Dropdown.cs

using UnityEngine;
using System.Collections;
using UnityEngine.EventSystems;
using UnityEngine.UI;

public class Dropdown : MonoBehaviour, IPointerEnterHandler, IPointerExitHandler
{
    public RectTransform container;
    public bool isOpen;
    public Text mainText;
    public Image image { get { return GetComponent<Image>(); } }


    void Start()
    {
        container = transform.FindChild("Container").GetComponent<RectTransform>();
        isOpen = false;
    }
    public void Update()
    {
        Vector3 scale = container.localScale;
        scale.y = Mathf.Lerp(scale.y, isOpen ? 1 : 0, Time.deltaTime * 10);
        container.localScale = scale;
    }


    public void OnPointerEnter(PointerEventData eventData)
    {
        isOpen = true;
    }

    public void OnPointerExit(PointerEventData eventData)
    {
        isOpen = false;
    }

}