GFramework/docs/zh-CN/best-practices/error-handling.md

错误处理最佳实践

本指南介绍 GFramework 中的错误处理模式和最佳实践，帮助你构建健壮、可维护的游戏应用。

📋 目录

• 概述
• 核心概念
• Result 模式
• Option 模式
• 异常处理
• 日志记录
• 用户反馈
• 错误恢复
• 最佳实践
• 常见问题

概述

为什么错误处理很重要

良好的错误处理是构建健壮应用的基础：

• 提高稳定性：优雅地处理异常情况，避免崩溃
• 改善用户体验：提供清晰的错误提示和恢复选项
• 简化调试：记录详细的错误信息，快速定位问题
• 增强可维护性：使用类型安全的错误处理模式

GFramework 的错误处理策略

GFramework 提供多种错误处理机制：

1. Result<T> 模式：函数式错误处理，类型安全
2. Option<T> 模式：处理可空值，避免 null 引用
3. 异常处理：处理不可恢复的错误
4. 日志系统：记录错误信息和调试数据

核心概念

错误类型

根据错误的性质和处理方式，可以分为以下几类：

1. 可预期的错误

这类错误是业务逻辑的一部分，应该使用 Result 或 Option 模式处理：

// 示例：用户输入验证
public Result<PlayerData> ValidatePlayerName(string name)
{
    if (string.IsNullOrWhiteSpace(name))
        return Result<PlayerData>.Failure("玩家名称不能为空");

    if (name.Length < 3)
        return Result<PlayerData>.Failure("玩家名称至少需要 3 个字符");

    if (name.Length > 20)
        return Result<PlayerData>.Failure("玩家名称不能超过 20 个字符");

    return Result<PlayerData>.Success(new PlayerData { Name = name });
}

2. 不可预期的错误

这类错误通常是程序错误或系统故障，应该使用异常处理：

// 示例：文件系统错误
public async Task<SaveData> LoadSaveFileAsync(string path)
{
    try
    {
        var json = await File.ReadAllTextAsync(path);
        return JsonSerializer.Deserialize<SaveData>(json);
    }
    catch (FileNotFoundException ex)
    {
        _logger.Error($"存档文件不存在: {path}", ex);
        throw new SaveSystemException("无法加载存档文件", ex);
    }
    catch (JsonException ex)
    {
        _logger.Error($"存档文件格式错误: {path}", ex);
        throw new SaveSystemException("存档文件已损坏", ex);
    }
}

3. 可空值

使用 Option 模式处理可能不存在的值：

// 示例：查找玩家
public Option<Player> FindPlayerById(string playerId)
{
    var player = _players.FirstOrDefault(p => p.Id == playerId);
    return player != null ? Option<Player>.Some(player) : Option<Player>.None;
}

错误传播

错误应该在合适的层级处理，不要过早捕获：

// ✅ 好的做法：让错误向上传播
public class InventorySystem : AbstractSystem
{
    public Result<Item> AddItem(string itemId, int quantity)
    {
        // 验证参数
        var validationResult = ValidateAddItem(itemId, quantity);
        if (validationResult.IsFaulted)
            return validationResult;

        // 检查空间
        var spaceResult = CheckInventorySpace(quantity);
        if (spaceResult.IsFaulted)
            return Result<Item>.Failure(spaceResult.Exception);

        // 添加物品
        var item = CreateItem(itemId, quantity);
        _items.Add(item);

        return Result<Item>.Success(item);
    }
}

// ❌ 避免：过早捕获错误
public class InventorySystem : AbstractSystem
{
    public Result<Item> AddItem(string itemId, int quantity)
    {
        try
        {
            // 所有操作都在 try 块中
            ValidateAddItem(itemId, quantity);
            CheckInventorySpace(quantity);
            var item = CreateItem(itemId, quantity);
            _items.Add(item);
            return Result<Item>.Success(item);
        }
        catch (Exception ex)
        {
            // 捕获所有异常，丢失了错误的具体信息
            return Result<Item>.Failure("添加物品失败");
        }
    }
}

错误恢复

设计错误恢复策略，提供降级方案：

// 示例：多级降级策略
public async Task<GameConfig> LoadConfigAsync()
{
    // 1. 尝试从云端加载
    var cloudResult = await TryLoadFromCloudAsync();
    if (cloudResult.IsSuccess)
    {
        _logger.Info("从云端加载配置成功");
        return cloudResult.Match(succ: c => c, fail: _ => null);
    }

    // 2. 尝试从本地缓存加载
    var cacheResult = await TryLoadFromCacheAsync();
    if (cacheResult.IsSuccess)
    {
        _logger.Warn("云端加载失败，使用本地缓存");
        return cacheResult.Match(succ: c => c, fail: _ => null);
    }

    // 3. 使用默认配置
    _logger.Error("所有配置源加载失败，使用默认配置");
    return GetDefaultConfig();
}

Result 模式

基本用法

Result<T> 是一个函数式类型，表示操作可能成功（包含值）或失败（包含异常）：

// 创建成功结果
var successResult = Result<int>.Success(42);

// 创建失败结果
var failureResult = Result<int>.Failure(new Exception("操作失败"));
var failureResult2 = Result<int>.Failure("操作失败"); // 使用字符串

// 检查状态
if (result.IsSuccess)
{
    var value = result.Match(succ: v => v, fail: _ => 0);
}

if (result.IsFaulted)
{
    var error = result.Exception;
}

链式操作

Result 支持函数式编程的链式操作：

// Map：转换成功值
var result = Result<int>.Success(42)
    .Map(x => x * 2)           // Result<int>(84)
    .Map(x => x.ToString());   // Result<string>("84")

// Bind：链式转换，可能失败
var result = Result<string>.Success("42")
    .Bind(s => int.TryParse(s, out var i)
        ? Result<int>.Success(i)
        : Result<int>.Failure("解析失败"))
    .Map(i => i * 2);

// Ensure：验证条件
var result = Result<int>.Success(42)
    .Ensure(x => x > 0, "值必须为正数")
    .Ensure(x => x < 100, "值必须小于 100");

// OnSuccess/OnFailure：执行副作用
result
    .OnSuccess(value => _logger.Info($"成功: {value}"))
    .OnFailure(ex => _logger.Error($"失败: {ex.Message}"));

实际应用示例

示例 1：用户注册

public class UserRegistrationSystem : AbstractSystem
{
    public Result<User> RegisterUser(string username, string email, string password)
    {
        return ValidateUsername(username)
            .Bind(_ => ValidateEmail(email))
            .Bind(_ => ValidatePassword(password))
            .Bind(_ => CheckUsernameAvailability(username))
            .Bind(_ => CheckEmailAvailability(email))
            .Map(_ => CreateUser(username, email, password))
            .OnSuccess(user => {
                _logger.Info($"用户注册成功: {username}");
                this.SendEvent(new UserRegisteredEvent { User = user });
            })
            .OnFailure(ex => _logger.Warn($"用户注册失败: {ex.Message}"));
    }

    private Result<string> ValidateUsername(string username)
    {
        if (string.IsNullOrWhiteSpace(username))
            return Result<string>.Failure("用户名不能为空");

        if (username.Length < 3 || username.Length > 20)
            return Result<string>.Failure("用户名长度必须在 3-20 个字符之间");

        if (!Regex.IsMatch(username, @"^[a-zA-Z0-9_]+$"))
            return Result<string>.Failure("用户名只能包含字母、数字和下划线");

        return Result<string>.Success(username);
    }

    private Result<string> ValidateEmail(string email)
    {
        if (string.IsNullOrWhiteSpace(email))
            return Result<string>.Failure("邮箱不能为空");

        if (!Regex.IsMatch(email, @"^[^@\s]+@[^@\s]+\.[^@\s]+$"))
            return Result<string>.Failure("邮箱格式不正确");

        return Result<string>.Success(email);
    }

    private Result<string> ValidatePassword(string password)
    {
        if (string.IsNullOrWhiteSpace(password))
            return Result<string>.Failure("密码不能为空");

        if (password.Length < 8)
            return Result<string>.Failure("密码长度至少为 8 个字符");

        if (!passwordchar.IsUpper))
            return Result<string>.Failure("密码必须包含至少一个大写字母");

        if (!password.Any(char.IsDigit))
            return Result<string>.Failure("密码必须包含至少一个数字");

        return Result<string>.Success(password);
    }

    private Result<bool> CheckUsernameAvailability(string username)
    {
        var exists = _userRepository.ExistsByUsername(username);
        return exists
            ? Result<bool>.Failure("用户名已被使用")
            : Result<bool>.Success(true);
    }

    private Result<bool> CheckEmailAvailability(string email)
    {
    var exists = _userRepository.ExistsByEmail(email);
        return exists
            ? Result<bool>.Failure("邮箱已被注册")
            : Result<bool>.Success(true);
    }

    private User CreateUser(string username, string email, string password)
    {
        var user = new User
        {
            Id = Guid.NewGuid().ToString(),
            Username = username,
            Email = email,
            PasswordHash = HashPassword(password),
            CreatedAt = DateTime.UtcNow
        };

        _userRepository.Add(user);
        return user;
    }
}

示例 2：物品交易

public class TradingSystem : AbstractSystem
{
    public Result<Trade> ExecuteTrade(string sellerId, string buyerId, string itemId, int price)
    {
        return ValidateTradeParticipants(sellerId, buyerId)
            .Bind(_ => ValidateItem(sellerId, itemId))
            .Bind(_ => ValidateBuyerFunds(buyerId, price))
            .Bind(_ => TransferItem(sellerId, buyerId, itemId))
            .Bind(_ =&gerCurrency(buyerId, sellerId, price))
            .Map(_ => CreateTradeRecord(sellerId, buyerId, itemId, price))
            .OnSuccess(trade => {
                _logger.Info($"交易完成: {trade.Id}");
                this.SendEvent(new TradeCompletedEvent { Trade = trade });
            })
            .OnFailure(ex => {
                _logger.Error($"交易失败: {ex.Message}");
                RollbackTrade(sellerId, buyerId, itemId, price);
            });
    }

    private Result<bool> ValidateTradeParticipants(string sellerId, string buyerId)
    {
        if (sellerId == buyerId)
            return Result<bool>.Failure("不能与自己交易");

        var seller = _playerRepository.GetById(sellerId);
        if (seller == null)
            return Result<bool>.Failure("卖家不存在");

        var buyer = _playerRepository.GetById(buyerId);
        if (buyer == null)
            return Result<bool>.Failure("买家不存在");

        return Result<bool>.Success(true);
    }

    private Result<bool> ValidateItem(string sellerId, string itemId)
    {
        var inventory = _inventoryRepository.GetByPlayerId(sellerId);
        var item = inventory.Items.FirstOrDefault(i => i.Id == itemId);

        if (item == null)
            return Result<bool>.Failure("物品不存在");

        if (!item.IsTradeable)
            return Result<bool>.Failure("该物品不可交易");

        return Result<bool>.Success(true);
    }

    private Result<bool> ValidateBuyerFunds(string buyerId, int price)
    {
        var buyer = _playerRepository.GetById(buyerId);
        if (buyer.Currency < price)
            return Result<bool>.Failure($"金币不足，需要 {price}，当前 {buyer.Currency}");

        return Result<bool>.Success(true);
    }
}

异步操作

Result 支持异步操作：

// 异步 Map
var result = await Result<int>.Success(42)
    .MapAsync(async x => await GetUserDataAsync(x));

// 异步 Bind
var result = await Result<string>.Success("user123")
    .BindAsync(async userId => await LoadUserAsync(userId));

// TryAsync：安全执行异步操作
var result = await ResultExtensions.TryAsync(async () =>
{
    var data = await LoadDataAsync();
    return ProcessData(data);
});

组合多个 Result

// 组合多个结果，全部成功才返回成功
var results = new[]
{
    ValidateUsername("player1"),
    ValidateEmail("player1@example.com"),
    ValidatePassword("Password123")
};

var combinedResult = results.Combine(); // Result<List<string>>

if (combinedResult.IsSuccess)
{
    _logger.Info("所有验证通过");
}
else
{
    _logger.Error($"验证失败: {combinedResult.Exception.Message}");
}

Option 模式

基本用法

Option<T> 用于表示可能存在或不存在的值，避免 null 引用异常：

// 创建 Some（有值）
var someOption = Option<int>.Some(42);

// 创建 None（无值）
var noneOption = Option<int>.None;

// 检查状态
if (option.IsSome)
{
    var value = option.GetOrElse(0);
}

if (option.IsNone)
{
    _logger.Warn("值不存在");
}

常用操作

// GetOrElse：获取值或返回默认值
var value = option.GetOrElse(0);
var value2 = option.GetOrElse(() => GetDefaultValue());

// Map：转换值
var mapped = option.Map(x => x * 2);

// Bind：链式转换
var bound = option.Bind(x => x > 0
    ? Option<string>.Some(x.ToString())
    : Option<string>.None);

// Filter：过滤值
var filtered = option.Filter(x => x > 0);

// Match：模式匹配
var result = option.Match(
    some: value => $"值: {value}",
    none: () => "无值"
);

实际应用示例

示例 1：查找玩家

public class PlayerSystem : AbstractSystem
{
    public Option<Player> FindPlayerById(string playerId)
    {
        var player = _players.FirstOrDefault(p => p.Id == playerId);
        return player != null ? Option<Player>.Some(player) : Option<Player>.None;
    }

    public Option<Player> FindPlayerByName(string playerName)
    {
        var player = _players.FirstOrDefault(p => p.Name == playerName);
        return player != null ? Option<Player>.Some(player) : Option<Player>.None;
    }

    public void UpdatePlayerScore(string playerId, int score)
    {
        FindPlayerById(playerId).Match(
            some: player => {
                player.Score += score;
                _logger.Info($"玩家 {player.Name} 得分更新: {player.Score}");
                this.SendEvent(new PlayerScoreUpdatedEvent { Player = player });
            },
            none: () => _logger.Warn($"玩家不存在: {playerId}")
        );
    }
}

示例 2：配置管理

public class ConfigurationSystem : AbstractSystem
{
    private readonly Dictionary<string, string> _config = new();

    public Option<string> GetConfig(string key)
    {
        return _config.TryGetValue(key, out var value)
            ? Option<string>.Some(value)
            : Option<string>.None;
    }

    public Option<int> GetIntConfig(string key)
    {
        return GetConfig(key)
            .Bind(value => int.TryParse(value, out var result)
                ? Option<int>.Some(result)
                : Option<int>.None);
    }

    public Option<bool> GetBoolConfig(string key)
    {
        return GetConfig(key)
            .Bind(value => bool.TryParse(value, out var result)
                ? Option<bool>.Some(result)
                : Option<bool>.None);
    }

    public void ApplyGraphicsSettings()
    {
        var width = GetIntConfig("screen_width").GetOrElse(1920);
        var height = GetIntConfig("screen_height").GetOrElse(1080);
        var fullscreen = GetBoolConfig("fullscreen").GetOrElse(false);
        var vsync = GetBoolConfig("vsync").GetOrElse(true);

        ApplyScreenSettings(width, height, fullscreen, vsync);
    }
}

示例 3：物品查找

public class InventorySystem : AbstractSystem
{
    public Option<Item> FindItemById(string itemId)
    {
        var item = _items.FirstOrDefault(i => i.Id == itemId);
        return item != null ? Option<Item>.Some(item) : Option<Item>.None;
    }

    public Option<Item> FindItemByType(ItemType type)
    {
        var item = _items.FirstOrDefault(i => i.Type == type);
        return item != null ? Option<Item>.Some(item) : Option<Item>.None;
    }

    public Result<Item> UseItem(string itemId)
    {
        return FindItemById(itemId)
            .ToResult("物品不存在")
            .Bind(item => item.IsUsable
                ? Result<Item>.Success(item)
                : Result<Item>.Failure("物品不可使用"))
            .OnSuccess(item => {
                item.Use();
                _logger.Info($"使用物品: {item.Name}");
                this.SendEvent(new ItemUsedEvent { Item = item });
            });
    }
}

Option 与 Result 的转换

// Option 转 Result
var option = Option<int>.Some(42);
var result = option.ToResult("值不存在"); // Result<int>

// Result 转 Option（需要自定义扩展）
var result = Result<int>.Success(42);
var option = result.IsSuccess
    ? Option<int>.Some(result.Match(succ: v => v, fail: _ => 0))
    : Option<int>.None;

异常处理

何时使用异常

异常应该用于处理不可预期的错误和不可恢复的错误：

// ✅ 适合使用异常的场景
public class SaveSystem : AbstractSystem
{
    public async Task SaveGameAsync(SaveData data)
    {
        try
        {
            var json = JsonSerializer.Serialize(data);
            await File.WriteAllTextAsync(_savePath, json);
        }
        catch (UnauthorizedAccessException ex)
        {
            _logger.Fatal("没有写入权限", ex);
            throw new SaveSystemException("无法保存游戏：权限不足", ex);
        }
        catch (IOException ex)
        {
            _logger.Error("IO 错误", ex);
            throw new SaveSystemException("无法保存游戏：磁盘错误", ex);
        }
    }
}

// ❌ 不适合使用异常的场景
public class PlayerSystem : AbstractSystem
{
    // 不要用异常处理业务逻辑
    public void UpdatePlayerHealth(string playerId, int damage)
    {
        var player = FindPlayerById(playerId);
        if (player == null)
            throw new PlayerNotFoundException(playerId); // ❌ 应该用 Option 或 Result

        player.Health -= damage;
    }
}

自定义异常

创建有意义的异常类型：

// 基础游戏异常
public class GameException : Exception
{
    public string ErrorCode { get; }
    public Dictionary<string, object> Context { get; }

    public GameException(
        string message,
        string errorCode,
        Dictionary<string, object> context = null,
        Exception innerException = null)
        : base(message, innerException)
    {
        ErrorCode = errorCode;
        Context = context ?? new Dictionary<string, object>();
    }
}

// 存档系统异常
public class SaveSystemException : GameException
{
    public SaveSystemException(
        string message,
        Exception innerException = null)
        : base(message, "SAVE_ERROR", null, innerException)
    {
    }
}

// 网络异常
public class NetworkException : GameException
{
    public int StatusCode { get; }

    public NetworkException(
        string message,
        int statusCode,
        Exception innerException = null)
        : base(
            message,
            "NETWORK_ERROR",
            new Dictionary<string, object> { ["statusCode"] = statusCode },
            innerException)
    {
        StatusCode = statusCode;
    }
}

// 使用示例
public class NetworkSystem : AbstractSystem
{
    public async Task<PlayerData> FetchPlayerDataAsync(string playerId)
    {
        try
        {
            var response = await _httpClient.GetAsync($"/api/players/{playerId}");

            if (!response.IsSuccessStatusCode)
            {
                throw new NetworkException(
                    $"获取玩家数据失败: {playerId}",
                    (int)response.StatusCode
                );
            }

            var json = await response.Content.ReadAsStringAsync();
            return JsonSerializer.Deserialize<PlayerData>(json);
        }
        catch (HttpRequestException ex)
        {
            _logger.Error($"网络请求失败: {playerId}", ex);
            throw new NetworkException("网络连接失败", 0, ex);
        }
    }
}

异常处理最佳实践

1. 捕获具体的异常类型

// ✅ 好的做法
try
{
    var data = await LoadDataAsync();
}
catch (FileNotFoundException ex)
{
    _logger.Warn("文件不存在", ex);
    return GetDefaultData();
}
catch (JsonException ex)
{
    _logger.Error("JSON 解析失败", ex);
    throw new DataException("数据格式错误", ex);
}
catch (IOException ex)
{
    _logger.Error("IO 错误", ex);
    throw new DataException("读取数据失败", ex);
}

// ❌ 避免：捕获所有异常
try
{
    var data = await LoadDataAsync();
}
catch (Exception ex) // 太宽泛
{
    _logger.Error("加载失败", ex);
    return null;
}

2. 不要吞掉异常

// ❌ 避免：吞掉异常
try
{
    RiskyOperation();
}
catch (Exception ex)
{
    // 什么都不做，异常被吞掉了
}

// ✅ 好的做法：记录并重新抛出或处理
try
{
    RiskyOperation();
}
catch (Exception ex)
{
    _logger.Error("操作失败", ex);
    throw; // 重新抛出原始异常
}

3. 使用 finally 清理资源

// ✅ 好的做法
FileStream stream = null;
try
{
    stream = File.OpenRead(path);
    // 处理文件
}
catch (IOException ex)
{
    _logger.Error("文件读取失败", ex);
    throw;
}
finally
{
    stream?.Dispose(); // 确保资源被释放
}

// 更好的做法：使用 using 语句
using (var stream = File.OpenRead(path))
{
    // 处理文件
} // 自动释放资源

日志记录

日志级别

GFramework 提供多个日志级别，根据错误严重程度选择合适的级别：

// Trace：详细的调试信息
_logger.Trace("进入 ProcessInput 方法");

// Debug：调试信息
_logger.Debug($"玩家位置: {player.Position}");

// Info：一般信息
_logger.Info("游戏启动成功");

// Warning：警告信息
_logger.Warn("配置文件不存在，使用默认配置");

// Error：错误信息
_logger.Error("保存游戏失败", exception);

// Fatal：致命错误
_logger.Fatal("无法初始化渲染系统", exception);

结构化日志

使用结构化日志记录上下文信息：

// 记录带上下文的日志
_logger.Log(
    LogLevel.Error,
    "玩家操作失败",
    ("playerId", playerId),
    ("action", "attack"),
    ("targetId", targetId),
    ("timestamp", DateTime.UtcNow)
);

// 记录带异常的结构化日志
_logger.Log(
    LogLevel.Error,
    "数据库操作失败",
    exception,
    ("operation", "insert"),
    ("table", "players"),
    ("retryCount", retryCount)
);

日志最佳实践

1. 记录足够的上下文

// ❌ 避免：信息不足
_logger.Error("操作失败");

// ✅ 好的做法：包含上下文
_logger.Error(
    $"保存玩家数据失败: PlayerId={playerId}, Reason={ex.Message}",
    ex
);

2. 不要记录敏感信息

// ❌ 避免：记录密码等敏感信息
_logger.Info($"用户登录: {username}, 密码: {password}");

// ✅ 好的做法：不记录敏感信息
_logger.Info($"用户登录: {username}");

3. 使用合适的日志级别

public class SaveSystem : AbstractSystem
{
    public async Task<Result<SaveData>> LoadSaveAsync(string saveId)
    {
        _logger.Debug($"开始加载存档: {saveId}");

        try
        {
            var data = await _storage.LoadAsync<SaveData>(saveId);

            if (data == null)
            {
                _logger.Warn($"存档不存在: {saveId}");
                return Result<SaveData>.Failure("存档不存在");
            }

            _logger.Info($"存档加载成功: {saveId}");
            return Result<SaveData>.Success(data);
        }
        catch (Exception ex)
        {
            _logger.Error($"加载存档失败: {saveId}", ex);
            return Result<SaveData>.Failure(ex);
        }
    }
}

用户反馈

友好的错误提示

将技术错误转换为用户友好的消息：

public class ErrorMessageService
{
    private readonly Dictionary<string, string> _errorMessages = new()
    {
        ["NETWORK_ERROR"] = "网络连接失败，请检查网络设置",
        ["SAVE_ERROR"] = "保存失败，请确保有足够的磁盘空间",
        ["INVALID_INPUT"] = "输入无效，请检查后重试",
        ["PERMISSION_DENIED"] = "权限不足，无法执行此操作",
        ["RESOURCE_NOT_FOUND"] = "资源不存在",
        ["TIMEOUT"] = "操作超时，请稍后重试"
    };

    public string GetUserFriendlyMessage(string errorCode)
    {
        return _errorMessages.TryGetValue(errorCode, out var message)
            ? message
            : "发生未知错误，请联系技术支持";
    }

    public string GetUserFriendlyMessage(Exception ex)
    {
        return ex switch
        {
            GameException gameEx => GetUserFriendlyMessage(gameEx.ErrorCode),
            FileNotFoundException => "文件不存在",
            UnauthorizedAccessException => "权限不足",
            TimeoutException => "操作超时",
            _ => "发生未知错误"
        };
    }
}

错误提示 UI

public class ErrorNotificationSystem : AbstractSystem
{
    private readonly ErrorMessageService _messageService;

    protected override void OnInit()
    {
        this.RegisterEvent<ErrorOccurredEvent>(OnErrorOccurred);
    }

    private void OnErrorOccurred(ErrorOccurredEvent e)
    {
        var userMessage = _messageService.GetUserFriendlyMessage(e.Exception);

        // 根据错误严重程度显示不同的 UI
        if (e.Exception is GameException gameEx)
        {
            switch (gameEx.ErrorCode)
            {
                case "NETWORK_ERROR":
                    ShowNetworkErrorDialog(userMessage);
                    break;

                case "SAVE_ERROR":
                    ShowSaveErrorDialog(userMessage);
                    break;

                default:
                    ShowGenericErrorToast(userMessage);
                    break;
            }
        }
        else
        {
            ShowGenericErrorDialog(userMessage);
        }
    }

    private void ShowNetworkErrorDialog(string message)
    {
        this.SendEvent(new ShowDialogEvent
        {
            Title = "网络错误",
            Message = message,
            Buttons = new[] { "重试", "取消" },
            OnButtonClicked = buttonIndex =>
            {
                if (buttonIndex == 0) // 重试
                {
                    this.SendEvent(new RetryNetworkOperationEvent());
                }
            }
        });
    }

    private void ShowSaveErrorDialog(string message)
    {
        this.SendEvent(new ShowDialogEvent
        {
            Title = "保存失败",
            Message = message,
            Buttons = new[] { "确定" }
        });
    }

    private void ShowGenericErrorToast(string message)
    {
        this.SendEvent(new ShowToastEvent
        {
            Message = message,
            Duration = 3000
        });
    }

    private void ShowGenericErrorDialog(string message)
    {
        this.SendEvent(new ShowDialogEvent
        {
            Title = "错误",
            Message = message,
            Buttons = new[] { "确定" }
        });
    }
}

错误恢复

重试机制

实现自动重试策略：

public class RetryPolicy
{
    public int MaxRetries { get; set; } = 3;
    public TimeSpan InitialDelay { get; set; } = TimeSpan.FromSeconds(1);
    public double BackoffMultiplier { get; set; } = 2.0;

    public async Task<Result<T>> ExecuteAsync<T>(
        Func<Task<T>> operation,
        Func<Exception, bool> shouldRetry = null)
    {
        var delay = InitialDelay;
        Exception lastException = null;

        for (int attempt = 0; attempt <= MaxRetries; attempt++)
        {
            try
            {
                var result = await operation();
                return Result<T>.Success(result);
            }
            catch (Exception ex)
            {
                lastException = ex;

                // 检查是否应该重试
                if (shouldRetry != null && !shouldRetry(ex))
                {
                    break;
                }

                // 最后一次尝试失败
                if (attempt == MaxRetries)
                {
                    break;
                }

                // 等待后重试
                await Task.Delay(delay);
                delay = TimeSpan.FromMilliseconds(delay.TotalMilliseconds * BackoffMultiplier);
            }
        }

        return Result<T>.Failure(lastException);
    }
}

// 使用示例
public class NetworkSystem : AbstractSystem
{
    private readonly RetryPolicy _retryPolicy = new()
    {
        MaxRetries = 3,
        InitialDelay = TimeSpan.FromSeconds(1),
        BackoffMultiplier = 2.0
    };

    public async Task<Result<PlayerData>> FetchPlayerDataAsync(string playerId)
    {
        return await _retryPolicy.ExecuteAsync(
            operation: async () =>
            {
                var response = await _httpClient.GetAsync($"/api/players/{playerId}");
                response.EnsureSuccessStatusCode();
                var json = await response.Content.ReadAsStringAsync();
                return JsonSerializer.Deserialize<PlayerData>(json);
            },
            shouldRetry: ex => ex is HttpRequestException || ex is TimeoutException
        );
    }
}

降级策略

提供多级降级方案：

public class ConfigurationSystem : AbstractSystem
{
    public async Task<GameConfig> LoadConfigAsync()
    {
        // 1. 尝试从远程服务器加载
        var remoteResult = await TryLoadFromRemoteAsync();
        if (remoteResult.IsSuccess)
        {
            _logger.Info("从远程服务器加载配置成功");
            await CacheConfigAsync(remoteResult.Match(succ: c => c, fail: _ => null));
            return remoteResult.Match(succ: c => c, fail: _ => null);
        }

        _logger.Warn($"远程加载失败: {remoteResult.Exception.Message}");

        // 2. 尝试从本地缓存加载
        var cacheResult = await TryLoadFromCacheAsync();
        if (cacheResult.IsSuccess)
        {
            _logger.Info("从本地缓存加载配置成功");
            return cacheResult.Match(succ: c => c, fail: _ => null);
        }

        _logger.Warn($"缓存加载失败: {cacheResult.Exception.Message}");

        // 3. 使用内置默认配置
        _logger.Error("所有配置源加载失败，使用默认配置");
        return GetDefaultConfig();
    }

    private async Task<Result<GameConfig>> TryLoadFromRemoteAsync()
    {
        try
        {
            var response = await _httpClient.GetAsync("/api/config");
            response.EnsureSuccessStatusCode();
            var json = await response.Content.ReadAsStringAsync();
            var config = JsonSerializer.Deserialize<GameConfig>(json);
            return Result<GameConfig>.Success(config);
        }
        catch (Exception ex)
        {
            return Result<GameConfig>.Failure(ex);
        }
    }

    private async Task<Result<GameConfig>> TryLoadFromCacheAsync()
    {
        try
        {
            var json = await File.ReadAllTextAsync(_cachePath);
            var config = JsonSerializer.Deserialize<GameConfig>(json);
            return Result<GameConfig>.Success(config);
        }
        catch (Exception ex)
        {
            return Result<GameConfig>.Failure(ex);
        }
    }

    private async Task CacheConfigAsync(GameConfig config)
    {
        try
        {
            var json = JsonSerializer.Serialize(config);
            await File.WriteAllTextAsync(_cachePath, json);
        }
        catch (Exception ex)
        {
            _logger.Warn("缓存配置失败", ex);
        }
    }

    private GameConfig GetDefaultConfig()
    {
        return new GameConfig
        {
            ServerUrl = "https://default.example.com",
            Timeout = 30,
            MaxRetries = 3
        };
    }
}

断路器模式

防止级联失败：

public class CircuitBreaker
{
    private int _failureCount = 0;
    private DateTime _lastFailureTime = DateTime.MinValue;
    private CircuitState _state = CircuitState.Closed;

    public int FailureThreshold { get; set; } = 5;
    public TimeSpan OpenDuration { get; set; } = TimeSpan.FromMinutes(1);

    public async Task<Result<T>> ExecuteAsync<T>(Func<Task<T>> operation)
    {
        // 检查断路器状态
        if (_state == CircuitState.Open)
        {
            if (DateTime.UtcNow - _lastFailureTime > OpenDuration)
            {
                _state = CircuitState.HalfOpen;
            }
            else
            {
                return Result<T>.Failure("断路器已打开，操作被拒绝");
            }
        }

        try
        {
            var result = await operation();

            // 成功，重置计数器
            if (_state == CircuitState.HalfOpen)
            {
                _state = CircuitState.Closed;
            }
            _failureCount = 0;

            return Result<T>.Success(result);
        }
        catch (Exception ex)
        {
            _failureCount++;
            _lastFailureTime = DateTime.UtcNow;

            // 达到阈值，打开断路器
            if (_failureCount >= FailureThreshold)
            {
                _state = CircuitState.Open;
            }

            return Result<T>.Failure(ex);
        }
    }

    private enum CircuitState
    {
        Closed,   // 正常状态
        Open,     // 断路器打开，拒绝请求
        HalfOpen  // 半开状态，尝试恢复
    }
}