE '%' + @CategoryName + '%')"
                               runat="server">
                <SelectParameters>
                    <asp:Parameter DefaultValue="Beverages"
                                   Name="CategoryName"
                                   Type="String" />
                </SelectParameters>
            </asp:SqlDataSource>
        </div>
    </form>
</body>
</html>

.NET Framework
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.

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