マウスイベントインタフェース

2つのインタフェースを継承するIPointerDownHandler、IPointerUpHandlerをマウスで押し続け、このクラスを対応するUIに掛けます.

using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;

public class Operation : MonoBehaviour,IPointerDownHandler, IPointerUpHandler
{   
    public  bool pressed = false;
    public void OnPointerDown(PointerEventData eventData)
    {
        pressed = true;
    }

    public void OnPointerUp(PointerEventData eventData)
    {
        pressed = false;
    }
 }   

各UIにおいて、マウスが押し続けるか否かを判定し、それをコンポーネントとして各UIに加えて判定する

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

public class OperationPlaneButton : MonoBehaviour
{

    private Button[] bts;
    private GameObject cfj;
    private bool isDown = false;

    private void Awake()
    {      
        bts = this.GetComponentsInChildren();
        Getbtns();
    }
    // Use this for initialization
    void Start ()
    {
        cfj = GameObject.Find("cfj");     
    }
    void Getbtns()
    {
        foreach (var item in bts)
        {
            item.gameObject.AddComponent();           
        }
    }

    private  void RorateX()
    {
        cfj.transform.Rotate(-5, 0, 0);     
    }


    // Update is called once per frame
    void Update ()
    {    
        foreach (var item in bts)
        {
            isDown = item.gameObject.GetComponent().pressed;      
             if (isDown==true)
              {
                if (item.gameObject.name== "Button")
                {
                    RorateX();
                    print(2);
                }                
              }                  
        }
    }  
}