abp getAll（）方法第一次出错

Question

Abp在linq中使用_xxxxRepository.GetAll()方法，ef，第一次出现问题，代码非常简单，第一次没问题。

  

System.InvalidOperationException：变量＆＃39; context＆＃39;类型   ＆＃39; Abp.EntityFrameworkCore.AbpDbContext＆＃39;引用范围＆＃39;＆＃39;，但是   它没有定义。

代码：

var query = from a in _docmentBorrowRepository.GetAll()
                    join c in _docmentRepository.GetAll() on a.DocmentId 
                    equals c.Id
                    join b in _abpDictionaryRepository.GetAll() on 
                    c.Type equals b.Id
                    select new DocmentBorrowListDto()
                    {
                        CreationTime = a.CreationTime,
                        Attr = c.Attr,
                        Attr_Name = c.Attr.ToString(),
                        Id = a.Id,
                        Location = c.Location,
                        Name = c.Name,
                        No = c.No,
                        Type = c.Type,
                        Type_Name = b.Title,
                        UserId = a.CreatorUserId,
                        Status = a.Status,
                        Des=a.Des
                    };
if (string.IsNullOrWhiteSpace(input.SearchKey) == false)
{
    query = query.Where(ite => ite.Name.Contains(input.SearchKey)||ite.No.Contains(input.SearchKey));
}
if (input.Type.HasValue)
{
    query = query.Where(ite => ite.Type == input.Type);
}
if (input.Attr.HasValue)
{
    query = query.Where(ite => ite.Attr == input.Attr);
}
switch (input.BorrowType) {
    case BorrowType.????:
        query = query.Where(ite => ite.UserId == AbpSession.UserId.Value);
        break;
    case BorrowType.????:
        query = query.Where(ite => ite.Status==-1||ite.Status==3);
        break;
    case BorrowType.?????:
        query = query.Where(ite => ite.Status ==2);
        break;
    case BorrowType.????:
        query = query.Where(ite => ite.Status == 1);
        break;
}
var count = query.Count();
var ret = (await query.OrderByDescending(r => r.CreationTime).PageBy(input).ToListAsync()).MapTo<List<DocmentBorrowListDto>>();