上下左右 键控制人移动

出自Unity3D开发一书，

这个脚本式只是简单的控制人物移动，不是很理想，但是可以学习 通过 上 、下、左、右  按键怎么实现任务的移动

 using UnityEngine;
 using System.Collections;

 public class MoveByADSW : MonoBehaviour {

     public const int HERO_UP = 0;
     public const int HERO_RIGHT = 1;
     public const int HERO_DOWN = 2;
     public const int HERO_LEFT = 3;

     //人物当前行走的方向状态
     public int state = 0;
     //人物移动速度
     public int moveSpeed = 2;

     //初始化人物位置
     public void Awake()
     {
         state = HERO_UP;
     }
     // Use this for initialization
     void Start () {

     }

     // Update is called once per frame
     void Update () {
         //获取控制的方向， 上下左右，
         float KeyVertical = Input.GetAxis("Vertical");
         float KeyHorizontal = Input.GetAxis("Horizontal");
         Debug.Log("keyVertical" + KeyVertical);
         Debug.Log("keyHorizontal" + KeyHorizontal);
         if(KeyVertical == -1)
         {
             setHeroState(HERO_DOWN);
         }
         else if(KeyVertical == 1)
         {
             setHeroState(HERO_UP);
         }
         if(KeyHorizontal == 1)
         {
             setHeroState(HERO_RIGHT);
         }
         else if(KeyHorizontal == -1)
         {
             setHeroState(HERO_LEFT);
         }

         if(KeyVertical == 0 && KeyHorizontal == 0)
         {
             animation.Play("idle");
         }
     }

     void setHeroState(int newState)
     {
         //根据当前人物方向与上一次备份的方向计算出模型旋转的角度
         int rotateValue = (newState - state) * 90;
         Vector3 transformValue = new Vector3();

         //播放行走动画
         animation.Play("walk");

         //模型移动的位置数值
         switch(newState)
         {
         case HERO_UP:
             transformValue = Vector3.forward * Time.deltaTime;
             break;
         case HERO_DOWN:
             transformValue = (-Vector3.forward) * Time.deltaTime;
             break;
         case HERO_LEFT:
             transformValue = Vector3.left * Time.deltaTime;
             break;
         case HERO_RIGHT:
             transformValue = (-Vector3.left) * Time.deltaTime;
             break;
         }

         transform.Rotate(Vector3.up, rotateValue);
         //移动人物
         transform.Translate(transformValue * moveSpeed, Space.World);
         state = newState;
     }
 }