Eg ExtJS icons as used in the example eplorer
<!-- Styles for icons on treepanel -->
<style type="text/css">
button.collapse-all {
background-image: url(images/collapse-all.gif) !important;
}
button.expand-all {
background-image: url(images/expand-all.gif) !important;
}
</style>
I am using the style in code behind
ext.Button btnExpand = new ext.Button();
btnExpand.Text = "Expand";
btnExpand.IconCls = "expand-all";
btnExpand.Listeners.Click.Handler = tree.ClientID + ".expandAll();";
ext.Button btnCollapse = new ext.Button();
btnCollapse.Text = "Collapse";
btnCollapse.IconCls = "collapse-all";
btnCollapse.Listeners.Click.Handler = tree.ClientID + ".collapseAll();";