本文所实现的UGUI效果需求如下：
- 支持不用Mask遮罩无限循环加载
- 支持ObjectPool动态加载
- 支持无限不规则子物体动态加载
- 支持拖动并点击和拖拽
- 支持拖动并拖拽
- 支持ScrollRect拖动自动吸附功能(拖动是否超过一半自动进退)
要实现以上效果，我从网上搜索得到部分解决方案链接，但不是完全满足想要的效果，就自己继续改造优化和添加想要的效果，本文最后会附带上完整Demo下载链接。
- 缩放循环展示卡牌效果
- 缩放循环展示卡牌效果
- 大量数据无卡顿动态加载，并且支持拖拽、点击和吸附功能
- 大量数据循固定Item复用
- 无限无遮罩动态加载
- 有遮罩无卡顿加载 思路：并没有使用UGUI的ScrollRect组件，摆放几张卡片，通过移动和缩放来实现
using UnityEngine;
using System.Collections;
using System.Collections.Generic;
using UnityEngine.UI;
public class EnhancelScrollView : MonoBehaviour
{
// 缩放曲线
public AnimationCurve scaleCurve;
// 位移曲线
public AnimationCurve positionCurve;
// 位移系数
public float posCurveFactor = 500.0f;
// y轴坐标固定值(所有的item的y坐标一致)
public float yPositionValue = 46.0f;
// 添加到EnhanceScrollView的目标对象
public List<EnhanceItem> scrollViewItems;
// 目标对象Widget脚本，用于depth排序
private List<Image> imageTargets;
// 当前处于中间的item
private EnhanceItem centerItem;
private EnhanceItem preCenterItem;
// 当前出移动中，不能进行点击切换
private bool canChangeItem = true;
// 计算差值系数
public float dFactor = 0.2f;
// 点击目标移动的横向目标值
private float[] moveHorizontalValues;
// 对象之间的差值数组(根据差值系数算出)
private float[] dHorizontalValues;
// 横向变量值
public float horizontalValue = 0.0f;
// 目标值
public float horizontalTargetValue = 0.1f;
// 移动动画参数
private float originHorizontalValue = 0.1f;
public float duration = 0.2f;
private float currentDuration = 0.0f;
private static EnhancelScrollView instance;
public static EnhancelScrollView GetInstance()
{
return instance;
}
void Awake()
{
instance = this;
}
void Start()
{
if((scrollViewItems.Count % 2) == 0)
{
Debug.LogError("item count is invaild,please set odd count! just support odd count.");
}
if(moveHorizontalValues == null)
moveHorizontalValues = new float[scrollViewItems.Count];
if(dHorizontalValues == null)
dHorizontalValues = new float[scrollViewItems.Count];
if (imageTargets == null)
imageTargets = new List<Image>();
int centerIndex = scrollViewItems.Count / 2;
for (int i = 0; i < scrollViewItems.Count;i++ )
{
scrollViewItems[i].scrollViewItemIndex = i;
Image tempImage = scrollViewItems[i].gameObject.GetComponent<Image>();
imageTargets.Add(tempImage);
dHorizontalValues[i] = dFactor * (centerIndex - i);
dHorizontalValues[centerIndex] = 0.0f;
moveHorizontalValues[i] = 0.5f - dHorizontalValues[i];
scrollViewItems[i].SetSelectColor(false);
}
centerItem = scrollViewItems[centerIndex];
canChangeItem = true;
}
public void UpdateEnhanceScrollView(float fValue)
{
for (int i = 0; i < scrollViewItems.Count; i++)
{
EnhanceItem itemScript = scrollViewItems[i];
float xValue = GetXPosValue(fValue, dHorizontalValues[itemScript.scrollViewItemIndex]);
float scaleValue = GetScaleValue(fValue, dHorizontalValues[itemScript.scrollViewItemIndex]);
itemScript.UpdateScrollViewItems(xValue, yPositionValue, scaleValue);
}
}
void Update()
{
currentDuration += Time.deltaTime;
if (currentDuration > duration)
{
// 更新完毕设置选中item的对象即可
currentDuration = duration;
if (centerItem != null)
centerItem.SetSelectColor(true);
if (preCenterItem != null)
preCenterItem.SetSelectColor(false);
canChangeItem = true;
}
SortDepth();
float percent = currentDuration / duration;
horizontalValue = Mathf.Lerp(originHorizontalValue, horizontalTargetValue, percent);
UpdateEnhanceScrollView(horizontalValue);
}
/// <summary>
/// 缩放曲线模拟当前缩放值
/// </summary>
private float GetScaleValue(float sliderValue, float added)
{
float scaleValue = scaleCurve.Evaluate(sliderValue + added);
return scaleValue;
}
/// <summary>
/// 位置曲线模拟当前x轴位置
/// </summary>
private float GetXPosValue(float sliderValue, float added)
{
float evaluateValue = positionCurve.Evaluate(sliderValue + added) * posCurveFactor;
return evaluateValue;
}
public void SortDepth()
{
imageTargets.Sort(new CompareDepthMethod());
for (int i = 0; i < imageTargets.Count; i++)
imageTargets[i].transform.SetSiblingIndex(i);
}
/// <summary>
/// 用于层级对比接口
/// </summary>
public class CompareDepthMethod : IComparer<Image>
{
public int Compare(Image left, Image right)
{
if (left.transform.localScale.x > right.transform.localScale.x)
return 1;
else if (left.transform.localScale.x < right.transform.localScale.x)
return -1;
else
return 0;
}
}
/// <summary>
/// 获得当前要移动到中心的Item需要移动的factor间隔数
/// </summary>
private int GetMoveCurveFactorCount(float targetXPos)
{
int centerIndex = scrollViewItems.Count / 2;
for (int i = 0; i < scrollViewItems.Count;i++ )
{
float factor = (0.5f - dFactor * (centerIndex - i));
float tempPosX = positionCurve.Evaluate(factor) * posCurveFactor;
if (Mathf.Abs(targetXPos - tempPosX) < 0.01f)
return Mathf.Abs(i - centerIndex);
}
return -1;
}
/// <summary>
/// 设置横向轴参数，根据缩放曲线和位移曲线更新缩放和位置
/// </summary>
public void SetHorizontalTargetItemIndex(int itemIndex)
{
if (!canChangeItem)
return;
EnhanceItem item = scrollViewItems[itemIndex];
if (centerItem == item)
return;
canChangeItem = false;
preCenterItem = centerItem;
centerItem = item;
// 判断点击的是左侧还是右侧计算ScrollView中心需要移动的value
float centerXValue = positionCurve.Evaluate(0.5f) * posCurveFactor;
bool isRight = false;
if (item.transform.localPosition.x > centerXValue)
isRight = true;
// 差值,计算横向值
int moveIndexCount = GetMoveCurveFactorCount(item.transform.localPosition.x);
if (moveIndexCount == -1)
{
moveIndexCount = 1;
}
float dvalue = 0.0f;
if (isRight)
dvalue = -dFactor * moveIndexCount;
else
dvalue = dFactor * moveIndexCount;
// 更改target数值，平滑移动
horizontalTargetValue += dvalue;
currentDuration = 0.0f;
originHorizontalValue = horizontalValue;
}
/// <summary>
/// 向右选择角色按钮
/// </summary>
public void OnBtnRightClick()
{
if (!canChangeItem)
return;
int targetIndex = centerItem.scrollViewItemIndex + 1;
if (targetIndex > scrollViewItems.Count - 1)
targetIndex = 0;
SetHorizontalTargetItemIndex(targetIndex);
}
/// <summary>
/// 向左选择按钮
/// </summary>
public void OnBtnLeftClick()
{
if (!canChangeItem)
return;
int targetIndex = centerItem.scrollViewItemIndex - 1;
if (targetIndex < 0)
targetIndex = scrollViewItems.Count - 1;
SetHorizontalTargetItemIndex(targetIndex);
}
}
using UnityEngine;
using System.Collections;
using UnityEngine.UI;
public class EnhanceItem : MonoBehaviour {
// 在ScrollViewitem中的索引
// 定位当前的位置和缩放
public int scrollViewItemIndex = 0;
public bool inRightArea = false;
private Vector3 targetPos = Vector3.one;
private Vector3 targetScale = Vector3.one;
private Transform mTrs;
private Image mImage;
void Awake()
{
mTrs = this.transform;
mImage = this.GetComponent<Image>();
}
void Start()
{
this.gameObject.GetComponent<Button>().onClick.AddListener(delegate () { OnClickScrollViewItem(); });
}
// 当点击Item，将该item移动到中间位置
private void OnClickScrollViewItem()
{
EnhancelScrollView.GetInstance().SetHorizontalTargetItemIndex(scrollViewItemIndex);
}
/// <summary>
/// 更新该Item的缩放和位移
/// </summary>
public void UpdateScrollViewItems(float xValue, float yValue, float scaleValue)
{
targetPos.x = xValue;
targetPos.y = yValue;
targetScale.x = targetScale.y = scaleValue;
mTrs.localPosition = targetPos;
mTrs.localScale = targetScale;
}
public void SetSelectColor(bool isCenter)
{
if (mImage == null)
mImage = this.GetComponent<Image>();
if (isCenter)
mImage.color = Color.white;
else
mImage.color = Color.gray;
}
}
- 有遮罩无卡顿加载 思路：协程加载，先加载屏幕显示的数量，然后返回一帧在继续加载，防止出现数量太大卡顿的现象。
while (CardsList.Count > roleInfo.Count)
{
DestroyImmediate(CardsList[0].gameObject);
CardsList.RemoveAt(0);
}
StartCoroutine(createRoleCards());
private IEnumerator createRoleCards()
{
List<CLocalCharInfo> charInfos = new List<CLocalCharInfo>();
charInfos.AddRange(roleInfo);
int index = 0;
for (int i = 0; i < charInfos.Count; i++)
{
_createRoleCard(charInfos[i], index++);
if (index % 10 == 0)
yield return null;
}
}
private void _createRoleCard(CLocalCharInfo roleInfo, int index)
{
CUIPlayedCharCardWidget charCardWidget = null;
if (CardsList.Count > index)
{
charCardWidget = CardsList[index];
}
else
{
var obj = Instantiate(Resources.Load<GameObject>("Prefab/RoleCard")) as GameObject;
if (obj == null)
{
UnityEngine.Debug.LogError("有误");
return;
}
obj.name = roleInfo.Name;
charCardWidget = obj.GetComponent<CUIPlayedCharCardWidget>();
if (charCardWidget == null)
{
UnityEngine.Debug.LogError("有误");
return;
}
obj.transform.parent = Obj_ScrollViewContent.transform;
obj.transform.localScale = Vector3.one;
CardsList.Add(charCardWidget);
}
CUIPlayedCharCardWidget.CUIContent uiContent = new CUIPlayedCharCardWidget.CUIContent();
uiContent.RoleInfo = roleInfo;
uiContent.ScrollRectObj = m_ScrollRect;
uiContent.FixGridRect = m_FixGrid;
charCardWidget.InitContent(uiContent);
}
- 支持ScrollRect拖拽或点击 思路：在卡片的Image上添加一个继承了IBeginDragHandler,IGradHandler,IEndDragHandler的脚本，重写接口里面的Drag事件方法。
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;
namespace Mga
{
[RequireComponent(typeof(Image))]
public class CPlayedCardOnDrag : MonoBehaviour, IBeginDragHandler, IDragHandler, IEndDragHandler
{
public bool dragOnSurfaces = true;
public ScrollRect m_ScrollRect = null;
public CFixGridRect m_FixGridRect = null;
private GameObject m_DraggingCard;
private RectTransform m_DraggingPlane;
public bool isVertical = false;
private bool isSelf = false;
private System.Action m_OnBeginDragCallBack = null;
private System.Action m_OnEndDragCallBack = null;
private System.Action m_OnBeginScroll = null;
private System.Action m_OnEndScroll = null;
public void Init(CLocalCharInfo roleInfo, System.Action beginCallBack = null, System.Action endCallBack = null, System.Action beginScroll = null, System.Action endScroll = null)
{
m_OnBeginDragCallBack = beginCallBack;
m_OnEndDragCallBack = endCallBack;
m_OnBeginScroll = beginScroll;
m_OnEndScroll = endScroll;
}
public void OnBeginDrag(PointerEventData eventData)
{
Vector2 touchDeltaPosition = Vector2.zero;
#if UNITY_EDITOR
float delta_x = Input.GetAxis("Mouse X");
float delta_y = Input.GetAxis("Mouse Y");
touchDeltaPosition = new Vector2(delta_x, delta_y);
#elif UNITY_ANDROID || UNITY_IPHONE
touchDeltaPosition = Input.GetTouch(0).deltaPosition;
#endif
if (isVertical)
{
if (Mathf.Abs(touchDeltaPosition.x) > Mathf.Abs(touchDeltaPosition.y))
{
isSelf = true;
var canvas = FindInParents<Canvas>(gameObject);
if (canvas == null)
return;
m_DraggingCard = createCard();
m_DraggingCard.transform.SetAsLastSibling();
m_DraggingCard.AddComponent<CIgnoreRayCast>();
if (dragOnSurfaces)
m_DraggingPlane = transform as RectTransform;
else
m_DraggingPlane = canvas.transform as RectTransform;
SetDraggedPosition(eventData);
if (m_OnBeginDragCallBack != null)
{
m_OnBeginDragCallBack();
}
}
else
{
isSelf = false;
if (m_ScrollRect != null)
m_ScrollRect.OnBeginDrag(eventData);
}
}
else
{
if (Mathf.Abs(touchDeltaPosition.x) < Mathf.Abs(touchDeltaPosition.y))
{
isSelf = true;
var canvas = FindInParents<Canvas>(gameObject);
if (canvas == null)
return;
m_DraggingCard = createCard();
m_DraggingCard.transform.SetAsLastSibling();
m_DraggingCard.AddComponent<CIgnoreRayCast>();
if (dragOnSurfaces)
m_DraggingPlane = transform as RectTransform;
else
m_DraggingPlane = canvas.transform as RectTransform;
SetDraggedPosition(eventData);
if (m_OnBeginDragCallBack != null)
{
m_OnBeginDragCallBack();
}
}
else
{
isSelf = false;
if (m_ScrollRect != null)
m_ScrollRect.OnBeginDrag(eventData);
}
}
if (m_OnBeginScroll != null)
m_OnBeginScroll();
}
public void OnDrag(PointerEventData data)
{
if (isSelf)
{
if (m_DraggingCard != null)
{
SetDraggedPosition(data);
}
}
else
{
if (m_ScrollRect != null)
m_ScrollRect.OnDrag(data);
}
}
private void SetDraggedPosition(PointerEventData data)
{
if (dragOnSurfaces && data.pointerEnter != null && data.pointerEnter.transform as RectTransform != null)
m_DraggingPlane = data.pointerEnter.transform as RectTransform;
var rt = m_DraggingCard.GetComponent<RectTransform>();
Vector3 globalMousePos;
if (RectTransformUtility.ScreenPointToWorldPointInRectangle(m_DraggingPlane, data.position, data.pressEventCamera, out globalMousePos))
{
rt.position = globalMousePos;
rt.rotation = m_DraggingPlane.rotation;
}
}
private GameObject createCard()
{
CUIPlayedCharCardWidget charCardWidget = null;
m_DraggingCard = Instantiate(Resources.Load<GameObject>("Prefab/RoleCard") as GameObject);
if (m_DraggingCard == null)
{
return null;
}
charCardWidget = m_DraggingCard.GetComponent<CUIPlayedCharCardWidget>();
if (charCardWidget == null)
{
return null;
}
CUIPlayedCharCardWidget.CUIContent uiContent = new CUIPlayedCharCardWidget.CUIContent();
charCardWidget.InitContent(uiContent);
return m_DraggingCard;
}
public void OnEndDrag(PointerEventData eventData)
{
if (isSelf)
{
if (m_DraggingCard != null)
{
Destroy(m_DraggingCard);
if (m_OnEndDragCallBack != null)
{
m_OnEndDragCallBack();
}
}
}
else
{
if (m_ScrollRect != null)
m_ScrollRect.OnEndDrag(eventData);
if (m_FixGridRect != null)
m_FixGridRect.OnEndDrag(eventData);
}
}
static public T FindInParents<T>(GameObject go) where T : Component
{
if (go == null) return null;
var comp = go.GetComponent<T>();
if (comp != null)
return comp;
Transform t = go.transform.parent;
while (t != null && comp == null)
{
comp = t.gameObject.GetComponent<T>();
t = t.parent;
}
return comp;
}
}
}
如果想要实现拖拽到目标位置的检测，还要在目标位置放一个Image并且添加上继承了IDropHandler,IPointerEnterHandler,IPointerExitHanler的组件。
using System.Reflection;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;
using System.Collections;
namespace Mga
{
public class CPlayedCardOnDrop : MonoBehaviour, IDropHandler, IPointerEnterHandler, IPointerExitHandler
{
public Image containerImage;
public Image receivingImage;
private Color normalColor;
public Color highlightColor = Color.yellow;
private int drapAreaIndex = 0;
void Start()
{
drapAreaIndex = System.Convert.ToInt32(this.transform.parent.name);
}
public void OnEnable()
{
if (containerImage != null)
normalColor = containerImage.color;
}
public void OnDrop(PointerEventData data)
{
containerImage.color = normalColor;
if (receivingImage == null)
return;
Sprite dropSprite = GetDropSprite(data);
if (dropSprite != null)
receivingImage.overrideSprite = dropSprite;
}
public void OnPointerEnter(PointerEventData data)
{
if (containerImage == null)
return;
Sprite dropSprite = GetDropSprite(data);
if (dropSprite != null)
containerImage.color = highlightColor;
}
public void OnPointerExit(PointerEventData data)
{
if (containerImage == null)
return;
containerImage.color = normalColor;
}
private Sprite GetDropSprite(PointerEventData data)
{
var originalObj = data.pointerDrag;
if (originalObj == null)
return null;
var srcImage = originalObj.GetComponent<Image>();
if (srcImage == null)
return null;
return srcImage.sprite;
}
}
}
在ScrollRect物体上添加吸附功能组件，工程里面要使用DoTween插件
using System.Collections.Generic;
using DG.Tweening;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;
//TODO:当前只试应横向的ScrollRect，还需要扩展支持纵向
public class CFixGridRect : MonoBehaviour, IEndDragHandler
{
public GameObject content;
public ScrollRect scorllRect;
public float itemWidth;
private RectTransform contentRectTf;
private float formalPosX = 0;
private float currentPosX = 0;
private float halfItemLength = 0;
void Start()
{
if (itemWidth <= 0)
UnityEngine.Debug.LogError("请设置Item的宽度");
halfItemLength = itemWidth / 2;
this.contentRectTf = this.content.GetComponent<RectTransform>();
}
public void OnEndDrag(PointerEventData eventData)
{
this.scorllRect.StopMovement();
Vector2 afterDragPagePos = this.content.transform.localPosition;
currentPosX = afterDragPagePos.x; //当前拖动的位置 负
if (scorllRect.horizontalNormalizedPosition < 0 || scorllRect.horizontalNormalizedPosition > 1)
return;
int count = (int)(Mathf.Abs(currentPosX) / itemWidth);
var targetPos = -(float)(count * itemWidth);
if (((float)(count * itemWidth + halfItemLength)) < Mathf.Abs(currentPosX))
{
targetPos = -(float)((count + 1) * itemWidth);
}
formalPosX = targetPos;
this.contentRectTf.DOLocalMoveX(targetPos, .2f);
}
}
具体DemoGit下载链接
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using System.Collections.Generic;
using DG.Tweening;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;
namespace Mga
{
public enum DragDirection
{
Horizontal,
Vertical,
}
public class CFixGridRectBase : MonoBehaviour, IEndDragHandler
{
public class CUIContent
{
public GameObject ScrollRectContent;
public ScrollRect m_ScorllRect;
public float ItemSize;
public float ItemSpaceLength; //间隙
public float Margin = 0; //顶部边缘间隙
public DragDirection m_DragDirection = DragDirection.Vertical;
}
private RectTransform contentRectTf;
private float halfItemLength = 0;
private CUIContent m_uiContent = null;
private bool m_bWidgetReady = false;
void Start()
{
m_bWidgetReady = true;
_initContent();
}
public void InitContent(CUIContent uiContent)
{
m_uiContent = uiContent;
if (m_bWidgetReady)
_initContent();
}
private void _initContent()
{
if (m_uiContent == null) return;
if (m_uiContent.ItemSize <= 0)
{
UnityEngine.Debug.LogError("请设置Item的宽度");
return;
}
halfItemLength = m_uiContent.ItemSize / 2;
this.contentRectTf = m_uiContent.ScrollRectContent.GetComponent<RectTransform>();
}
public void OnEndDrag(PointerEventData eventData)
{
m_uiContent.m_ScorllRect.StopMovement();
Vector2 afterDragPagePos = m_uiContent.ScrollRectContent.transform.localPosition;
var itemLength = m_uiContent.ItemSize + m_uiContent.ItemSpaceLength;
if (m_uiContent.m_DragDirection == DragDirection.Horizontal)
{
var currentPosX = afterDragPagePos.x; //当前拖动的位置 负
currentPosX -= m_uiContent.Margin;
int count = (int)(Mathf.Abs(currentPosX) / m_uiContent.ItemSize);
if (m_uiContent.m_ScorllRect.horizontalNormalizedPosition <= 0)
{
return;
}
else if (m_uiContent.m_ScorllRect.horizontalNormalizedPosition >= 1) //总数-当前显示的数量
{
return;
}
var targetPosX = -(float)(count * itemLength);
if (((float)(targetPosX + halfItemLength)) < Mathf.Abs(currentPosX))
{
count++;
targetPosX = -(float)(count * itemLength);
}
this.contentRectTf.DOLocalMoveX(targetPosX, .2f);
}
else
{
var currentPosY = afterDragPagePos.y; //当前拖动的位置 正
currentPosY -= m_uiContent.Margin;
int count = (int)(Mathf.Abs(currentPosY) / itemLength);
if (m_uiContent.m_ScorllRect.verticalNormalizedPosition <= 0)
{
return;
}
else if (m_uiContent.m_ScorllRect.verticalNormalizedPosition >= 1) //总数-当前显示的数量
{
return;
}
var targetPosY = (float)(count * itemLength);
if (((float)(targetPosY + halfItemLength)) < Mathf.Abs(currentPosY))
{
count++;
targetPosY = (float)(count * itemLength);
}
this.contentRectTf.DOLocalMoveY(targetPosY, .2f);
}
}
}
}