我无法从其他类访问GUI（lambda表达式）中使用的变量

I'm making a gui application using javafx that takes input from user and then computes that data in other class. I've tried making an object and accessing it but can't get it to work. I've googled and tried a lot of things like using abstract method but can't get it to work. please tell how can i access the variables( like ID,Party,VoterAge) from controller class or any other classI'm making a gui application using javafx that