Unity3D UGUI事件处理

由于Unity3D官方出了新的UI系统，导致了不少的NGUI用户转向了UGUI。虽然现在UGUI相关的控件脚本等不及NGUI，但随着AssetStore里各种插件的开发，UGUI的发展前景还是比较看好的。

UGUI里面的事件处理代码跟NGUI不同，主要是通过实现接口方法来执行事件。

提供的接口如下:

• IPointerEnterHandler - OnPointerEnter - Called when a pointer enters the object
• IPointerExitHandler - OnPointerExit - Called when a pointer exits the object
• IPointerDownHandler - OnPointerDown - Called when a pointer is pressed on the object
• IPointerUpHandler - OnPointerUp - Called when a pointer is released (called on the original the pressed object)
• IPointerClickHandler - OnPointerClick - Called when a pointer is pressed and released on the same object
• IInitializePotentialDragHandler - OnInitializePotentialDrag - Called when a drag target is found, can be used to initialise values
• IBeginDragHandler - OnBeginDrag - Called on the drag object when dragging is about to begin
• IDragHandler - OnDrag - Called on the drag object when a drag is happening
• IEndDragHandler - OnEndDrag - Called on the drag object when a drag finishes
• IDropHandler - OnDrop - Called on the object where a drag finishes
• IScrollHandler - OnScroll - Called when a mouse wheel scrolls
• IUpdateSelectedHandler - OnUpdateSelected - Called on the selected object each tick
• ISelectHandler - OnSelect - Called when the object becomes the selected object
• IDeselectHandler - OnDeselect - Called on the selected object becomes deselected
• IMoveHandler - OnMove - Called when a move event occurs (left, right, up, down, ect)
• ISubmitHandler - OnSubmit - Called when the submit button is pressed
• ICancelHandler - OnCancel - Called when the cancel button is pressed

其实很好理解，就是一些点击进入拖动等操作，实现相应的接口即可。

例如点击事件:

using UnityEngine;
using System.Collections;
using UnityEngine.EventSystems;

public class TestPointerEnterEvent : MonoBehaviour,IPointerClickHandler
{
    public void OnPointerClick(PointerEventData data)
    {
        Debug.Log("Pointer click.");
    }
}

不过UGUI目前在鼠标事件和控件事件上有重叠，比如在点击控件的时候没有屏蔽掉鼠标事件，我也只是用其他方法来解决的，但我在stackoverflow上搜索的，暂时还没有完美的解决方案，不知道后续要怎么搞。