Skip to Main Content
Essential SharePoint
book

Essential SharePoint

by Jeff Webb
May 2005
Beginner content levelBeginner
336 pages
10h 14m
English
O'Reilly Media, Inc.
Content preview from Essential SharePoint

Understanding Event Order

From an event perspective, web part programming is very different from Windows Forms programming. In Windows Forms applications, code runs as long as the form is displayed and responds as events occur. Web part code runs only short bursts—beginning when the request is received by the server and ending shortly after the response is returned to the client browser.

The performance difference between the server and client Sum controls illustrates a basic principle of web part design: avoid unnecessary postbacks. The button web control and submit button trigger postback events by default, but you can also set the AutoPostback property on textbox, list, and checkbox controls to cause postbacks. When a postback event occurs, the browser sends the current state of the page back to the server, which then processes web part events and overridden methods in the order shown in Table 9-2.

Table 9-2. Order of major server events/methods in a web part

Event/method

Use to

OnInit event

Create the web part.

LoadViewState method

Override the web part's base class behavior when reading control properties from the web part's ViewState object.

CreateChildControls method

Add web controls to the Controls collection.

Onload event

Initialize resources used by the web part.

Cached child control events

Process cached events from child controls, such as TextChanged or SelectedIndexChanged.

Postback child control event

Process the event that caused the postback, for example ...

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Start your free trial

You might also like

SharePoint User's Guide

SharePoint User's Guide

Infusion Development Corp. (Infusion Development Corporation)
Beginning SharePoint® 2010: Building Business Solutions with SharePoint

Beginning SharePoint® 2010: Building Business Solutions with SharePoint

Amanda Perran, Shane Perran, Jennifer Mason, Laura Rogers

Publisher Resources

ISBN: 0596008805Errata Page