一、UI中的点击，拖拉，移入，移出事件。

IEventSystemHandler

EventTrigger事件

二、Drag，Drope 拖拽类 IBeginDragHandler,IDragHandler,IEndDragHandler(拖拽脚本的实现)

实现鼠标拖拽UI移动

代码展示：
using UnityEngine;
using System.Collections;
using UnityEngine.EventSystems;
using System;
using UnityEngine.UI;

public class UIFloatPanelMove : MonoBehaviour,IBeginDragHandler,IDragHandler,IEndDragHandler
{
    void Start()
    {

    }


    void Update()
    {

    }
    /// <summary>
    /// 开始拖拽
    /// </summary>
    /// <param name="eventData"></param>
    public void OnBeginDrag(PointerEventData eventData)
    {
        
    }

    /// <summary>
    /// 推拽中
    /// </summary>
    /// <param name="eventData"></param>
    public void OnDrag(PointerEventData eventData)
    {
        Vector3 offset = new Vector3(eventData.delta.x, eventData.delta.y, 0);
        CanvasScaler canvasScaler = transform.parent.GetComponent<CanvasScaler>();
        if (canvasScaler.uiScaleMode == CanvasScaler.ScaleMode.ScaleWithScreenSize)
        {
            float resolutionX = canvasScaler.referenceResolution.x;
            float resolutionY = canvasScaler.referenceResolution.y;
            float rate = (Screen.width / canvasScaler.referenceResolution.x) * (1 - canvasScaler.matchWidthOrHeight) + (Screen.height / canvasScaler.referenceResolution.y) * canvasScaler.matchWidthOrHeight;
            offset /= rate;
        }
        transform.localPosition += offset;
    }

    /// <summary>
    /// 结束拖拽
    /// </summary>
    /// <param name="eventData"></param>
    public void OnEndDrag(PointerEventData eventData)
    {
        
    }

三、Pointer鼠标指针类 IPointerClickHandler, IPointerEnterHandler, IPointerExitHandler, IPointerDownHandler，IPointerUpHandler(鼠标点击，移入，移出的控制)

using UnityEngine.UI;
using UnityEngine.EventSystems;
using UnityEngine;
using SpacePlanner;
using System;

using SpacePlanner.Core.DataStructure;

//父类，子类可以重写这些方法，进行扩充

/// <summary>
/// 所有UI物体的父类
/// </summary>
public class UIObject : MaskableGraphic, IPointerClickHandler, IScrollHandler, IPointerEnterHandler, IPointerExitHandler, IPointerDownHandler
{
    public Base currentVO;
    public RectTransform body;

    /// <summary>
    /// 全局控制当前选中的Object
    /// </summary>
    public static UIObject currentSelected = null;

    internal virtual void Redraw()
    {
    }


    internal virtual void Redraw_Alan()
    {

    }


    /// <summary>
    /// 鼠标是否悬停在上面
    /// </summary>
    /// <param name="isHover"></param>
    internal virtual void OnHover(bool isHover)
    {

    }

    /// <summary>
    /// 是否被选中
    /// </summary>
    /// <param name="isSelected"></param>
    internal virtual void OnSelected(bool isSelected)
    {
        
    }

    #region 封装多一层，用于外部调用改变选中状态
    public void Select()
    {
        if (currentSelected != null)
            currentSelected.Unselect();
        else
        OnSelected(true);
        currentSelected = this;
    }

    public void Unselect()
    {
        OnSelected(false);
        currentSelected = null;
    }
    #endregion

    /// <summary>
    /// 不做特别的判断
    /// </summary>
    /// <param name="screenPoint"></param>
    /// <param name="eventCamera"></param>
    /// <returns></returns>
    public virtual bool IsRaycastLocationValid(Vector2 screenPoint, Camera eventCamera)
    {
        return true;
    }

    #region EventHandle

    /// <summary>
    /// 屏蔽掉拖拉时触发的OnPointerClick，建议子类重写该函数
    /// </summary>
    /// <param name="eventDat"></param>
    public virtual void OnClick(PointerEventData eventData)
    {

    }

    public void OnPointerClick(PointerEventData eventData)
    {
        if (Input.GetMouseButtonUp(0))//只响应左键
        {
            if (!eventData.dragging)
                OnClick(eventData);
        }
    }

    /// <summary>
    /// 考虑到目前所有继承于他的元素都需要将滚轮事件传递下去，自身不处理该事件
    /// </summary>
    /// <param name="eventData"></param>
    public void OnScroll(PointerEventData eventData)
    {
        EventSystem.current.PropgateEvent(eventData, ExecuteEvents.scrollHandler, gameObject);
    }

    public void OnPointerEnter(PointerEventData eventData)
    {
        if (currentSelected != null) return;
        OnHover(true);
    }

    public void OnPointerExit(PointerEventData eventData)
    {
        if (currentSelected != null) return;
        OnHover(false);
    }

    public void OnPointerDown(PointerEventData eventData)
    {
        if (Input.GetMouseButtonDown(0))//只响应左键
            Select();
    }

    #endregion
}

子类的扩充，已实现自己想要的效果


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

using SpacePlanner;

using SpacePlanner.Core.DataStructure;

public class UIWall : UIObject, ICanvasRaycastFilter, IBeginDragHandler, IDragHandler, IEndDragHandler
{
internal override void OnHover(bool isHover)
    {
        base.OnHover(isHover);
        if (isHover)
            color = new Color(hoverColor.r, hoverColor.g, hoverColor.b, color.a);
        else
            color = new Color(normalColor.r, normalColor.g, normalColor.b, color.a);     
    }

    internal override void OnSelected(bool isSelected)
    {
        base.OnSelected(isSelected);
        if (isSelected)
            color = new Color(hoverColor.r, hoverColor.g, hoverColor.b, color.a);
        else
            color = new Color(normalColor.r, normalColor.g, normalColor.b, color.a);
    }

    public override void OnClick(PointerEventData eventData)
    {
        base.OnClick(eventData);
        //Alan编写
        //检测墙的链接状态
        WallConnectState state = WallConnectMessage.WallConnectCheck(SPApplication.Instance.Space, (Wall)currentVO);
        CreateFloatUI(state);
    }

    public void OnBeginDrag(PointerEventData eventData)
    {
        //FPBApplication.Instance.SendNotification(ApplicationConstants.TO_C_BEGIN_MOVE_WALL, currentVO);
    }

    public void OnDrag(PointerEventData eventData)
    {
        VOAndVector3 data = new VOAndVector3(currentVO as Wall, TransformHelper.ScreenToRealWorldPoint(Input.mousePosition));
        //FPBApplication.Instance.SendNotification(ApplicationConstants.TO_C_MOVING_WALL, data);
    }

    //IEndDragHandler
    public void OnEndDrag(PointerEventData eventData)
    {
        //FPBApplication.Instance.SendNotification(ApplicationConstants.TO_C_MOVE_WALL_DONE, currentVO);
    }



}

四、Select点选类 IUpdateSelectedHandle ISelectHandler IDeselectHandler

五、Input输入类 IScrollHandler,IMoveHandler ISubmitHandler ICancelHandelr

六、扩展文献，程序动态设置实现。
http://blog.csdn.net/baidu_28955655/article/details/51387446