如果在swift中按下NSButton，则创建简单的动作

I am in the process of learning swift. I would like to know how to programmatically call a function if a button is pressed.... I tried this, but the function is executed directly when the programm launches, not when I press the button... Can you please help me to fix this.. Thank you below the full ViewController.swift for this test appI am in the process of learning swift. I would