C#入门之方法的重载与返回值核心概念与实践详解

// Unity C# 示例代码
using UnityEngine;

public class ExampleScript : MonoBehaviour
{
    // Start is called before the first frame update
    void Start()
    {
        Debug.Log("Hello, Unity!");
    }
    
    // Update is called once per frame
    void Update()
    {
        // 每帧执行的逻辑
    }
}

using UnityEngine;

/// <summary>
/// Unity组件示例类
/// </summary>
public class UnityDemo : MonoBehaviour
{
    [Header("基本设置")]
    [SerializeField] private string objectName = "Unity对象";
    [SerializeField] private float moveSpeed = 5f;
    
    private Transform cachedTransform;
    
    /// <summary>
    /// 初始化方法
    /// </summary>
    private void Awake()
    {
        cachedTransform = transform;
        Debug.Log($"{objectName} 已初始化");
    }
    
    /// <summary>
    /// 开始方法
    /// </summary>
    private void Start()
    {
        // 初始化逻辑
    }
    
    /// <summary>
    /// 更新方法
    /// </summary>
    private void Update()
    {
        // 移动逻辑
        float horizontal = Input.GetAxis("Horizontal");
        float vertical = Input.GetAxis("Vertical");
        
        Vector3 movement = new Vector3(horizontal, 0, vertical);
        cachedTransform.Translate(movement * moveSpeed * Time.deltaTime);
    }
}

// 右键 Assets 文件夹
// Create -> C# Script
// 命名为 MyFirstScript

using UnityEngine;

public class MyFirstScript : MonoBehaviour
{
    // 在Inspector面板中显示的变量
    public int health = 100;
    public float speed = 5.0f;
    public string playerName = "Player1";
    
    void Start()
    {
        Debug.Log($"玩家 {playerName} 已创建，生命值: {health}");
    }
    
    void Update()
    {
        if (Input.GetKeyDown(KeyCode.Space))
        {
            Debug.Log("空格键被按下");
        }
    }
}

using UnityEngine;

public class PlayerController : MonoBehaviour
{
    [Header("移动设置")]
    public float moveSpeed = 5f;
    public float rotateSpeed = 100f;
    
    private Rigidbody rb;
    
    private void Awake()
    {
        rb = GetComponent<Rigidbody>();
    }
    
    private void Update()
    {
        // 获取输入
        float horizontal = Input.GetAxis("Horizontal");
        float vertical = Input.GetAxis("Vertical");
        
        // 移动
        Vector3 movement = new Vector3(horizontal, 0, vertical);
        transform.Translate(movement * moveSpeed * Time.deltaTime);
        
        // 旋转
        if (Input.GetKey(KeyCode.Q))
        {
            transform.Rotate(0, -rotateSpeed * Time.deltaTime, 0);
        }
        if (Input.GetKey(KeyCode.E))
        {
            transform.Rotate(0, rotateSpeed * Time.deltaTime, 0);
        }
    }
}

using UnityEngine;
using UnityEngine.UI;

public class UIManager : MonoBehaviour
{
    [Header("UI组件")]
    public Text scoreText;
    public Button startButton;
    public Slider healthSlider;
    
    private int score = 0;
    
    private void Start()
    {
        // 绑定按钮事件
        startButton.onClick.AddListener(OnStartButtonClicked);
        
        // 初始化UI
        UpdateScoreDisplay();
        healthSlider.value = 100;
    }
    
    public void AddScore(int points)
    {
        score += points;
        UpdateScoreDisplay();
    }
    
    private void UpdateScoreDisplay()
    {
        scoreText.text = $"分数: {score}";
    }
    
    private void OnStartButtonClicked()
    {
        Debug.Log("游戏开始！");
        // 开始游戏逻辑
    }
}

using UnityEngine;
using System;

/// <summary>
/// 单例模式管理器示例
/// </summary>
public class GameManager : MonoBehaviour
{
    // 单例实例
    public static GameManager Instance { get; private set; }
    
    [Header("游戏设置")]
    [SerializeField] private int maxLives = 3;
    [SerializeField] private float gameTime = 0f;
    
    // 事件
    public event Action<int> OnLivesChanged;
    public event Action<float> OnTimeChanged;
    
    private int currentLives;
    private bool isGameRunning;
    
    private void Awake()
    {
        // 单例初始化
        if (Instance != null && Instance != this)
        {
            Destroy(gameObject);
            return;
        }
        Instance = this;
        DontDestroyOnLoad(gameObject);
        
        // 初始化游戏状态
        currentLives = maxLives;
    }
    
    private void Update()
    {
        if (isGameRunning)
        {
            gameTime += Time.deltaTime;
            OnTimeChanged?.Invoke(gameTime);
        }
    }
    
    public void StartGame()
    {
        isGameRunning = true;
        gameTime = 0f;
        currentLives = maxLives;
        OnLivesChanged?.Invoke(currentLives);
    }
    
    public void LoseLife()
    {
        currentLives--;
        OnLivesChanged?.Invoke(currentLives);
        
        if (currentLives <= 0)
        {
            GameOver();
        }
    }
    
    private void GameOver()
    {
        isGameRunning = false;
        Debug.Log("游戏结束！");
    }
}

// 方案1: 使用public（不推荐）
public int value;

// 方案2: 使用SerializeField（推荐）
[SerializeField] private int value;

// 方案3: 添加Header属性
[Header("设置")]
[SerializeField] private int value;

// 方案4: 添加Range属性
[Range(0, 100)]
[SerializeField] private int value;

// 错误写法
private void Start()
{
    rb.AddForce(Vector3.up);  // rb可能为null
}

// 正确写法
private Rigidbody rb;

private void Awake()
{
    rb = GetComponent<Rigidbody>();
}

private void Start()
{
    if (rb != null)
    {
        rb.AddForce(Vector3.up);
    }
    else
    {
        Debug.LogError("Rigidbody组件未找到！");
    }
}

// 优化1: 缓存组件引用
private Transform cachedTransform;

private void Awake()
{
    cachedTransform = transform;  // 缓存Transform
}

// 优化2: 避免在Update中使用Find
private GameObject target;

private void Start()
{
    target = GameObject.Find("Target");  // 只在Start中查找一次
}

// 优化3: 使用对象池
private List<GameObject> objectPool = new List<GameObject>();

public GameObject GetObject()
{
    foreach (var obj in objectPool)
    {
        if (!obj.activeInHierarchy)
        {
            obj.SetActive(true);
            return obj;
        }
    }
    // 创建新对象...
    return null;
}

// 1. 使用有意义的变量名
public float playerMoveSpeed = 5f;  // ✅ 好
public float s = 5f;  // ❌ 不好

// 2. 添加注释和文档
/// <summary>
/// 玩家控制器，处理玩家输入和移动
/// </summary>
public class PlayerController : MonoBehaviour
{
    /// <summary>
    /// 玩家移动速度
    /// </summary>
    [Tooltip("玩家移动速度，单位：米/秒")]
    [SerializeField] private float moveSpeed = 5f;
}

// 3. 使用SerializeField而非public
[SerializeField] private int health;  // ✅ 推荐
public int health;  // ❌ 不推荐

// 4. 使用事件解耦
public event Action OnPlayerDeath;

private void Die()
{
    OnPlayerDeath?.Invoke();
}