Question

我有一个控制器，其开头如下：

[Route("api/[controller]")]
public class PersonsController : BaseController

到目前为止，

BaseController看起来像这样：

public class BaseController : Controller
{
    public BaseController(CompanyDbContext dbContext)
    {
        Db = dbContext;
    }

    protected CompanyDbContext Db;
}

PersonsController有一些获取，一个帖子，一个放置和一个删除。除了Delete操作之外的所有操作都可以正常工作，解决注入的CompanyDbContext没有问题。

Delete操作如下所示：

[HttpDelete("{id}")]
public async Task<IActionResult> Delete(int id)
{
    var pers = await Db.Persons.SingleOrDefaultAsync(p => p.PersonId == id);
    if (pers == null)
    {
        return NotFound();
    }
    Db.Remove(pers);
    await Db.SaveChangesAsync();
    return Ok();
}

然而，当我执行删除请求时：

public async Task DeletePersonAsync(int id)
{
    var resp = await _client.DeleteAsync($"api/Persons/{id}");
    resp.EnsureSuccessStatusCode();
}

其中_client是HttpClient，我收到以下错误：

InvalidOperationException：无法解析类型的服务＆＃39; AcmeSoft.Api.Data.CompanyDbContext＆＃39;在尝试激活时＆＃39; AcmeSoft.Api.Controllers.PersonsController＆＃39;

我使用的是默认的内置DI，它带有一个新的MVC Core 2.0项目。我在类Startup中注册了上下文服务，如下所示：

public void ConfigureServices(IServiceCollection services)
{
    services.AddDbContext<CompanyDbContext>(options =>
        options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection")));
    services.AddMvc();
}

然而，除Delete之外，所有操作的服务都能正常解析。这可能有什么问题？我哪里出错？

对于喜欢长问题的人，整个PersonsController如下：

[Route("api/[controller]")]
public class PersonsController : BaseController
{
    public PersonsController(CompanyDbContext dbContext) : base(dbContext)
    {
    }

    [HttpGet]
    public IActionResult Get()
    {
        var persons = Db.Persons.ToList();
        return Ok(persons);
    }

    [HttpGet("{id}")]
    public async Task<IActionResult> Get(int id)
    {
        var pers = await Db.Persons.SingleOrDefaultAsync(p => p.PersonId == id);
        if (pers == null)
        {
            return Ok(null);
        }
        return Ok(pers);
    }

    [HttpGet("GetByIdNumber/{idNumber}")]
    public async Task<IActionResult> GetByIdNumber(string idNumber)
    {
        var pers = await Db.Persons.SingleOrDefaultAsync(e => e.IdNumber == idNumber);
        if (pers == null)
        {
            return Ok(null);
        }

        return Ok(pers);
    }

    [HttpGet("PersonEmployees")]
    public async Task<IActionResult> PersonEmployees()
    {
        var emps = await Db.PersonEmployees.ToListAsync();
        return Ok(emps);
    }

    [HttpPost]
    public async Task<IActionResult> Post([FromBody] Person person)
    {
        Db.Add(person);
        await Db.SaveChangesAsync();
        return Ok(person);
    }

    [HttpPut]
    public async Task<IActionResult> Put([FromBody] Person person)
    {
        Db.Update(person);
        await Db.SaveChangesAsync();
        return Ok(person);
    }

    [HttpDelete("{id}")]
    public async Task<IActionResult> Delete(int id)
    {
        var pers = await Db.Persons.SingleOrDefaultAsync(p => p.PersonId == id);
        if (pers == null)
        {
            return NotFound();
        }
        Db.Remove(pers);
        await Db.SaveChangesAsync();
        return Ok();
    }
}

除删除工作以外的所有操作。

ADDED：开发人员错误页面上显示的堆栈跟踪是：

System.InvalidOperationException: Unable to resolve service for type 'AcmeSoft.Api.Data.CompanyDbContext' while attempting to activate 'AcmeSoft.Api.Controllers.PersonsController'.
   at Microsoft.Extensions.Internal.ActivatorUtilities.GetService(IServiceProvider sp, Type type, Type requiredBy, Boolean isDefaultParameterRequired)
   at lambda_method(Closure , IServiceProvider , Object[] )
   at Microsoft.AspNetCore.Mvc.Controllers.ControllerActivatorProvider.<>c__DisplayClass4_0.<CreateActivator>b__0(ControllerContext controllerContext)
   at Microsoft.AspNetCore.Mvc.Controllers.ControllerFactoryProvider.<>c__DisplayClass5_0.<CreateControllerFactory>g__CreateController|0(ControllerContext controllerContext)
   at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.<InvokeInnerFilterAsync>d__14.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.<InvokeNextResourceFilter>d__22.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.Rethrow(ResourceExecutedContext context)
   at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.<InvokeFilterPipelineAsync>d__17.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.<InvokeAsync>d__15.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.AspNetCore.Builder.RouterMiddleware.<Invoke>d__4.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.<Invoke>d__7.MoveNext()

注入的服务仅针对删除操作

0 个答案: