一个上下文同时跟踪两个相同的实体

[cc3w]

Description

在更新前将实体的状态设置为Detached再更新，不报错，但是数据库没有更新。另说明还有一种情况，当结合Masa blazor时，在前端页面同时更新同一条记录也是会报同样的错误。但是单纯使用swagger测试并不会。
参考代码如下：
public async Task GetGenerateCodeAsync(AllMapTable mapTable)
{
Guid? tid = null;
//自动插入mapTable表
var table = await _mapTableRepository.FindAsync(t => t.EnTableName.Equals(mapTable));
if (table == null)
{
var description = EnumDescription.GetDescriptionAttribute(mapTable);
if (description == null)
{
throw new UserFriendlyException("获取枚举上的Description失败");
}
var command = new CreateMapTableCommand(description, mapTable.ToString());
await _eventBus.PublishAsync(command);
tid = command.Id;
}
await _codingRuleInfoRepository.GenerateCode(mapTable);

    var tt = await _codingRuleInfoRepository.FindAsync(t => t.MapTableId == (Guid)tid);

    tt.CurrentValue = 5;

    await _codingRuleInfoRepository.UpdateAsync(tt);

    return "111";

}
报错如下：System.InvalidOperationException: The instance of entity type 'CodingRuleInfo' cannot be tracked because another instance with the same key value for {'Id'} is already being tracked. When attaching existing entities, ensure that only one entity instance with a given key value is attached. Consider using 'DbContextOptionsBuilder.EnableSensitiveDataLogging' to see the conflicting key values.

at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.IdentityMap1.ThrowIdentityConflict(InternalEntityEntry entry) at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.IdentityMap1.Add(TKey key, InternalEntityEntry entry, Boolean updateDuplicate)···

.NET version

No response

MASA Framework version

No response

[Qinyouzeng]

你好：
1、 你附加的源码尽量完整些，异常信息页尽量完整的贴出来；
2、 _在更新前将实体的状态设置为Detached再更新，不报错，但是数据库没有更新_这个问题，在代码里面没有反馈，也不好判断是哪里的问题；
3、_在前端页面同时更新同一条记录也是会报同样的错误。但是单纯使用swagger测试并不会_据此分析，应该跟你的服务对象周期使用有关，通过依赖关系注入进行参数绑定，IEventBus对象必须在接口方法上进行绑定（每次调用改接口，就会创建一次新的类型对象），不能在controller的构造方法里面绑定（此时绑定，该对象为应用程序存在期间一直存在的对象）。
这里得IEventBus对象注入，可以这么用

...

public Task AddAsync([FromServices] IEventBus eventBus, Dto dto)
{
      var command=new AddCommand(dto);
      return eventBus.PublishAsync(command);
}

...

[cc3w]

十分感谢您的解答！！
好的，下面是简化业务逻辑举个示例

[Route("/API/[controller]/[action]")]
[ApiController]
[Authorize]
public class CodingRuleInfoService : ControllerBase
{
    private readonly IEventBus _eventBus;
    private readonly ICodingRuleInfoRepository _codingRuleInfoRepository;
    private readonly IMapTableRepository _mapTableRepository;
 public CodingRuleInfoService(ICodingRuleInfoRepository codingRuleInfoRepository, IMapTableRepository mapTableRepository, IEventBus eventBus)
 {
     _codingRuleInfoRepository = codingRuleInfoRepository;
     _mapTableRepository = mapTableRepository;
     _eventBus = eventBus;
 }
     [HttpGet]
    [AllowAnonymous]
    public async Task<string> GetGenerateCodeAsync([FromServices] IEventBus eventBus, AllMapTable mapTable)
    {

        var description = EnumDescription.GetDescriptionAttribute(mapTable);
        var command = new CreateMapTableCommand(description, mapTable.ToString());
        await eventBus.PublishAsync(command);


        await _codingRuleInfoRepository.GenerateCode(mapTable);

        return "1111";
    }
}

一开始使用的是_eventBus，后来听了您的建议使用[FromServices] IEventBus eventBus，结果是一样的；
仓储接口层

public interface ICodingRuleInfoRepository : IRepository<CodingRuleInfo>
{
    /// <summary>
    /// 生成编码
    /// </summary>
    /// <param name="table"></param>
    /// <returns></returns>
    Task<string> GenerateCode(AllMapTable table);
}

仓储实现层

public class CodingRuleInfoRepository : Repository<PlatformDbContext, CodingRuleInfo>, ICodingRuleInfoRepository
{
    private readonly PlatformDbContext _PlatformDbContext;
    public CodingRuleInfoRepository(PlatformDbContext PlatformDbContext, IUnitOfWork unitOfWork, IRepository<MapTable> mapTableRepository) : base(PlatformDbContext, unitOfWork)
    {
        _PlatformDbContext = PlatformDbContext;
    }

    public async Task<string> GenerateCode(AllMapTable table)
    {

        var entity = await _PlatformDbContext.Set<MapTable>().FirstOrDefaultAsync(t => t.EnTableName.Equals(table.ToString()));

        //var entityKey = entity.GetKeys().First();
        //var existingEntity = _PlatformDbContext.ChangeTracker.Entries<MapTable>().FirstOrDefault(e =>
        //{
        //    var entity = e.Entity.GetKeys().First();
        //    return entity.Name.Equals(entityKey.Name) && entity.Value.Equals(entity.Value);

        //})?.Entity;
        //if (existingEntity != null)
        //{
        //    _PlatformDbContext.Entry(existingEntity).State = Microsoft.EntityFrameworkCore.EntityState.Detached;
        //}

        entity.Remark = "2222";
        _PlatformDbContext.Set<MapTable>().Update(entity);

        return "2222";
    }
}

仓储实现层注释的代码放开，不会报错，但是数据库没有更新Remark字段
报错如下：

System.InvalidOperationException: The instance of entity type 'MapTable' cannot be tracked because another instance with the same key value for {'Id'} is already being tracked. When attaching existing entities, ensure that only one entity instance with a given key value is attached. Consider using 'DbContextOptionsBuilder.EnableSensitiveDataLogging' to see the conflicting key values.
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.IdentityMap`1.ThrowIdentityConflict(InternalEntityEntry entry)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.IdentityMap`1.Add(TKey key, InternalEntityEntry entry, Boolean updateDuplicate)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.IdentityMap`1.Add(InternalEntityEntry entry)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.StartTracking(InternalEntityEntry entry)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.InternalEntityEntry.SetEntityState(EntityState oldState, EntityState newState, Boolean acceptChanges, Boolean modifyProperties)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.EntityGraphAttacher.PaintAction(EntityEntryGraphNode`1 node)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.EntityEntryGraphIterator.TraverseGraph[TState](EntityEntryGraphNode`1 node, Func`2 handleNode)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.EntityGraphAttacher.AttachGraph(InternalEntityEntry rootEntry, EntityState targetState, EntityState storeGeneratedWithKeySetTargetState, Boolean forceStateWhenUnknownKey)
   at Microsoft.EntityFrameworkCore.Internal.InternalDbSet`1.Update(TEntity entity)
   at MOM.Services.Platform.Infrastructure.Repositories.CodingModel.CodingRuleInfoRepository.GenerateCode(AllMapTable table) in D:\MyCC\codes\asuneast\MOM20241029\src\Services\MOM.Services.Platform\Infrastructure\Repositories\CodingModel\CodingRuleInfoRepository.cs:line 35
   at MOM.Services.Platform.Controllers.Setting.CodingRuleInfoService.GetGenerateCodeAsync(IEventBus eventBus, AllMapTable mapTable) in D:\MyCC\codes\asuneast\MOM20241029\src\Services\MOM.Services.Platform\Controllers\Setting\CodingRuleInfoService.cs:line 81
   at lambda_method112(Closure , Object )
   at Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.AwaitableObjectResultExecutor.Execute(IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeActionMethodAsync>g__Awaited|12_0(ControllerActionInvoker invoker, ValueTask`1 actionResultValueTask)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeNextActionFilterAsync>g__Awaited|10_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeInnerFilterAsync>g__Awaited|13_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeFilterPipelineAsync>g__Awaited|20_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
   at Microsoft.AspNetCore.Routing.EndpointMiddleware.<Invoke>g__AwaitRequestTask|6_0(Endpoint endpoint, Task requestTask, ILogger logger)
   at Microsoft.AspNetCore.Localization.RequestLocalizationMiddleware.Invoke(HttpContext context)
   at Masa.Contrib.Isolation.Middleware.IsolationMiddleware.InvokeAsync(HttpContext httpContext, IEnumerable`1 middlewares)
   at Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)
   at Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext context)
   at Swashbuckle.AspNetCore.SwaggerUI.SwaggerUIMiddleware.Invoke(HttpContext httpContext)
   at Swashbuckle.AspNetCore.Swagger.SwaggerMiddleware.Invoke(HttpContext httpContext, ISwaggerProvider swaggerProvider)
   at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)

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