When I have a button to add bunches of items simultaneously to a public list, the list is extended will class of Null but not exactly what I am trying to add. I have to click the button again and again so that the Null would be replaced by the actual item. Also, it is added pages by pages when the list is folded. In version 2.1.10
So this is code for the button and the class and the list containing the class.
After I click the button. This is what I get.
Because I have 42 items, so after I click 42 times, this is what I get, and this is what I expect to have after one click: