本文实例为大家分享了UGUI轮播图组件实现的具体代码，供大家参考，具体内容如下

要用到，于是就自已做了一个，自认为封装上还是OK的，开发于unity5.1.2。

支持自动轮播、手势切换、代码调用切换，支持水平和竖直两个方向以及正负方向轮播，轮播索引改变有回调可以用，也可以获取到当前处于正中的子元素。

要注意的是，向轮播列表中加入新元素不能直接setparent，要调用该组件的AddChild方法

下面是鄙人的代码：

/// 主要关注属性、事件及函数：/// public int CurrentIndex;/// public Action<int> OnIndexChange;/// public virtual void MoveToIndex(int ind);/// public virtual void AddChild(RectTransform t);/// by yangxunusing UnityEngine;using System.Collections;using System.Collections.Generic;using UnityEngine.UI;using UnityEngine.EventSystems;using System;/// <summary>/// 轮播图组件/// </summary>[RequireComponent(typeof(RectTransform)), ExecuteInEditMode]public class Carousel : UIBehaviour, IEventSystemHandler, IBeginDragHandler, IInitializePotentialDragHandler, IDragHandler, IEndDragHandler, ICanvasElement { /// <summary> /// 子物体size /// </summary> public Vector2 CellSize; /// <summary> /// 子物体间隔 /// </summary> public Vector2 Spacing; /// <summary> /// 方向 /// </summary> public Axis MoveAxis; /// <summary> /// Tween时的步数 /// </summary> public int TweenStepCount = 10; /// <summary> /// 自动轮播 /// </summary> public bool AutoLoop = false; /// <summary> /// 轮播间隔 /// </summary> public float LoopSpace = 1; /// <summary> /// 轮播方向--1为向左移动，-1为向右移动 /// </summary> public int LoopDir = 1; /// <summary> /// 可否拖动 /// </summary> public bool Drag = true; /// <summary> /// 位于正中的子元素变化的事件,参数为index /// </summary> public Action<int> OnIndexChange; /// <summary> /// 当前处于正中的元素 /// </summary> public int CurrentIndex { get { return m_index; } } private bool m_Dragging = false; private bool m_IsNormalizing = false; private Vector2 m_CurrentPos; private int m_currentStep = 0; private RectTransform viewRectTran; private Vector2 m_PrePos; private int m_index = 0,m_preIndex = 0; private RectTransform header; private bool contentCheckCache = true; private float currTimeDelta = 0; private float viewRectXMin { get{ Vector3[] v = new Vector3[4]; viewRectTran.GetWorldCorners(v); return v[0].x; } } private float viewRectXMax { get { Vector3[] v = new Vector3[4]; viewRectTran.GetWorldCorners(v); return v[3].x; } } private float viewRectYMin { get { Vector3[] v = new Vector3[4]; viewRectTran.GetWorldCorners(v); return v[0].y; } } private float viewRectYMax { get { Vector3[] v = new Vector3[4]; viewRectTran.GetWorldCorners(v); return v[2].y; } } public int CellCount { get { return transform.childCount; } } protected override void Awake() { base.Awake(); viewRectTran = GetComponent<RectTransform>(); header = GetChild(viewRectTran, 0); } public void resizeChildren() { //init child size and pos Vector2 delta; if (MoveAxis == Axis.Horizontal) { delta = new Vector2(CellSize.x + Spacing.x, 0); } else { delta = new Vector2(0, CellSize.y + Spacing.y); } for (int i = 0; i < CellCount; i++) { var t = GetChild(viewRectTran, i); if (t) { t.localPosition = delta * i; t.sizeDelta = CellSize; } } m_IsNormalizing = false; m_CurrentPos = Vector2.zero; m_currentStep = 0; } /// <summary> /// 加子物体到当前列表的最后面 /// </summary> /// <param name="t"></param> public virtual void AddChild(RectTransform t) { if (t!=null) { t.SetParent(viewRectTran, false); t.SetAsLastSibling(); Vector2 delta; if (MoveAxis == Axis.Horizontal) { delta = new Vector2(CellSize.x + Spacing.x, 0); } else { delta = new Vector2(0, CellSize.y + Spacing.y); } if (CellCount == 0) { t.localPosition = Vector3.zero; header = t; } else { t.localPosition = delta + (Vector2)GetChild(viewRectTran,CellCount-1).localPosition; } } } protected override void OnEnable() { base.OnEnable(); resizeChildren(); return; if (Application.isPlaying) { if (ContentIsLongerThanRect()) { int s; do { s = GetBoundaryState(); LoopCell(s); } while (s != 0); } } } protected virtual void Update() { if (ContentIsLongerThanRect()) { //实现在必要时loop子元素 if (Application.isPlaying) { int s = GetBoundaryState(); LoopCell(s); } //缓动回指定位置 if (m_IsNormalizing && EnsureListCanAdjust()) { if (m_currentStep == TweenStepCount) { m_IsNormalizing = false; m_currentStep = 0; m_CurrentPos = Vector2.zero; return; } Vector2 delta = m_CurrentPos/TweenStepCount; m_currentStep++; TweenToCorrect(-delta); } //自动loop if (AutoLoop && !m_IsNormalizing && EnsureListCanAdjust()) { currTimeDelta += Time.deltaTime; if (currTimeDelta>LoopSpace) { currTimeDelta = 0; MoveToIndex(m_index + LoopDir); } } //检测index是否变化 if (MoveAxis == Axis.Horizontal) { m_index = (int)(header.localPosition.x / (CellSize.x + Spacing.x-1)); } else { m_index = (int)(header.localPosition.y / (CellSize.y + Spacing.y-1)); } if (m_index<=0) { m_index = Mathf.Abs(m_index); } else { m_index = CellCount - m_index; } if (m_index != m_preIndex) { if (OnIndexChange != null) { OnIndexChange(m_index); } } m_preIndex = m_index; } } public virtual void OnBeginDrag(PointerEventData eventData) { if (!Drag || !contentCheckCache) { return; } Vector2 vector; if (((eventData.button == PointerEventData.InputButton.Left) && this.IsActive()) && RectTransformUtility.ScreenPointToLocalPointInRectangle(this.viewRectTran, eventData.position, eventData.pressEventCamera, out vector)) { this.m_Dragging = true; m_PrePos = vector; } } public virtual void OnInitializePotentialDrag(PointerEventData eventData) { if (!Drag) { return; } return; } public virtual void OnDrag(PointerEventData eventData) { if (!Drag || !contentCheckCache) { return; } Vector2 vector; if (((eventData.button == PointerEventData.InputButton.Left) && this.IsActive()) && RectTransformUtility.ScreenPointToLocalPointInRectangle(this.viewRectTran, eventData.position, eventData.pressEventCamera, out vector)) { m_IsNormalizing = false; m_CurrentPos = Vector2.zero; m_currentStep = 0; Vector2 vector2 = vector - this.m_PrePos; Vector2 vec = CalculateOffset(vector2); this.SetContentPosition(vec); m_PrePos = vector; } } /// <summary> /// 移动到指定索引 /// </summary> /// <param name="ind"></param> public virtual void MoveToIndex(int ind) { if (m_IsNormalizing) { return; } //Debug.LogFormat("{0}->{1}",m_index,ind); if (ind == m_index) { return; } this.m_IsNormalizing = true; Vector2 offset; if (MoveAxis == Axis.Horizontal) { offset = new Vector2(CellSize.x + Spacing.x, 0); } else { offset = new Vector2(0, CellSize.y + Spacing.y); } var delta = CalcCorrectDeltaPos(); int vindex = m_index; m_CurrentPos = delta + offset * (ind - vindex); //m_CurrentPos = -(Vector2)header.localPosition + offset * (ind - m_index); m_currentStep = 0; } private Vector2 CalculateOffset(Vector2 delta) { if (MoveAxis == Axis.Horizontal) { delta.y = 0; } else { delta.x = 0; } return delta; } private void SetContentPosition(Vector2 position) { foreach (RectTransform i in viewRectTran) { i.localPosition += (Vector3)position; } return; } public virtual void OnEndDrag(PointerEventData eventData) { if (!Drag || !contentCheckCache) { return; } this.m_Dragging = false; this.m_IsNormalizing = true; m_CurrentPos = CalcCorrectDeltaPos(); m_currentStep = 0; } public virtual void Rebuild(CanvasUpdate executing) { return; } /// <summary> /// List是否处于可自由调整状态 /// </summary> /// <returns></returns> public virtual bool EnsureListCanAdjust() { return !m_Dragging && ContentIsLongerThanRect(); } /// <summary> /// 内容是否比显示范围大 /// </summary> /// <returns></returns> public virtual bool ContentIsLongerThanRect() { float contentLen; float rectLen; if (MoveAxis == Axis.Horizontal) { contentLen = CellCount*(CellSize.x + Spacing.x) - Spacing.x; rectLen = viewRectTran.rect.xMax - viewRectTran.rect.xMin; } else { contentLen = CellCount * (CellSize.y + Spacing.y) - Spacing.y; rectLen = viewRectTran.rect.yMax - viewRectTran.rect.yMin; } contentCheckCache = contentLen > rectLen; return contentCheckCache; } /// <summary> /// 检测边界情况，分为0未触界，-1左(下)触界，1右(上)触界 /// </summary> /// <returns></returns> public virtual int GetBoundaryState() { RectTransform left; RectTransform right; left = GetChild(viewRectTran, 0); right = GetChild(viewRectTran, CellCount - 1); Vector3[] l = new Vector3[4]; left.GetWorldCorners(l); Vector3[] r = new Vector3[4]; right.GetWorldCorners(r); if (MoveAxis == Axis.Horizontal) { if (l[0].x>=viewRectXMin) { return -1; } else if (r[3].x < viewRectXMax) { return 1; } } else { if (l[0].y >= viewRectYMin) { return -1; } else if (r[1].y < viewRectYMax) { return 1; } } return 0; } /// <summary> /// Loop列表，分为-1把最右(上)边一个移到最左(下)边，1把最左(下)边一个移到最右(上)边 /// </summary> /// <param name="dir"></param> protected virtual void LoopCell(int dir) { if (dir == 0) { return; } RectTransform MoveCell; RectTransform Tarborder; Vector2 TarPos; if (dir == 1) { MoveCell = GetChild(viewRectTran, 0); Tarborder = GetChild(viewRectTran, CellCount - 1); MoveCell.SetSiblingIndex(CellCount-1); } else { Tarborder = GetChild(viewRectTran, 0); MoveCell = GetChild(viewRectTran, CellCount - 1); MoveCell.SetSiblingIndex(0); } if (MoveAxis == Axis.Horizontal) { TarPos = Tarborder.localPosition + new Vector3((CellSize.x + Spacing.x) * dir, 0,0); } else { TarPos = (Vector2)Tarborder.localPosition + new Vector2(0, (CellSize.y + Spacing.y) * dir); } MoveCell.localPosition = TarPos; } /// <summary> /// 计算一个最近的正确位置 /// </summary> /// <returns></returns> public virtual Vector2 CalcCorrectDeltaPos() { Vector2 delta = Vector2.zero; float distance = float.MaxValue; foreach (RectTransform i in viewRectTran) { var td = Mathf.Abs(i.localPosition.x) + Mathf.Abs(i.localPosition.y); if (td<=distance) { distance = td; delta = i.localPosition; } else { break; } } return delta; } /// <summary> /// 移动指定增量 /// </summary> protected virtual void TweenToCorrect(Vector2 delta) { foreach (RectTransform i in viewRectTran) { i.localPosition += (Vector3)delta; } } public enum Axis { Horizontal, Vertical } private static RectTransform GetChild(RectTransform parent, int index) { if (parent == null||index>=parent.childCount) { return null; } return parent.GetChild(index) as RectTransform; }}

用法和ugui的scrollrect组件是差不多的，因为本来在drag事件上有所借鉴
例图如下：

另外，它不会像ugui的几个布局组件一样自动去改变子元素的大小为cellsize，cellsize只是虚拟的子元素容器大小，这个要注意下。

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。