Hi Ross,
Thank you for using Syncfusion products.
We have created the sample for collapsing the Taskbar Item programmatically. There is a Boolean property called SetIsOpened by setting this property to false by programmatically, you could be able to collapse the Taskbar Item and similarly we can expand the Taskbar Item by setting the property value to True .
Please refer the illustrating sample under the following location.
Please let us know if you have any queries.
Regards,
Sakthi
TaskBar-957218043_b53ea57d.zip