问题 In my kivy project, I have a button allowing me to generate a matplotlib graph in .png format. Generating this image takes time (around 20 seconds), and I would like to display a pop-up window to warn the user. What i tried : <MyPopup@Popup>: auto_dismiss: False Button: text: 'This could take time, please wait :) ' on_release: root.dismiss() and : ActionButton: text: 'generate graph' on_release: Factory.MyPopup().open() #on_release: root.generate_graph() Unfortunately, if I uncomment the