ButtonDefinition mixed/indeterminate check state

[DRoam]

I can make a button within a context menu appear checked or unchecked using the "Pressed" property:

How can I make a button appear with the "mixed"/"indeterminate" checked state, like this?

Is this possible with a custom add-in command button?

[Rene_Gerlach · Accepted solution]

Did you try to change the "StandardIcon" depending on your three states?

"Pressed" wouldn't help,because it has only two states.

[DRoam]

Hi @Rene_Gerlach, that's a good idea, I didn't think of that -- setting an icon rather than using the pressed/unpressed states. I'll give that a try, I think that should work. Thanks!