一起使用存储库工厂和存储库因子设计模式

Question

我的 DbRepository 类如下：

public class DbRepository<TEntity, TDbContext> : IRepository<TEntity>
    where TEntity : class, IEntity
    where TDbContext : DbContext
{
    protected readonly TDbContext dbContext;

    /// <summary>
    ///     Initializes a new instance of the <see cref="DbRepository{TEntity}" /> class.
    /// </summary>
    public DbRepository(TDbContext dbContext)
    {
        this.dbContext = dbContext;
    }

    /// <inheritdoc/>
    public async Task<TEntity> AddAsync(TEntity entity)
    {
        ObjectCheck.EntityCheck(entity, $"{nameof(TEntity)} missing.");
        await dbContext.Set<TEntity>().AddAsync(entity);
        await dbContext.SaveChangesAsync();
        return entity;
    }

    /// <inheritdoc/>
    public virtual async Task<TEntity> GetAsync(object primaryKey)
    {
        ObjectCheck.PrimaryKeyCheck(primaryKey, $"primaryKey <= 0 in {nameof(IRepository<TEntity>)}");
        return await dbContext.Set<TEntity>().FindAsync(primaryKey);
    }

    /// <inheritdoc/>
    public virtual IQueryable<TEntity> GetAll(Expression<Func<TEntity, bool>> filter = null)
    {
        return (filter != null ? dbContext.Set<TEntity>().Where(filter) : dbContext.Set<TEntity>());
    }

    /// <inheritdoc/>
    public virtual async Task<TEntity> GetSingleAsync(Expression<Func<TEntity, bool>> filter)
    {
        return await dbContext.Set<TEntity>().SingleOrDefaultAsync(filter);
    }

    /// <inheritdoc/>
    public virtual async Task<TEntity> UpdateAsync(TEntity entity)
    {
        ObjectCheck.EntityCheck(entity, $"{nameof(TEntity)} missing.");
        dbContext.Set<TEntity>().Update(entity);
        await dbContext.SaveChangesAsync();
        return entity;
    }

    /// <inheritdoc/>
    public virtual async Task DeleteAsync(object primaryKey)
    {
        var entityToBeDeleted = await GetAsync(primaryKey);
        ObjectCheck.EntityCheck(entityToBeDeleted, $"{nameof(TEntity)} missing.");

        dbContext.Set<TEntity>().Remove(entityToBeDeleted);
        await dbContext.SaveChangesAsync();
    }

}

我的界面如下：

   public interface IRepository<TEntity>
      where TEntity : class, IEntity
   {
    Task<TEntity> GetAsync(object primaryKey);

    IQueryable<TEntity> GetAll(Expression<Func<TEntity, bool>> filter = null);

    Task<TEntity> GetSingleAsync(Expression<Func<TEntity, bool>> filter);

    Task<TEntity> AddAsync(TEntity entity);

    Task<TEntity> UpdateAsync(TEntity entity);

    Task DeleteAsync(object primaryKey);
   }
    

如何在启动时将它们注册为作用域并告诉每个类创建存储库？那么我可以在这些存储库上编写测试吗？

我有 4 个模型，我不想为每个模型创建存储库类和接口它们总是相同的 - 简单的 crud 操作。相反，我希望工厂创建它们。

public class RepositoryFactory
    {
        public static TRepository GetRepositoryInstance<T, TRepository>()
         where TRepository : IRepository<T>, new()
        {
            return new TRepository();
        }
    }

我得到的错误是类型必须是引用类型才能在泛型类型或方法 IRepository 中用作参数 TEntity

Answer 1

它给你这个错误是因为在 IRepository 接口中你告诉 T 必须是一个类（引用类型）并且它必须实现 IEntity 接口。

在工厂里，你一个都没说。

可能你必须写这样的东西：

public class RepositoryFactory
{
    public static TRepository GetRepositoryInstance<T, TRepository>()
          where TRepository : IRepository<T>, new()
          where T : class, IEntity
    {
        return new TRepository();
    }
}