When working in the markup editor in Visual Studio, you may notice (from Intelli Sense) that there are two child elements of an , and can specify any Control within the current unit of encapsulation (for instance, if your Update Panel control resides within a Web User Control, you should not attempt to reference a Control on the Page on which the User Control will reside).
The Update Panel control is probably the most important control in the ASP. It will AJAX'ify controls contained within it, allowing partial rendering of the area.
NET profiling API), and an extensive client-side API designed to mirror many of the control schemes seen in the ASP. This whitepaper examines the XML Triggers functionality of the ASP. XML Triggers give granular control over the components that can cause partial rendering for specific Update Panel controls. NET AJAX Extensions, previously an add-on assembly targeted at ASP. Triggers for a given Update Panel, by default, automatically include any child controls that invoke a postback, including (for example) Text Box controls that have their event.
This whitepaper is based on the Beta 2 release of the . Remember that Pages are stateless, and so you should re-register these controls every time they are created.
Note that when Update Panel controls are nested, when the Update Mode is set to Conditional, if the child Update Panel is triggered, but the parent is not, then only the child Update Panel will refresh.
However, if the parent Update Panel is refreshed, then the child Update Panel will also be refreshed.
One of which is the Triggers element, which specifies the controls on the page (or the user control, if you are using one) that will trigger a partial render of the Update Panel control in which the element resides. NET technology brings an object-oriented and event-driven programming model and unites it with the benefits of compiled code.
However, its server-side processing model has several drawbacks inherent in the technology, many of which can be addressed by the new features included in the Microsoft ASP. These extensions enable many new rich client features, including partial rendering of pages without requiring a full page refresh, the ability to access Web Services via client script (including the ASP. This whitepaper also assumes that you will be working with Visual Studio 2008, not Visual Web Developer Express, and will provide walkthroughs according to the user interface of Visual Studio (although code listings will be entirely compatible regardless of development environment).
Between writing my book and some of my more recent projects, I haven't had a chance to write a lot of code.Only the contents of the Update Panel control will be updated. NET AJAX controls require specific settings in a web.config file in order to function correctly.If you try to work with one of these controls, and your website doesn't contain the required web.config file, errors appear in the This walkthrough introduced the basic concepts of using a Timer control and an Update Panel control to enable partial-page updates.Now, if it takes awhile for the server to process the postback (e.g.complex rules or badly written code ), the user may not realize that the server is processing the request.This can lead to all kinds of issues with users that are not savvy or familiar with web applications (multiple clicks, moving off the page, etc.).