DbContext Update 不起作用，但 Get 起作用。为什么？

Question

我在核心层实现了存储库和 UnitOfWork 模式：

public class Repository<TEntity, TContext> : UnitOfWork, IRepository<TEntity>
 where TEntity : class, new()
 where TContext : DbContext
{
    private readonly TContext _context;

    public Repository(TContext dbContext) : base(dbContext)
    {
        _context = dbContext;
    }

    public async Task<bool> AddAsync(TEntity model)
    {
        await _context.Set<TEntity>().AddAsync(model);
        return true;
    }

    public List<TEntity> Get()
    {
        return _context.Set<TEntity>().ToList();
    }

    public bool Remove(TEntity model)
    {
        _context.Set<TEntity>().Remove(model);
        return true;
    }

    public async Task<int> SaveAsync()
    {
        return await _context.SaveChangesAsync();
    }

    public bool Update(TEntity model)
    {
        _context.Set<TEntity>().Update(model);
        return true;
    }
}

和

public class UnitOfWork : IUnitOfWork
{
    private readonly DbContext _context;
    private readonly IDbContextTransaction _transaction;

    public UnitOfWork(DbContext context)
    {
        _context = context ?? throw new ArgumentNullException(nameof(context));
        _transaction = _context.Database.CurrentTransaction ?? _context.Database.BeginTransaction();
    }

    public async Task<bool> Commit(bool state = true)
    {
        try
        {
            await _context.SaveChangesAsync();

            if (state)
                _transaction.Commit();
            else
                _transaction.Rollback();

            return true;
        }
        catch (Exception)
        {
            _transaction.Rollback();
            throw; // Rethrow the exception after rolling back the transaction
        }
        finally
        {
            Dispose();
        }
    }

    public void Dispose()
    {
        Dispose(true);
        GC.SuppressFinalize(this);
    }

    protected virtual async void Dispose(bool disposing)
    {
        if (disposing)
        {
            await _context.DisposeAsync();
            _transaction.Dispose();
        }
    }
}

所以我在我的 DataAccess 和 BusinessLayer 中使用这个类，最后在我的 MVC 控制器中使用这个类，就像分层结构一样。当我调用 Get() 方法时我可以获取值。但我尝试通过 Update() 方法更改一个值，但没有成功。尽管我调用了 SaveAsync() 方法。

我正在下面分享我的数据访问和业务层。

数据访问：

public class ResponsibleDal : Repository<Responsible, TaskTracingDbContext>, IResponsibleDal
{
    public ResponsibleDal(TaskTracingDbContext dbContext) : base(dbContext)
    {

    }
}

数据访问工厂：

public class MainDal : IMainDal
{
    private readonly Lazy<IResponsibleDal> _responsibleDalLazy;

    public MainDal(IResponsibleDal responsibleDalLazy)
    {
        _responsibleDalLazy = new Lazy<IResponsibleDal>(() => responsibleDalLazy);
    }

    public IResponsibleDal ResponsibleDal => _responsibleDalLazy.Value;
}

业务：

public class ResponsibleBus : IResponsibleBus
{
    private readonly IMainDal _mainDal;

    public ResponsibleBus(IMainDal mainDal)
    {
        _mainDal = mainDal;
    }

    public async Task<bool> AddAsync(Responsible model)
    {
        return await _mainDal.ResponsibleDal.AddAsync(model);
    }

    public List<Responsible> Get()
    {
        return _mainDal.ResponsibleDal.Get();
    }

    public bool Remove(Responsible model)
    {
        return _mainDal.ResponsibleDal.Remove(model);
    }

    public Task<int> SaveAsync()
    {
        return _mainDal.ResponsibleDal.SaveAsync();
    }

    public Responsible? GetById(int id)
    {
        return _mainDal.ResponsibleDal.Get().Find(x => x.Id == id);
    }

    public Responsible? GetByIdentityNumber(string? identityNumber)
    {
        if (identityNumber is null)
            return null;
        return _mainDal.ResponsibleDal.Get().Find(x => x.IdentityNumber == identityNumber);
    }
    public bool Update(Responsible model)
    {
        return _mainDal.ResponsibleDal.Update(model);
    }
}

商业工厂：

public class MainBus : IMainBus
{
    private readonly Lazy<IResponsibleBus> _responsibleBusLazy;

    public MainBus(IResponsibleBus responsibleBusLazy)
    {
        _responsibleBusLazy = new Lazy<IResponsibleBus>(() => responsibleBusLazy);
    }

    public IResponsibleBus ResponsibleBus => _responsibleBusLazy.Value;
}

终于在我的控制器中：

var entity = _mainBus.ResponsibleBus.GetByIdentityNumber(model.UserName);

if (entity is not null)
{
    entity.ThemeSettings = model.Theme;
    _mainBus.ResponsibleBus.Update(entity);
    await _mainBus.ResponsibleBus.SaveAsync();

    HttpContext.Session.SetString("Theme", model.Theme.ToString());
}
else
{
    TempData["Error"] = "Kullanıcı veritabanında bulunamadı";
    return RedirectToAction(nameof(Index), model);
}

我还在 Program.cs 中这样定义了范围：

builder.Services.AddDbContext<TaskTracingDbContext>();

builder.Services.AddTransient<IResponsibleDal, ResponsibleDal>();
builder.Services.AddTransient(provider => new Lazy<IResponsibleDal>(provider.GetRequiredService<IResponsibleDal>()));

builder.Services.AddTransient<IResponsibleBus, ResponsibleBus>();
builder.Services.AddTransient(provider => new Lazy<IResponsibleBus>(provider.GetRequiredService<IResponsibleBus>()));


builder.Services.AddTransient<IMainDal, MainDal>();
builder.Services.AddTransient<IMainBus, MainBus>();

你能向我解释一下我不知道的细节吗？

Answer 1

我解决了。因为 Repository 类中的

SaveAsync()

方法。我必须调用

Commit()

类下的

UnitOfWork

方法。

Commit()

方法保存更改。

public async Task<bool> SaveAsync()
{
    return await Commit();
}