Hi Luis,
We have prepared the sample based on your requirement. In this sample we have binded the command "syncfusion:TabControlCommands.CloseCurrentTabItem" with button in user control. Using this command you can able to close the Tab.
Generally, closing the tab will hide move the item to hidden. Due to this, the Items collection is not changed after removing the Tab. So we have removed the closed item from the collection in CloseButtonClick event. Now, using Items Collection you can get the number of items currently open.
Please refer to the attached sample for your reference
Regards,
Gokul T
Attachment:
WpfApp1_1790fe94.zip