我在缺少引用的情况下调用 .Net Core 中的上下文时出错

Question

我似乎无法理解为什么我的方法在最底层有错误。

我有下面这两种方法，效果很好。

    public async Task<Claim> GetClaim(string id)
    {
        var query = _context.Claims.AsQueryable();
        var claim = await query.FirstOrDefaultAsync(c => c.ClaimNumber == id);
        return claim;
    }

    public async Task<IEnumerable<Message>> GetMessageThread(int userId, int recipientId)
    {
        var messages = await _context.Messages
            .Include(u => u.Sender).ThenInclude(p => p.Photos)
            .Include(u => u.Recipient).ThenInclude(p => p.Photos)
            .Where(m => m.RecipientId == userId && m.RecipientDeleted == false 
                && m.SenderId == recipientId 
                || m.RecipientId == recipientId && m.SenderId == userId 
                && m.SenderDeleted == false)
            .OrderByDescending(m => m.MessageSent)
            .ToListAsync();

        return messages;
    }

但是用这种方法我在第一行下得到两个红色错误，最后

'DbSet' does not contain a definition for 'GetAwaiter' and no accessible extension method 'GetAwaiter' accepting a first argument of type 'DbSet' could be found

和

Task> results Cannot implicitly convert type 'System.Threading.Tasks.Task>' to 'System.Collections.Generic.IEnumerable'. An explicit conversion exists

方法在这里

    public async Task<IEnumerable<Claim>> GetClaims(GetClaimsDto claimParams)
    {
        var claims = await _context.Claims;

        if (claimParams.MatterNumber != null) {
            claims = claims.Where(c => c.MatterNumber == claimParams.MatterNumber);
        }

        if (claimParams.FirstName != String.Empty) {
            claims = claims.Where(c => EF.Functions.Like(c.FirstName, "%" + claimParams.FirstName + "%"));
        }

        if (claimParams.LastName != String.Empty) {
            claims = claims.Where(c => EF.Functions.Like(c.LastName, "%" + claimParams.LastName + "%"));
        }

        var results = claims.OrderByDescending(m => m.MatterNumber).ToListAsync();

        return results;
    }

这是我的声明实体：

public class Claim
{
    public int Id { get; set; }
    public string ClaimNumber { get; set; }
    public string MatterNumber { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string Data { get; set; }
    [NotMapped]
    public string[] Errors { get; set; }
    [NotMapped]
    public List<string>  SearchResults { get; set; }
    public DateTime CreatedDate { get; set; }
    public string CreatedBy { get; set; }
    public DateTime EditedDate { get; set; }
    public string EditedBy { get; set; }  
}

这里是错误

Answer 1

_context.Claims 不是异步的，因此您不需要等待它。

.ToListAsync() 是异步的，因此您需要等待它。

试试这个。

    public async Task<IEnumerable<Claim>> GetClaims(GetClaimsDto claimParams)
    {
        var claims = _context.Claims;

        if (claimParams.MatterNumber != null) {
            claims = claims.Where(c => c.MatterNumber == claimParams.MatterNumber);
        }

        if (claimParams.FirstName != String.Empty) {
            claims = claims.Where(c => EF.Functions.Like(c.FirstName, "%" + claimParams.FirstName + "%"));
        }

        if (claimParams.LastName != String.Empty) {
            claims = claims.Where(c => EF.Functions.Like(c.LastName, "%" + claimParams.LastName + "%"));
        }

        var results = await claims.OrderByDescending(m => m.MatterNumber).ToListAsync();

        return results;
    }

我在缺少引用的情况下调用 .Net Core 中的上下文时出错

Errors wih my call to context in .Net Core with missing reference

c#

linq-to-entities

entity-framework

.net-core