按键控制移动

using UnityEngine;
using System.Collections;

public class MyMoveControll : MonoBehaviour {

    // 自定义方向系数
    public const int PLAY_UP     = 0;
    public const int PLAY_RIGHT = 1;
    public const int PLAY_DOWN     = 2;
    public const int PLAY_LEFT     = 3;

    // 人物速度 ( 为了方便测试, 可更改为 public 属性, 在面板中设置数值 )
    private int moveSpeed = 10;
    // 人物当前方向状态
    private int currState = 0;

    void Awake()
    {
        currState = PLAY_UP;
    }

    void Update () 
    {
        KeyControll ();

        // Draw Line
        Quaternion qua = transform.rotation;
        Vector3 f = transform.position + (qua * Vector3.forward) * 5;
        Debug.DrawLine (transform.position, f, Color.red);
    }

    // 按钮控制
    void KeyControll()
    {
        float xMovement = Input.GetAxis("Horizontal");
        float zMovement = Input.GetAxis("Vertical");

        float tempAngle = Mathf.Atan2( zMovement, xMovement );

        xMovement *= Mathf.Abs( Mathf.Cos ( tempAngle ) );
        zMovement *= Mathf.Abs( Mathf.Sin ( tempAngle ) );

        Vector3 moveDirection = new Vector3( xMovement, 0, zMovement );
        moveDirection = transform.TransformDirection( moveDirection );
        // 防止前移
        moveDirection.y = 0;

        if (Input.GetKey (KeyCode.A)) 
        {
            GetComponent< CharacterController > ().Move( -1 * moveDirection * Time.deltaTime );
        } 
        else if (Input.GetKey (KeyCode.D)) 
        {
            GetComponent< CharacterController > ().Move( moveDirection * Time.deltaTime );
        }
        else if (Input.GetKey (KeyCode.S)) 
        {
            GetComponent< CharacterController > ().Move( -1 * moveDirection * Time.deltaTime );
        }
        else if (Input.GetKey (KeyCode.W)) 
        {
            GetComponent< CharacterController > ().Move( moveDirection * Time.deltaTime );
        }
    }
}

按键获取方式【 2 】

float KeyVertical = Input.GetAxis("Vertical");
float KeyHorizontal = Input.GetAxis("Horizontal");

if(KeyVertical == -1)
{
        setGameState(PLAY_LEFT);
}
else if(KeyVertical == 1)        
{
        setGameState(PLAY_RIGHT);
}

if(KeyHorizontal == 1)
{
        setGameState(PLAY_DOWN);
}
else if(KeyHorizontal == 1)
{
        setGameState(PLAY_UP);
}