UnityEngine实现滚动例子(ScrollView)

【核心代码】

using UnityEngine;
using System.Collections;
using System.Collections.Generic;

public class SelfScrollView : MonoBehaviour, ISelfScrollView 
{
public SelfScrollDirectionTypeEnum directionTypeEnum = SelfScrollDirectionTypeEnum.Vertical;
public int MaxItemCount;
public SelfScrollItem ScrollItem;
public float YOffset;
public List<object> DataList;
public string Response;

public List<ISelfScrollItem> itemList;

private bool mousePress;
private Vector3 mousePosition;
private Vector3 offsetPosition;

private SelfScrollViewManager selfScrollViewManager;

void Awake()
{
this.AwakeBeforeHandler ();
this.AwakeHandler ();
this.AwakeAfterHandler ();
}

protected virtual void AwakeBeforeHandler() {}
protected virtual void AwakeHandler()
{
if(this.itemList == null) this.itemList = new List<ISelfScrollItem>();
// 设置 RECT 对象
Rect viewRect = this.GetViewRect ();
// 设置 ITEM RECT 对象
Rect itemRect = this.GetItemRect ();
// 初始化滚动管理
this.selfScrollViewManager = new SelfScrollViewManager (viewRect, itemRect, this.YOffset);
// 初始化引用
GameObject newGameObjectReference = null;
// 初始化元件
SelfScrollItem selfScrollItem = null;
// 设置 Y 偏移
float yOffset = viewRect.y - itemRect.y;
// 初始化子对象
for(int index = 0; index < this.MaxItemCount; index )
{
newGameObjectReference = GameObject.Instantiate(this.ScrollItem.GetTransform().gameObject) as GameObject;
if(newGameObjectReference != null)
{
newGameObjectReference.transform.parent = this.transform;
newGameObjectReference.transform.localScale = Vector3.one;
newGameObjectReference.transform.localPosition = new Vector3(0f, yOffset, 0f);

selfScrollItem = newGameObjectReference.GetComponent<SelfScrollItem>();
if(selfScrollItem != null)
{
yOffset -= (itemRect.y - itemRect.height this.YOffset);
newGameObjectReference.SetActive(true);
selfScrollItem.SetIndex(index);
this.itemList.Add(selfScrollItem);
selfScrollItem.SetData(this.DataList[index]);
}
else
{
newGameObjectReference.SetActive(false);
}
}
}
}
protected virtual void AwakeAfterHandler() {}

/// <summary>
/// 裁剪范围
/// </summary>
/// <returns>The view rect.</returns>
public virtual Rect GetViewRect () { return new Rect (150, 150, -150, -150); }

/// <summary>
/// ITEM 裁剪区域
/// </summary>
/// <returns>The item rect.</returns>
public virtual Rect GetItemRect() { return new Rect(-150, 50, 150, -50); }

void Update()
{
this.UpdateBeforeHandler ();
this.UpdateHandler ();
this.UpdateAfterHandler ();
}

protected virtual void UpdateBeforeHandler() {}

private SelfScrollView selfScrollView;
protected virtual void UpdateHandler()
{
if(!string.IsNullOrEmpty(this.Response))
{
if(UICamera.hoveredObject != null)
{
this.selfScrollView = UICamera.hoveredObject.GetComponent<SelfScrollView>();
if(this.selfScrollView == null) return;
// 如果感觉数据不正确
if(this.Response != this.selfScrollView.Response)
{
this.mousePress = false;
return;
}
}else
{
this.mousePress = false;
return;
}
}
// 如果左键按下
if(Input.GetMouseButtonDown(0))
{
this.mousePosition = Input.mousePosition;
this.mousePress = true;
}

if(Input.GetMouseButtonUp(0))
{
this.mousePress = false;
}

if(this.mousePress)
{
this.offsetPosition = Input.mousePosition - this.mousePosition;
this.mousePosition = Input.mousePosition;

if(directionTypeEnum == SelfScrollDirectionTypeEnum.Vertical)
{
this.VerticalScrollProgress(this.offsetPosition.y);
}
}
}
protected virtual void UpdateAfterHandler() {}

protected virtual void VerticalScrollProgress(float offset)
{
this.selfScrollViewManager.VerticalOperater(offset, this.itemList, this.DataList.Count, this.ItemCallback);
}

protected virtual void ItemCallback(ISelfScrollItem scrollItem)
{
int index = scrollItem.GetIndex ();
if(index < 0 || index >= this.DataList.Count) return;
((SelfScrollItem)scrollItem).SetData(this.DataList[index]);
}
}