Inspector GUI

https://answers.unity.com/questions/814870/why-arent-public-variables-shown-in-the-inspector.html

public variables shown in the Inspector when inheriting

Class used on game object

using UnityEngine;
 using System.Collections;
 using UnityEngine.UI;
 using System;
 
 [Serializable]
public class UIButton : Button
{
    public enum TestEnum { ON, OFF }
 
    public int testInt;
    public TestEnum testEnumVar;
}

Class used to override the inspectorGUI

 using UnityEngine;
 using System.Collections;
 using UnityEditor;
 [CustomEditor(typeof(UIButton))]
public class UIButtonEditor : Editor
{
    public override void OnInspectorGUI()
    {
        base.OnInspectorGUI();
        UIButton t = (UIButton)target;
    }
}