How can a non-static class call another non-static class's method?

Question

I have 2 classes both non-static. I need to access a method on one class to return an object for processing. But since both classes is non-static, I cant just call the metho

Answer 1

In order for any code in a static or a non-static class to call a non-static method, the caller must have a reference to the object on which the call is made.

In your case, Bar's MethodCaller must have a reference to Foo. You could pass it in a constructor of Bar or in any other way you like:

class Foo
{
    Bar b1 = new Bar(this);

    public object MethodToCall(){ /*Method body here*/ }
}

Class Bar
{
    private readonly Foo foo;

    public Bar(Foo foo) {
        // Save a reference to Foo so that we could use it later
        this.foo = foo;
    }

    public void MethodCaller()
    {
        // Now that we have a reference to Foo, we can use it to make a call
        foo.MethodToCall();
    }
}