In May 2006 Scott Mitchell wrote two articles that showed users how to add a column of checkboxes to a GridView with the ability
for users to check or uncheck all checkboxes in the column with a single click of the mouse. The first article, Checking All CheckBoxes in a GridView, showed how to
add “Check All” and “Uncheck All” buttons to the page above the GridView that, when clicked, checked or unchecked all of the
checkboxes. The second article, Checking All
CheckBoxes in a GridView Using Client-Side Script and a Check All CheckBox, detailed how to add a checkbox to the checkbox column
in the grid’s header row that would check or uncheck all checkboxes in the column. Both articles showed how to implement such
functionality on the client-side, thereby removing the need for a postback.
The JavaScript presented in these two previous articles still works, but the techniques used are a bit antiquated and hamfisted
given the advances made in JavaScript programming over the past few years. For instance, the script presented in the previous articles
uses server-side code in the GridView’s DataBound event handler to assign a client-side onclick event handler to each
checkbox. While this works, it violates the tenets of unobtrusive JavaScript, which is a design guideline for JavaScript programming that encourages a clean
separation of functionality from presentation. (Ideally, event handlers for HTML elements are defined in script.) Also, the quantity
of JavaScript used in the two previous articles is quite hefty compared to the amount of code that would be needed using modern
JavaScript libraries like jQuery.
This ASP.NET tutorial presents updated JavaScript for checking and unchecking all checkboxes within a GridView.
The two examples from the previous articles – checking/unchecking all checkboxes using a button and checking/unchecking all checkboxes
using a checkbox in the header row – are reimplemented here using jQuery and unobtrusive JavaScript techniques. You can read the entire article, Checking All Checkboxes in a GridView Using jQuery here.