How To Use One page Function in Other Page

Here is an example:

Class obj = new Class();
obj.methodCall();

Why don't you create a common class, having all methods common placed there. Now on which page you want the method create an object of the class and access the method.

public class Class1
{

    public void  display()
    {
        Console.WriteLine("Hello Guys");
    }
}

public class Class2
{
    Class1 obj = new Class1();
    public void get()
    {
        obj.display();
    }
    static void main()
    {
        Class1 ooo = new Class1();
        ooo.display();
    }
}

//here i have called the object of the class twice and invoked the function which is public