There are a lot of images to load in my page. I want to improve the performance of the page by scrolling down load. but I don’t know how to get the scroll down events and scroll position of the window in dash, Does anybody can give me some advice? I will be very grateful.
Hi, you can use visdcc.Run_js to write your own javascript event listener. 
here is the example code
https://github.com/jimmybow/visdcc/blob/master/example/Run_js/Add_event_and_callback.py
Thank you very much for your answer, I am trying to write a component, now I will take a closer look at the information you gave me.