Unity UGUI 按钮呈半圆型滑动的无限列表 可左右镜像排列

   上一篇是实现了按钮可拖拽并自动吸附在屏幕两侧，接着呈半圆分布。之前是道具按钮比较少的情况，道具按钮一多，屏幕空间又局促的情况下，按钮就要适当隐藏了，所以做成一个可以滑动的列表。滑动的轨迹是一个圆形。这个需求还挺有意思的，记录一下代码：

                                          

using DG.Tweening;
using System.Collections;
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.EventSystems;
using UnityEngine.SceneManagement;
using System.Collections.Generic;
namespace ArrowLegend
{
    /// <summary>
    /// 按钮自动吸附和呈半圆分布
    /// </summary>
    public class AutoAdsorptiontoEdge : MonoBehaviour, IBeginDragHandler, IDragHandler,  IEndDragHandler
    {
        private RectTransform rectTransform;
        
        
        public RectTransform SlidingZone;//旋转滑动区域
        public RectTransform Mask;//遮罩区域
        public RectTransform RightMask;//右遮罩区域
        public RectTransform LeftMask;//左遮罩区域
        //public RectTransform RightSlidingZone;//右滑动区域
        //public RectTransform LeftSlidingZone;//左滑动区域
        private CircleSliding circleSliding;
        private Button[] propButtons;
        private Button CenterBtn;
        private bool isRight;
        private float LeftAdsorptiontoX;//吸附到的位置，根据屏幕判断
        private float RightAdsorptiontoX;
        private float UpAdsorptiontoY;//上下位置判断，防止出现按钮到屏幕外的情况
        private float DownAdsorptionY;
        //private List<Button> currentPropBtnList = new List<Button> ();//当前正在展示的按钮
        private int showNum = 4;//展示个数
        
        void Start()
        {
            rectTransform = GetComponent<RectTransform>();
            circleSliding = SlidingZone.GetComponent<CircleSliding>();
            propButtons = circleSliding.PropBtns;
            CenterBtn = circleSliding.CenterPos.GetComponent<Button>();
        }
        public void OnBeginDrag(PointerEventData data)
        {
            if (!new Rect(0, 0, Screen.width,  Screen.height).Contains(Input.mousePosition)) return;
            for (int i = 0; i < propButtons.Length; i++)
            {
             
                propButtons[i].gameObject.SetActive(false);
            }
            Vector3 leftPos;
            RectTransformUtility.ScreenPointToWorldPointInRectangle(rectTransform, new  Vector2(Screen.width/15f, Screen.height/15f), data.enterEventCamera, out leftPos);
            LeftAdsorptiontoX = leftPos.x;
            DownAdsorptionY = leftPos.y;
           
            Vector3 rightPos;
            RectTransformUtility.ScreenPointToWorldPointInRectangle(rectTransform, new  Vector2(Screen.width/15f*14, Screen.height/15f*14), data.enterEventCamera, out rightPos);
            RightAdsorptiontoX = rightPos.x;
            UpAdsorptiontoY = rightPos.y;
        }
        public void OnDrag(PointerEventData data)
        {
            
            Vector3 pos;
            //限定在屏幕内操作
            if (!new Rect(0, 0, Screen.width,  Screen.height).Contains(Input.mousePosition)) return;
           
            if (RectTransformUtility.ScreenPointToWorldPointInRectangle(rectTransform,  data.position, data.enterEventCamera, out pos))
            {
               
                rectTransform.position = pos;
                //for (int i = 0; i < PropButtons.Length; i++)
                //{
                //    PropButtons[i].transform.position = ShopBtn.transform.position;
                //}
            };
          
        }
        public void OnEndDrag(PointerEventData data)
        {
            if (rectTransform.position.y < DownAdsorptionY)
            {
                rectTransform.position = new Vector2(rectTransform.position.x,  DownAdsorptionY);
            }
            else if(rectTransform.position.y > UpAdsorptiontoY)
            {
                rectTransform.position = new Vector2(rectTransform.position.x,  UpAdsorptiontoY);
            }
            //左右镜像
            if (rectTransform.position.x > 0)
            {
                rectTransform.DOMove(new Vector3(RightAdsorptiontoX,  rectTransform.position.y), 0.4f).OnComplete(() =>
               {
                   MoveToRight();
                
               });
            }
            else
            {
                rectTransform.DOMove(new Vector3(LeftAdsorptiontoX,  rectTransform.position.y), 0.4f).OnComplete(() =>
                {
                    MoveToLeft();
                
                });
            }
         
        }
        /// <summary>
        /// 移动到右边
        /// </summary>
        private void MoveToRight()
        {
            //SlidingZone.transform.DOMoveX(1.5f,0);
            //SlidingZone.transform.position = RightSlidingZone.transform.position;
            for (int i = 0; i < propButtons.Length; i++)
            {
                propButtons[i].transform.SetParent(this.transform);
            }
            //Mask.transform.DOMoveX(1.72f, 0).OnComplete(() =>
            Mask.transform.DOMove(RightMask.transform.position,0).OnComplete(()=>
                {
                    for (int i = 0; i < propButtons.Length; i++)
                    {
                        propButtons[i].transform.SetParent(Mask);
                    }
                    circleSliding.IsRight(true);
                });
        }
        /// <summary>
        /// 移动到左边
        /// </summary>
        private void MoveToLeft()
        {
            //SlidingZone.transform.DOMoveX(-1.5f, 0);
            //SlidingZone.transform.position = LeftSlidingZone.transform.position;
            for (int i = 0; i < propButtons.Length; i++)
            {
                propButtons[i].transform.SetParent(this.transform);
            }
            Mask.transform.DOMove(LeftMask.transform.position, 0).OnComplete(() =>
            {
                for (int i = 0; i < propButtons.Length; i++)
                {
                    propButtons[i].transform.SetParent(Mask);
                }
                circleSliding.IsRight(false);
            });
        }
      
    }
}

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


namespace ArrowLegend
{
    /// <summary>
    /// 半圆滑动代码
    /// </summary>
    public class CircleSliding : MonoBehaviour, IBeginDragHandler, IDragHandler, IEndDragHandler
    {


       
        public Transform CenterPos;//中心点位置
        public Button[] PropBtns;//待排列的按钮
        public int SlidingSpeed = 10;//滑动速度
        //public AutoAdsorptiontoEdge autoAdsorptiontoEdge;//自动吸附组件




        private Vector2 previousPos;//先前位置
        private float radius = 0.5f;//半径
        private float currentAngle = 0;//旋转的角度
        public float CurrentAngle
        {
            get { return currentAngle; }
        }
        private int showNum = 4;//展示个数


        private Queue<Button> unShowBtnQueue = new Queue<Button>();//还没展示按钮
        private Stack<Button> leftUpBtnStack = new Stack<Button>();//左上待用按钮栈
        private Stack<Button> leftDownStack = new Stack<Button>();//左下待用按钮栈
       
        public List<Button> currentShowBtnList = new List<Button>();//当前展示的按钮


        private int upIndex = 0;//向上移动了几个
        private int downIndex = 0;//向下移动了几个
        private bool needClear = false;//是否需要清除
        private bool m_IsRight;//是否是右边


        void Start()
        {
            for (int i = 0; i < PropBtns.Length; i++)
            {
                PropBtns[i].transform.position = CenterPos.transform.position + GetPosXYByAngle((180 / (/*PropButtons.Length*/showNum - 1)) * i);
              
                //只展示前面5个，剩下的放在右下方并隐藏备用
                if (i >= showNum)
                {
                    PropBtns[i].transform.position = CenterPos.transform.position + GetPosXYByAngle((180 / (/*PropButtons.Length*/showNum - 1)) * showNum);
                    PropBtns[i].gameObject.SetActive(false);
                    unShowBtnQueue.Enqueue(PropBtns[i]);
                }
                else
                {
                    currentShowBtnList.Add(PropBtns[i]);
                }


            }
        }


        void Update()
        {
            //if (Input.GetKeyDown(KeyCode.Space))
            //{
            //    isRight = true;
            //    //int index = currentShowBtnList.Count;
            //    for (int i = 0; i < currentShowBtnList.Count; i++)
            //    {
            //        //index -= 1;
            //        PropBtns[i].transform.position = CenterPos.transform.position + GetPosXYByAngle(-((180 / (/*PropButtons.Length*/showNum - 1)) * i - currentAngle));
            //    }
            //}
        }


        /// <summary>
        /// 是否吸附在右边
        /// </summary>
        /// <param name="isRight"></param>
        public void IsRight(bool isRight)
        {
            m_IsRight = isRight;
            if (m_IsRight == true)
            {
                for (int i = 0; i < currentShowBtnList.Count; i++)
                {
                    currentShowBtnList[i].gameObject.SetActive(true);
                    currentShowBtnList[i].transform.position = CenterPos.transform.position + GetPosXYByAngle(-((180 / (/*PropButtons.Length*/showNum - 1)) * i - currentAngle));
                }
            }
            else
            {
                for (int i = 0; i < currentShowBtnList.Count; i++)
                {
                    currentShowBtnList[i].gameObject.SetActive(true);
                    currentShowBtnList[i].transform.position = CenterPos.transform.position + GetPosXYByAngle(((180 / (/*PropButtons.Length*/showNum - 1)) * i - currentAngle));
                }
            }
           
        }


        public void OnBeginDrag(PointerEventData eventData)
        {
            previousPos = eventData.position;
           
        }


        public void OnDrag(PointerEventData eventData)
        {
            if(eventData.position.y== previousPos.y)
            {
                return;
            }
            if (eventData.position.y > previousPos.y)
            {
                BtnMove(true);
            }
            else
            {
                BtnMove(false);
            }
            previousPos = eventData.position;
        }


        public void OnEndDrag(PointerEventData eventData)
        {
            
        }


        /// <summary>
        /// 按钮围绕圆心移动
        /// </summary>
        private void BtnMove(bool isUp)
        {
            //向上移动
            if (isUp)
            {
                currentAngle += SlidingSpeed;
                if (currentAngle >= upIndex * 60)
                {
                    //向上移动判断右下栈中是否有数据
                    if (leftDownStack.Count > 0)
                    {
                        currentShowBtnList.Add(leftDownStack.Pop());
                        needClear = true;
                        upIndex += 1;
                    }
                    //是否还有没有展示过的按钮
                    else if(unShowBtnQueue.Count > 0)
                    {
                        currentShowBtnList.Add(unShowBtnQueue.Dequeue());
                        needClear = true;
                        upIndex += 1;
                    }
                    //向上滑动到底
                    else
                    {
                        for (int i = 0; i < currentShowBtnList.Count; i++)
                        {
                            currentShowBtnList[i].gameObject.SetActive(true);
                            if (m_IsRight)
                            {
                                currentShowBtnList[i].transform.position = CenterPos.transform.position + GetPosXYByAngle(-((180 / (/*PropButtons.Length*/showNum - 1)) * i - currentAngle));
                            }
                            else
                            {
                                currentShowBtnList[i].transform.position = CenterPos.transform.position + GetPosXYByAngle((180 / (/*PropButtons.Length*/showNum - 1)) * i - currentAngle);
                            }
                            
                        }
                        currentAngle -= SlidingSpeed;
                        return;
                    }
                }
                //移动超过60度达到清理条件，清理第一个按钮
                if (needClear && currentAngle >= 60)
                {
                    needClear = false;
                    currentShowBtnList[0].transform.position = CenterPos.transform.position + GetPosXYByAngle((180 / (/*PropButtons.Length*/showNum - 1)) * showNum);
                    currentShowBtnList[0].gameObject.SetActive(false);
                    leftUpBtnStack.Push(currentShowBtnList[0]);
                    currentShowBtnList.Remove(currentShowBtnList[0]);
                    currentAngle -= 60;
                    upIndex -= 1;
                }
            }


            else
            {
                currentAngle -= SlidingSpeed;
                if (currentAngle <= downIndex*(-60))
                {
                    if (leftUpBtnStack.Count > 0)
                    {
                        needClear = true;
                        downIndex += 1;
                        Button btn = leftUpBtnStack.Pop();
                        btn.gameObject.SetActive(true);
                        currentShowBtnList = InsertBtnToHead(btn, currentShowBtnList);
                        currentAngle += 60;
                       
                    }
                    else
                    {
                        for (int i = 0; i < currentShowBtnList.Count; i++)
                        {
                            currentShowBtnList[i].gameObject.SetActive(true);
                            if (m_IsRight)
                            {
                                currentShowBtnList[i].transform.position = CenterPos.transform.position + GetPosXYByAngle(-((180 / (/*PropButtons.Length*/showNum - 1)) * i - currentAngle));
                            }
                            else
                            {
                                currentShowBtnList[i].transform.position = CenterPos.transform.position + GetPosXYByAngle((180 / (/*PropButtons.Length*/showNum - 1)) * i - currentAngle);
                            }
                        }
                        currentAngle += SlidingSpeed;
                        return;
                    }
                  
                }
                if (needClear /*&& currentAngle <0*/)
                {
                    needClear = false;
                    currentShowBtnList[currentShowBtnList.Count-1].transform.position = CenterPos.transform.position + GetPosXYByAngle((180 / (/*PropButtons.Length*/showNum - 1)) * showNum);
                    currentShowBtnList[currentShowBtnList.Count - 1].gameObject.SetActive(false);
                    leftDownStack.Push(currentShowBtnList[currentShowBtnList.Count - 1]);
                    currentShowBtnList.Remove(currentShowBtnList[currentShowBtnList.Count - 1]);
                    downIndex -= 1;
                }
            }




            for (int i = 0; i < currentShowBtnList.Count; i++)
            {
                currentShowBtnList[i].gameObject.SetActive(true);
                if (m_IsRight)
                {
                    currentShowBtnList[i].transform.position = CenterPos.transform.position + GetPosXYByAngle(-((180 / (/*PropButtons.Length*/showNum - 1)) * i - currentAngle));
                }
                else
                {
                    currentShowBtnList[i].transform.position = CenterPos.transform.position + GetPosXYByAngle((180 / (/*PropButtons.Length*/showNum - 1)) * i - currentAngle);
                }
            }




        }


        private List<Button> InsertBtnToHead(Button btn,List<Button> btnList)
        {
            List<Button> tempBtnList = new List<Button>();
            tempBtnList.Add(btn);
            for(int i= 0; i < btnList.Count; i++)
            {
                tempBtnList.Add(btnList[i]);
            }
            return tempBtnList;
        }


        /// <summary>
        /// 根据角度拿到相对于圆心的XY坐标
        /// </summary>
        /// <param name="angle"></param>
        /// <returns></returns>
        public Vector3 GetPosXYByAngle(float angle)
        {
            if (angle > 90)
            {
                angle = 180 - angle;
                Vector3 pos = new Vector3();
                pos.x = Mathf.Sin(angle * Mathf.Deg2Rad) * radius;
                pos.y = -Mathf.Cos(angle * Mathf.Deg2Rad) * radius;
                return pos;
            }
            else
            {
                Vector3 pos = new Vector3();
                pos.x = Mathf.Sin(angle * Mathf.Deg2Rad) * radius;


                pos.y = Mathf.Cos(angle * Mathf.Deg2Rad) * radius;
                return pos;
            }


        }
    }
}

由于项目时间比较紧张，很多东西没有抽象出来，等有时间了会考虑做成一个好用的工具。