Error 1 A field initializer cannot reference the non-static field, method, or property

Question

 public partial class Form1 : Form
  {
    Class1 class = new Class1(30,a);

    public Form1()
    {

        InitializeComponent();
    }

     public int a = 0;


            


        

Answer 1

Just move the initialization of class1 into a constructor:

class Form1 {
    int a = 0;

    Class1 obj1;

    public Form1() {
        obj1 = new Class1(a);
    }
}