c# - EntityFramework 通用存储库，多个包含？

Question

我正在尝试从我的通用存储库更改我的通用检索方法。但我想为 includeproperties 传递一个字符串，以传递这个:params Expression<Func<TEntity, object>>[] includeProperties = null问题是当我调用这个方法时:

public virtual IEnumerable<TEntity> Retrieve(Expression<Func<TEntity, bool>> filter = null, params Expression<Func<TEntity, object>>[] includeProperties = null)

我想要例如:TEntityExample.Retrieve(filter: c=>c.Id=Id, includeProperties:c=> c.propertynav1, e=> e.propertynav1.propertynav3, e=> e.Prop4)

或者只是如果不需要导航属性TEntityExample.Retrieve(filter: c=>c.Id=Id)

但不知道为什么 includeProperties:不工作，不被接受，任何人都知道为什么，或者如果我做错了什么。我希望有可能不通过 includeProperties 或通过指定 includeProperties: 来传递它

public virtual IEnumerable<TEntity> Retrieve(Expression<Func<TEntity, bool>> filter = null, string includeProperties = "")
            {
                IQueryable<TEntity> query = _dbSet;

                if (filter != null)
                {
                    query = query.Where(filter);
                }

                if (!string.IsNullOrEmpty(includeProperties))
                {
                    foreach (var includeProperty in includeProperties.Split
                        (new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries))
                    {
                        query = query.Include(includeProperty);
                    }
                }
                return query.ToList();
            }

Answer 1

我做了类似的事情，但使用表达式来急切加载。也许这会有所帮助:

    public TEntity Item(Expression<Func<TEntity, bool>> wherePredicate, params Expression<Func<TEntity, object>>[] includeProperties)
    {
        foreach (var property in includeProperties)
        {
            _dbSet.Include(property);
        }
        return _dbSet.Where(wherePredicate).FirstOrDefault();
    }