As you can specify the dropdownlists(comboboxes) in the CGridView header by a query of “.grid-view thead select”, it’s very easy to apply the custom style to them.
.grid-view thead select {
background:url(canvas-list-nav-item-arrow-.gif) no-repeat center right;
}
There’s no need to use a single line of javascript.
But if you do have to use a script to style the dropdownlists, then you can use ‘afterAjaxUpdate’.