EditorGUILayout.ObjectField for Array

I've seen this code, might be helpful if someone end up here as I did (even after 4 years)

https://gist.github.com/bzgeb/3800350

 using UnityEngine;
 using System.Collections;
 
 using UnityEditor;
 
 [CustomEditor (typeof(TriggerContainer))]
 public class TriggerContainerEditor : Editor
 {
 
     private SerializedObject obj;
 
     public void OnEnable ()
     {
         obj = new SerializedObject (target);
     }
  
     public override void OnInspectorGUI ()
     {
         DrawDefaultInspector ();
         EditorGUILayout.Space ();
         DropAreaGUI ();
     }
  
     public void DropAreaGUI ()
     {
         Event evt = Event.current;
         Rect drop_area = GUILayoutUtility.GetRect (0.0f, 50.0f, GUILayout.ExpandWidth (true));
         GUI.Box (drop_area, "Add Trigger");
      
         switch (evt.type) {
         case EventType.DragUpdated:
         case EventType.DragPerform:
             if (!drop_area.Contains (evt.mousePosition))
                 return;
              
             DragAndDrop.visualMode = DragAndDropVisualMode.Copy;
          
             if (evt.type == EventType.DragPerform) {
                 DragAndDrop.AcceptDrag ();
              
                 foreach (Object dragged_object in DragAndDrop.objectReferences) {
                     // Do On Drag Stuff here
                 }
             }
             break;
         }
     }
 }