ASP.NET webapi odata put，属性“ID”是对象关键信息的一部分，不能修改

Question

我是 ASP.NET webapi 的菜鸟，这是一个非常简单的情况，我陷入了困境。

我正在使用 webapi+odata

我的模特：

public class CategoryModel
{
    public int ID { get; set; }
    public string Name { get; set; }
    public int ParentID { get; set; }
}

我的自动生成控制器的 put 方法：

public async Task<IHttpActionResult> Put([FromODataUri] int key, Delta<CategoryModel> patch)
{
    Validate(patch.GetEntity());

    if (!ModelState.IsValid)
    {
        return BadRequest(ModelState);
    }

    CategoryModel categoryModel = await db.Category.FindAsync(key);
    if (categoryModel == null)
    {
        return NotFound();
    }

    patch.Put(categoryModel);

    try
    {
        await db.SaveChangesAsync();
    }
    catch (DbUpdateConcurrencyException)
    {
        if (!CategoryModelExists(key))
        {
            return NotFound();
        }
        else
        {
            throw;
        }
    }

    return Updated(categoryModel);
}

还有我的 jquery ajax

jQuery.ajax(
        {
          url       : '/api/Category(3)',
          data      : { Name:'New Category' },
          method    : 'PUT',
          headers   : {
            Accept        : 'application/json',
          },
          statusCode: {
            401: () => {
              console.log('handle the unautherized here');
            },
          },
          beforeSend: (jqXHR, settings) => {},
          error     : (jqXHR, textStatus, errorThrown) => {
            //TODO do some global error reporting

            Util.Error(JSON.parse(jqXHR.responseText));
            resolve(null);
          },
          success   : (data, textStatus, jqXHR) => {
            resolve(data);
          },
          complete  : (jqXHR, textStatus) => {}
        }
      );

和错误：

{
  "odata.error": {
    "code": "",
    "message": {
      "lang": "en-US",
      "value": "An error has occurred."
    },
    "innererror": {
      "message": "The property 'ID' is part of the object's key information and cannot be modified. ",
      "type": "System.InvalidOperationException",
      "stacktrace": "   at System.Data.Entity.Core.Objects.EntityEntry.DetectChangesInProperty(Int32 ordinal, Boolean detectOnlyComplexProperties, Boolean detectOnly)\r\n   at System.Data.Entity.Core.Objects.EntityEntry.DetectChangesInProperties(Boolean detectOnlyComplexProperties)\r\n   at System.Data.Entity.Core.Objects.ObjectStateManager.DetectChangesInScalarAndComplexProperties(IList`1 entries)\r\n   at System.Data.Entity.Core.Objects.ObjectStateManager.DetectChanges()\r\n   at System.Data.Entity.Core.Objects.ObjectContext.DetectChanges()\r\n   at System.Data.Entity.Internal.InternalContext.DetectChanges(Boolean force)\r\n   at System.Data.Entity.Internal.InternalContext.GetStateEntries(Func`2 predicate)\r\n   at System.Data.Entity.Internal.InternalContext.GetStateEntries()\r\n   at System.Data.Entity.Infrastructure.DbChangeTracker.Entries()\r\n   at System.Data.Entity.DbContext.GetValidationErrors()\r\n   at System.Data.Entity.Internal.InternalContext.SaveChangesAsync(CancellationToken cancellationToken)\r\n   at System.Data.Entity.Internal.LazyInternalContext.SaveChangesAsync(CancellationToken cancellationToken)\r\n   at System.Data.Entity.DbContext.SaveChangesAsync(CancellationToken cancellationToken)\r\n   at System.Data.Entity.DbContext.SaveChangesAsync()\r\n   at Notifier.Controllers.CategoryController.<Put>d__3.MoveNext() in E:\\csharp\\notifier\\Notifier\\Notifier\\Controllers\\CategoryController.cs:line 66\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at System.Threading.Tasks.TaskHelpersExtensions.<CastToObject>d__3`1.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at System.Web.Http.Controllers.ApiControllerActionInvoker.<InvokeActionAsyncCore>d__0.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at System.Web.Http.Controllers.ActionFilterResult.<ExecuteAsync>d__2.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at System.Web.Http.Dispatcher.HttpControllerDispatcher.<SendAsync>d__1.MoveNext()"
    }

GET 和 POST 工作正常，但 PUT 和 PATCH 给我这个错误。

请帮帮我...

更新：问题在于这个控制器使用 odata v3 生成的代码，我检查了普通的 webapi 控制器，它工作得很好，所以....

Answer 1

在我看来，您正在尝试更新一个 ID 不同于 3 的对象，但是您的 ajax 调用正在发送您在该行中硬编码的 Id = 3：

url       : '/api/Category(3)',