UGUI优化注意

一、资源管理及命名规则

通用和各个功能区分，提高图集利用率

二、纹理格式的选择

Android

ETC1不带透明通道，ECT2带透明通道

Unity RGBA Crunched ETC2会比ETC2加载更快，而且包体会更小

通道分离，Unity还能将图片设置成alpha8格式

IOS

不带透明推荐PVRTC（也可透明）ASTC5x5，透明ASTC4x4

ASTC大小计算

像素大小 = 16-bytes / 分块宽高 * 8-bit

压缩率 = 原始像素大小（32-bit） / 像素块大小

图像大小 = 原始图片大小 / 压缩率

注：一张1024*1024图片原始为4M(RGBA32)32位

选择要求

ETC1、ETC2以及ASTC 4X4要求尺寸大小被4整除

PVRTC要求正方形2的幂

ETC2只支持OpenGL ES 3.0以上的Android（约2013年以后）

ASTC只支持苹果A8以后的设备（iphone6以后）

三、UI事件注意

取消掉UI中用不到的raycastTarget

取消没有事件响应的Canvas可以不用GraphicRaycaster

可以利用脚本查看是否有事件DebugUILine

#if UNITY_EDITOR
using UnityEngine;
using UnityEngine.UI;
public class DebugUILine : MonoBehaviour
{
		static Vector3[] fourCorners = new Vector3[4];
		void OnDrawGizmos()
		{
			foreach (MaskableGraphic g in GameObject.FindObjectsOfType<MaskableGraphic>())
			{
				if (g.raycastTarget)
				{
					RectTransform rectTransform = g.transform as RectTransform;
					rectTransform.GetWorldCorners(fourCorners);
					Gizmos.color = Color.blue;
					for (int i = 0; i < 4; i++)
						Gizmos.DrawLine(fourCorners[i], fourCorners[(i + 1) % 4]);

				}
			}
		}
}
#endif

可以给任意利用脚本给任意物体增加事件UIEventTriggerBox

using UnityEngine;
using UnityEngine.EventSystems;

public class UIEventTriggerBox : EventTrigger
{
    public System.Action onClick;
    public System.Action onDown;
    public System.Action onEnter;
    public System.Action onExit;
    public System.Action onUp;
    public System.Action onSelect;
    public System.Action onUpdateSelect;

    static public UIEventTriggerBox Get(GameObject go)
    {
        UIEventTriggerBox listener = go.GetComponent<UIEventTriggerBox>();
        if (listener == null) listener = go.AddComponent<UIEventTriggerBox>();
        return listener;
    }

    public override void OnPointerClick(PointerEventData eventData)
    {
        if (onClick != null) onClick();
    }
    public override void OnPointerDown(PointerEventData eventData)
    {
        if (onDown != null) onDown();
    }
    public override void OnPointerEnter(PointerEventData eventData)
    {
        if (onEnter != null) onEnter();
    }
    public override void OnPointerExit(PointerEventData eventData)
    {
        if (onExit != null) onExit();
    }
    public override void OnPointerUp(PointerEventData eventData)
    {
        if (onUp != null) onUp();
    }
    public override void OnSelect(BaseEventData eventData)
    {
        if (onSelect != null) onSelect();
    }
    public override void OnUpdateSelected(BaseEventData eventData)
    {
        if (onUpdateSelect != null) onUpdateSelect();
    }
}