using UnityEngine;using System.Collections;/** *两个背景图片平移  */public class BackgroundController : MonoBehaviour {    public SpriteRenderer back1;            public SpriteRenderer back2;            public Sprite [] textureList;           //背景图片集合     public int speed = 1;                   //背景平移的速度     public Transform endPosition;           //到达该位置,把背景移动到开始位置     public Transform startPosition;         //背景从开始位置移动到结束位置            private int backIndex;                      void Start()     {        back1.sprite = textureList[0];        back2.sprite = textureList[1];        backIndex = 2;    }    void Update()     {        if (backIndex >= textureList.Length)         {            backIndex = textureList.Length - 1;        }        //两个图片的平移        back1.transform.position = new Vector3(back1.transform.position.x - speed * Time.deltaTime, back1.transform.position.y, back1.transform.position.z);        back2.transform.position = new Vector3(back2.transform.position.x - speed * Time.deltaTime, back2.transform.position.y, back2.transform.position.z);        //到达结束位置,回到开始位置,切换图片        if (back1.transform.position.x <= endPosition.transform.position.x)         {            back1.transform.position = startPosition.position;            back1.sprite = textureList[backIndex];            backIndex++;        }        if (back2.transform.position.x <= endPosition.transform.position.x)        {            back2.transform.position = startPosition.position;            back2.sprite = textureList[backIndex];            backIndex++;        }    }}