Question

You are implementing an ASP.NET application that uses data-bound GridView controls in multiple
pages. You add JavaScript code to periodically update specific types of data
items in these GridView controls. You need to ensure that the JavaScript code can locate the
HTML elements created for each row in these GridView controls, without needing
to be changed if the controls are moved from one page to another. What should
you do?

A. Replace the GridView control with a ListView control.
B. Set the ClientIDMode attribute to Predictable in the web.config file.
C. Set the ClientIDRowSuffix attribute of each unique GridView control to a different value.
D. Set the @ OutputCache directives VaryByControl attribute to the ID of the GridView control

Answer 1

Using Predictable for everything is not that great. You can find a good article on the whole topic of ClientIDMode here:

http://www.west-wind.com/weblog/posts/2009/Nov/07/ClientIDMode-in-ASPNET-40

In short:

• Add ClientIDMode=”Static” to each Page (or in web.config’s setting)
• Add ClientIDMode=”Predictable” explicitly to each List Control Children in Databound Template
• Override explicitly to Predictable where naming conflicts are a problem and to AutoId for the extreme edge case
• For Control Development leave at default behavior if possible (ie. Inherit from parent)
• Override only when necessary and preferrably on individual subcontrols