【Unity2D入门教程】简单制作战机弹幕射击游戏⑥最终回扩展其它范围的内容

制作分数和生命的UI：

由于我们前面没有做类似的UI所以这里教大伙一下基本思路：

首先我们创建一个canvas用来创建两个Text用来显示分数和生命的UI

蓝色的是分数黄色的是生命

我们创建一个scoreplay的脚本挂载在text上

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
public class ScoreDisplay : MonoBehaviour
{
    Text scoreText;
    GameSeesion gameSession;
    private void Start()
    {
        scoreText = GetComponent();
        gameSession = FindObjectOfType();
    }
    private void Update()
    {
        scoreText.text = gameSession.GetScore().ToString();
    }
}

创建一个空对象gamesession还有一个同名脚本挂载在它上面：

接着我们改一下Player和Enemy的脚本

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Player : MonoBehaviour
{


    [Header("玩家移动")]
    [SerializeField] float ySpeed = 10f;
    [SerializeField] float xSpeed = 10f;
    [SerializeField] float padding = 1f;

    [Header("Play Health")]
    [SerializeField] int health = 500;

    [Header("ProjectTile")]
    [SerializeField] GameObject laserPrefab;
    [SerializeField] float projectTileSpeed = 10f;
    [SerializeField] float projectTileFiringPeriod = 0.1f;
    //战机在屏幕能移动的坐标
    float xMin;
    float xMax;
    float yMin;
    float yMax;

    //协程的编程是指在不堵塞主线程的情况下执行某些特定的函数
    Coroutine fireCoroutine;

    [SerializeField] AudioClip deathSFX;
    [SerializeField] [Range(0, 1)] float deathSoundVolume = 0.75f;
    [SerializeField] AudioClip shootSFX;
    [SerializeField] [Range(0, 1)] float shootSoundVolume = 0.55f;
    void Start()
    {
        SetUpMoveBoundaries();
    }
    private void SetUpMoveBoundaries()
    {
        Camera gameCamera = Camera.main;
        //之前的视频说过，Camera.main.ViewportToWorldPoint()是将摄像机视角的坐标转化为世界坐标然后padding是防止战机出屏幕边缘
        xMin = gameCamera.ViewportToWorldPoint(new Vector3(0, 0, 0)).x + padding;
        xMax = gameCamera.ViewportToWorldPoint(new Vector3(1, 0, 0)).x - padding;
        yMin = gameCamera.ViewportToWorldPoint(new Vector3(0, 0, 0)).y + padding;
        yMax = gameCamera.ViewportToWorldPoint(new Vector3(0, 1, 0)).y - padding;
    }
    void Update()
    {
        Move();
        Fire();
    }
    private void Move()
    {
        //Input Manager上两个监控键盘上WSAD按键而生成-1到1值的
        var deltaY = Input.GetAxis("Vertical") * Time.deltaTime * ySpeed;
        var deltaX = Input.GetAxis("Horizontal") * Time.deltaTime * xSpeed;
       // Debug.Log(deltaX);
       //限制移动范围
        var newXPos = Mathf.Clamp(transform.position.x + deltaX, xMin, xMax);
        var newYPos = Mathf.Clamp(transform.position.y + deltaY, yMin, yMax);

        transform.position = new Vector2(newXPos,newYPos);
    }
    private void Fire()
    {
        if (Input.GetButtonDown("Fire1"))
        {
           fireCoroutine =  StartCoroutine(FireContinuously());
        }
        if (Input.GetButtonUp("Fire1"))//这个Fire1也是Input Manager上的
        {
            StopCoroutine(fireCoroutine); //暂停某个协程
            // StopAllCoroutines();
        }
    }
    //协程函数是用关键字迭代器IEnumerator而且一定要用yield关键词返回
    IEnumerator FireContinuously()
    {
        while (true)
        {
            GameObject laser = Instantiate(laserPrefab, transform.position, Quaternion.identity) as GameObject; //生成子弹
            laser.GetComponent().velocity = new Vector2(0, projectTileSpeed); //给子弹一个向上的力
            AudioSource.PlayClipAtPoint(shootSFX, Camera.main.transform.position, shootSoundVolume);
            yield return new WaitForSeconds(projectTileFiringPeriod); //下一颗子弹发生的间隔时间
        }
    }

    private void OnTriggerEnter2D(Collider2D other)
    {
        DamageDealer damageDealer = other.gameObject.GetComponent();
        if (!damageDealer) { return; }
        ProcessHit(damageDealer);
    }

    private void ProcessHit(DamageDealer damageDealer)
    {
        health -= damageDealer.GetDamage(); //减去收到的伤害
        damageDealer.Hit();
        if (health