AJAX stands for Asynchronous JavaScript and XML. This is a cross platform technology which speeds up response time. The AJAX server controls add script to the page which is executed and processed by the browser.
However like other ASP.NET server controls, these AJAX server controls also can have methods and event handlers associated with them, which are processed on the server side.
The control toolbox in the Visual Studio IDE contains a group of controls called the 'AJAX Extensions'
Examples of applications using AJAX: Google Maps, Gmail, Youtube, and Facebook tabs.
The ScriptManager Control
The ScriptManager control is the most important control and must be present on the page for other controls to work.
It has the basic syntax:
ID="ScriptManager1" runat="server";
If you create an 'Ajax Enabled site' or add an 'AJAX Web Form' from the 'Add Item' dialog box, the web form automatically contains the script manager control. The ScriptManager control takes care of the client-side script for all the server side controls.
The UpdatePanel Control : The UpdatePanel control is a container control and derives from the Control class. It acts as a container for the child controls within it and does not have its own interface.
For example, if a button control is inside the update panel and it is clicked, only the controls within the update panel will be affected, the controls on the other parts of the page will not be affected.
The UpdateProgress Control
The UpdateProgress control provides a sort of feedback on the browser while one or more update panel controls are being updated. It provides a visual acknowledgement like "Loading page...", indicating the work is in progress.
The Timer Control
The timer control is used to initiate the post back automatically. This could be done in two ways :
(1) Setting the Triggers property of the UpdatePanel control:
(2) Placing a timer control directly inside the UpdatePanel to act as a child control trigger. A single timer can be the trigger for multiple UpdatePanels.
However like other ASP.NET server controls, these AJAX server controls also can have methods and event handlers associated with them, which are processed on the server side.
The control toolbox in the Visual Studio IDE contains a group of controls called the 'AJAX Extensions'
Examples of applications using AJAX: Google Maps, Gmail, Youtube, and Facebook tabs.
The ScriptManager Control
The ScriptManager control is the most important control and must be present on the page for other controls to work.
It has the basic syntax:
ID="ScriptManager1" runat="server";
If you create an 'Ajax Enabled site' or add an 'AJAX Web Form' from the 'Add Item' dialog box, the web form automatically contains the script manager control. The ScriptManager control takes care of the client-side script for all the server side controls.
The UpdatePanel Control : The UpdatePanel control is a container control and derives from the Control class. It acts as a container for the child controls within it and does not have its own interface.
For example, if a button control is inside the update panel and it is clicked, only the controls within the update panel will be affected, the controls on the other parts of the page will not be affected.
The UpdateProgress Control
The UpdateProgress control provides a sort of feedback on the browser while one or more update panel controls are being updated. It provides a visual acknowledgement like "Loading page...", indicating the work is in progress.
The Timer Control
The timer control is used to initiate the post back automatically. This could be done in two ways :
(1) Setting the Triggers property of the UpdatePanel control:
(2) Placing a timer control directly inside the UpdatePanel to act as a child control trigger. A single timer can be the trigger for multiple UpdatePanels.
