Disable dropdown in power apps

Welcome to my very first blog post, thanks for taking time to read my post.

In this post, I’m explaining how to disable a dropdown based on the item selected in the gallery.
I have a gallery which has CDS users.  And a dropdown with Yes or No options.

The below formula explains, Whenever I select the user whose name is “Powerqueryonline”, it should disable the dropdown.

I have added the below formula on “Display Mode” property of the dropdown.

If(

    Gallery3.Selected.’Full Name’ = “Powerqueryonline”,

    DisplayMode.Disabled,

    DisplayMode.Edit

)