Hello Cyril,
Thank you for the feature request. Similar to the feature request to customize icons in the Kendo UI Menu, I am approving this request and setting it as unplanned.
Please use the following CSS to customize the icons in the Kendo UI TreeView:
@import "https://netdna.bootstrapcdn.com/font-awesome/3.2.1/css/font-awesome.css";
.k-icon.k-i-collapse::before {
content: "\\f107";
font-family: FontAwesome;
}
.k-icon.k-i-expand::before {
content: "\\f105";
font-family: FontAwesome;
}
In this StackBlitz example, I have replaced the default Kendo UI TreeView icons with the Font Awesome icons.
Let me know if you have any further questions pertaining to this case.
Regards,
Hetali
Progress Telerik
Love the Telerik and Kendo UI products and believe more people should try them? Invite a fellow developer to become a Progress customer and each of you can get a $50 Amazon gift voucher.