Source Code: Microsoft AJAX Series Part 6 - PageRequestManager
Microsoft AJAX Series Part 6 - PageRequestManager
This is the sixth in a series of blog posts about Microsoft ASP.NET AJAX, a new web development technology from Microsoft.
Click these links to view previous posts in this series: Post 1, Post 2, Post 3, Post 4 and Post 5
This article introduces the Microsoft Ajax PageRequestManager object and demonstrates how to handle its pageLoaded event to it trigger an animation when a page is updated after an asynchronous post back.
PageRequestManager Overview
The PageRequestManager class in the Microsoft AJAX Library manages partial-page rendering on the client.
When you have a ScriptManager and one or more UpdatePanel controls on the page, the page is automatically enabled for partial-page rendering.
The PageRequestManager exposes properties, methods, and events that allow you to customize the partial-page rendering experience with client script.
- Provide custom error message handling for partial-page rendering.
- Control multiple asynchronous postbacks.
- Display status messages during asynchronous postbacks.
- Access the underlying request and response objects used in an asynchronous postback.
Partial-Page Rendering Event Handling
During page processing (both postbacks and asynchronous postbacks), you can handle DOM events to run custom script.
However, these DOM events do not enable you to access information or control the behavior during asynchronous postbacks and during partial-page updates that occur between the load and unload of the page in the browser.
The PageRequestManager class exposes the following events that enable you to customize partial-page rendering:
- initializeRequest
- beginRequest
- pageLoading
- pageLoaded
- endRequest
About the Source Code
The source code implements an ASP.NET 2.0 web application that shows how you can use the pageLoaded event of the PageRequestManager class to animate an UpdatePanel control when the page is updated after an asynchronous postback.
In this web page shown above, users can select a date and enter an email address into a simple form to make a ticket request. When certain elements postback from the page ( (1) above), the panel is animated briefly to notify the user that the date value was entered into the text box. The page contains a popup that displays a Calendar control. The calendar is displayed or hidden using the control's Visible property. Hiding, showing, or selecting dates in the calendar does not cause the entire page to be refreshed, because the Calendar control is inside an UpdatePanel control.
The source code included with this post (see download link above) includes additional comments about the example.
The source code was created with ASP.NET AJAX 1.0 Beta 2. For more information and FREE Microsoft ASP.NET Ajax installers visit -> The Official Microsoft ASP.NET AJAX Website
mike mcintyre http://www.getdotnetcode.com