在添加范围后，无法获取实体的密钥

Question

我尝试将IEnumerable添加到我的数据库中，然后在保存更改后获取其密钥（id）。 如果我只添加一个实体（没有集合），则在SaveChanges（）之后自动填充id，但是在集合中 - 这不起作用。

以下是存储库中的Add（OrUpdate）方法：

private void Add(IEnumerable<LabLineEntity> p_lines)
    {
        foreach (var line in p_lines)
        {
            line.isActive = true;
        }
//assume this gets a main-work from the context, all line are related to a specific work
        LabMainEntity labMain = GetSpecific<LabMainEntity>(p_lines.First().AssignedToWork);

        m_context.LabLines.AddRange(p_lines);

        foreach (var line in p_lines) // adds to the ICollection
        {
            labMain.Lines.Add(line);
        }
    }
public void AddOrUpdate(IEnumerable<LabLineEntity> p_labLines)
    {
        if (!LinesAreLegal(p_labLines))
        {
            throw new Exception("Lab lines are not legal!");
        }
        var newLabLines = p_labLines.Where(l => l.Id == Guid.Empty);
        var existingLabLines = p_labLines.Where(l => l.Id != Guid.Empty);
        LabMainEntity labMain = GetSpecific<LabMainEntity>(p_labLines.First().AssignedToWork);
        if (existingLabLines.Any())
        {
            HashSet<Guid> existingLineIds = new HashSet<Guid>(existingLabLines.Select(l => l.Id));
            // from all the lines in the main, select those that are NOT in the lines to update.
            // this will return the lines that should be removed!
            HashSet<Guid> linesToRemove = new HashSet<Guid>(labMain.Lines.Where(ell => !existingLineIds.Contains(ell.Id)).Select(t=>t.Id));
            foreach (var lineGuid in linesToRemove)
            {
                LabLineEntity lineInDb = GetSpecific<LabLineEntity>(lineGuid);
                m_context.LabLines.Remove(lineInDb);
                labMain.Lines.Remove(lineInDb);
            }
            Update(existingLabLines);
        }
        if (newLabLines.Any())
        {
            Add(newLabLines);
        }
    }

这是外线电话：

[HttpPost("")]
    public async Task<IActionResult> AddOrUpdateLabLine([FromBody] IEnumerable<LabLineEntityViewModel> p_labLinesVM)
    {
        if (!ModelState.IsValid)
        {
            return BadRequest(ModelState.ToString());
        }
        IEnumerable<LabLineEntity> labLinesE = m_mapper.ViewModelToModel(p_labLinesVM);
        try
        {
            m_repository.AddOrUpdate(labLinesE);
        }
        catch (Exception ex)
        {
            return BadRequest(ex.Message);
        }
        if (!(await m_repository.SaveChangesAsync()))
        {
            return BadRequest("Failed to save to the Database (ModelState was ok)");
        }
        List<LabLineEntity> labLinesToReturn = new List<LabLineEntity>();
        foreach (var labLine in labLinesE)
        {
//THIS IS NULL :(
            LabLineEntity lineToAdd = m_repository.GetSpecific<LabLineEntity>(labLine.Id);
            labLinesToReturn.Add(lineToAdd);
        }
        IEnumerable<LabLineEntityViewModel> returnedValue = m_mapper.ModelToViewModel(labLinesToReturn);
        return Created($"Modules/Lab/Forms/Main/", returnedValue);
    }

SaveChanges：

public async Task<bool> SaveChangesAsync()
    {
        int rowsChanged = 0;
        try
        {
            rowsChanged = await m_context.SaveChangesAsync();
        }
        catch (Exception)
        {
            // ignored
        }
        return rowsChanged > 0;
    }

在此方法之后，从外部函数（传递集合）调用SaveChanges（Async），但不填充ID。

任何解决方案？ 此致