Asp.net core TempData gives 500 errors when adding a list and redirecting to another view

Question

I am trying to create a list of alerts and add them to TempData . But it works if I did not redirect. When I redirect, they give me 500 errors. I also set a breakpoint, but it didn’t hit when I redirected another wise one that he pressed correctly.

Actionmethod

 public IActionResult Create(CategoryCreateVM input) { if (ModelState.IsValid) { var category = mapper.Map<Categories>(input); categoryBL.Add(category); List<Alert> alert = new List<Alert>(); alert.Add(new Alert("alert-success", "success message")); alert.Add(new Alert("alert-danger", "danger message")); TempData["Alert"] = alert; return RedirectToAction("Index"); } return View(input); } 

As I see access.

 @{ var alerts = TempData["Alert"] as List<Alert>; } @if (alerts != null && alerts.Count > 0) { <div class=""> @foreach (var alert in alerts) { <div class="alert @alert.AlertClass alert-dismissible"> <button type="button" class="close" data-dismiss="alert" aria-hidden="true">&times;</button> @alert.Message </div> } </div> } 

Stack trace

  Exception thrown: 'System.InvalidOperationException' in Microsoft.AspNetCore.Mvc.ViewFeatures.dll Exception thrown: 'System.InvalidOperationException' in mscorlib.dll Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker: Information: Executed action MvcSandbox.Controllers.HomeController.Index (MvcSandbox) in 46.4619ms Exception thrown: 'System.InvalidOperationException' in mscorlib.dll Exception thrown: 'System.InvalidOperationException' in mscorlib.dll Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware: Error: An unhandled exception has occurred while executing the request System.InvalidOperationException: The 'Microsoft.AspNetCore.Mvc.ViewFeatures.Internal.TempDataSerializer' cannot serialize an object of type 'MvcSandbox.Controllers.Alert'. at Microsoft.AspNetCore.Mvc.ViewFeatures.Internal.TempDataSerializer.EnsureObjectCanBeSerialized(Object item) in D:\temp\Mvc-dev\src\Microsoft.AspNetCore.Mvc.ViewFeatures\Internal\TempDataSerializer.cs:line 207 at Microsoft.AspNetCore.Mvc.ViewFeatures.Internal.TempDataSerializer.Serialize(IDictionary`2 values) in D:\temp\Mvc-dev\src\Microsoft.AspNetCore.Mvc.ViewFeatures\Internal\TempDataSerializer.cs:line 142 at Microsoft.AspNetCore.Mvc.ViewFeatures.SessionStateTempDataProvider.SaveTempData(HttpContext context, IDictionary`2 values) in D:\temp\Mvc-dev\src\Microsoft.AspNetCore.Mvc.ViewFeatures\ViewFeatures\SessionStateTempDataProvider.cs:line 62 at Microsoft.AspNetCore.Mvc.ViewFeatures.TempDataDictionary.Save() in D:\temp\Mvc-dev\src\Microsoft.AspNetCore.Mvc.ViewFeatures\ViewFeatures\TempDataDictionary.cs:line 166 at Microsoft.AspNetCore.Mvc.ViewFeatures.Internal.SaveTempDataFilter.SaveTempData(IActionResult result, ITempDataDictionaryFactory factory, HttpContext httpContext) in D:\temp\Mvc-dev\src\Microsoft.AspNetCore.Mvc.ViewFeatures\Internal\SaveTempDataFilter.cs:line 91 at Microsoft.AspNetCore.Mvc.ViewFeatures.Internal.SaveTempDataFilter.OnResultExecuted(ResultExecutedContext context) in D:\temp\Mvc-dev\src\Microsoft.AspNetCore.Mvc.ViewFeatures\Internal\SaveTempDataFilter.cs:line 80 at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted) in D:\temp\Mvc-dev\src\Microsoft.AspNetCore.Mvc.Core\Internal\ControllerActionInvoker.cs:line 1023 at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.<InvokeNextResourceFilter>d__22.MoveNext() in D:\temp\Mvc-dev\src\Microsoft.AspNetCore.Mvc.Core\Internal\ControllerActionInvoker.cs:line 1105 --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Rethrow(ResourceExecutedContext context) in D:\temp\Mvc-dev\src\Microsoft.AspNetCore.Mvc.Core\Internal\ControllerActionInvoker.cs:line 1377 at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted) in D:\temp\Mvc-dev\src\Microsoft.AspNetCore.Mvc.Core\Internal\ControllerActionInvoker.cs:line 493 at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.<InvokeAsync>d__20.MoveNext() in D:\temp\Mvc-dev\src\Microsoft.AspNetCore.Mvc.Core\Internal\ControllerActionInvoker.cs:line 164 --- End of stack trace from previous location where exception was thrown --- at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) 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.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at System.Runtime.CompilerServices.TaskAwaiter.GetResult() at Microsoft.AspNetCore.Session.SessionMiddleware.<Invoke>d__9.MoveNext() in D:\temp\Session-dev\Session-dev\src\Microsoft.AspNetCore.Session\SessionMiddleware.cs:line 106 --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at Microsoft.AspNetCore.Session.SessionMiddleware.<Invoke>d__9.MoveNext() in D:\temp\Session-dev\Session-dev\src\Microsoft.AspNetCore.Session\SessionMiddleware.cs:line 123 --- End of stack trace from previous location where exception was thrown --- at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.<Invoke>d__7.MoveNext() Exception thrown: 'System.InvalidOperationException' in Microsoft.AspNetCore.Http.dll Microsoft.AspNetCore.Server.Kestrel: Error: Connection id "0HL1I8OFS17SU": An unhandled exception was thrown by the application. System.InvalidOperationException: Session has not been configured for this application or request. at Microsoft.AspNetCore.Http.DefaultHttpContext.get_Session() at Microsoft.AspNetCore.Mvc.ViewFeatures.SessionStateTempDataProvider.SaveTempData(HttpContext context, IDictionary`2 values) in D:\temp\Mvc-dev\src\Microsoft.AspNetCore.Mvc.ViewFeatures\ViewFeatures\SessionStateTempDataProvider.cs:line 57 at Microsoft.AspNetCore.Mvc.ViewFeatures.TempDataDictionary.Save() in D:\temp\Mvc-dev\src\Microsoft.AspNetCore.Mvc.ViewFeatures\ViewFeatures\TempDataDictionary.cs:line 166 at Microsoft.AspNetCore.Mvc.ViewFeatures.Internal.SaveTempDataFilter.SaveTempData(IActionResult result, ITempDataDictionaryFactory factory, HttpContext httpContext) in D:\temp\Mvc-dev\src\Microsoft.AspNetCore.Mvc.ViewFeatures\Internal\SaveTempDataFilter.cs:line 91 at Microsoft.AspNetCore.Mvc.ViewFeatures.Internal.SaveTempDataFilter.<>c.<OnResultExecuting>b__5_0(Object state) in D:\temp\Mvc-dev\src\Microsoft.AspNetCore.Mvc.ViewFeatures\Internal\SaveTempDataFilter.cs:line 57 at Microsoft.AspNetCore.Server.Kestrel.Internal.Http.Frame.<FireOnStarting>d__178.MoveNext() Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware: Error: An exception was thrown attempting to display the error page. System.ObjectDisposedException: The response has been aborted due to an unhandled application exception. ---> System.InvalidOperationException: Session has not been configured for this application or request. at Microsoft.AspNetCore.Http.DefaultHttpContext.get_Session() at Microsoft.AspNetCore.Mvc.ViewFeatures.SessionStateTempDataProvider.SaveTempData(HttpContext context, IDictionary`2 values) in D:\temp\Mvc-dev\src\Microsoft.AspNetCore.Mvc.ViewFeatures\ViewFeatures\SessionStateTempDataProvider.cs:line 57 at Microsoft.AspNetCore.Mvc.ViewFeatures.TempDataDictionary.Save() in D:\temp\Mvc-dev\src\Microsoft.AspNetCore.Mvc.ViewFeatures\ViewFeatures\TempDataDictionary.cs:line 166 at Microsoft.AspNetCore.Mvc.ViewFeatures.Internal.SaveTempDataFilter.SaveTempData(IActionResult result, ITempDataDictionaryFactory factory, HttpContext httpContext) in D:\temp\Mvc-dev\src\Microsoft.AspNetCore.Mvc.ViewFeatures\Internal\SaveTempDataFilter.cs:line 91 at Microsoft.AspNetCore.Mvc.ViewFeatures.Internal.SaveTempDataFilter.<>c.<OnResultExecuting>b__5_0(Object state) in D:\temp\Mvc-dev\src\Microsoft.AspNetCore.Mvc.ViewFeatures\Internal\SaveTempDataFilter.cs:line 57 at Microsoft.AspNetCore.Server.Kestrel.Internal.Http.Frame.<FireOnStarting>d__178.MoveNext() --- End of inner exception stack trace --- at Microsoft.AspNetCore.Server.Kestrel.Internal.Http.Frame.ThrowResponseAbortedException() at Microsoft.AspNetCore.Server.Kestrel.Internal.Http.Frame.<ProduceStartAndFireOnStartingAwaited>d__194.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at Microsoft.AspNetCore.Server.Kestrel.Internal.Http.Frame.Write(ArraySegment`1 data) at Microsoft.AspNetCore.Server.Kestrel.Internal.Http.FrameResponseStream.Write(Byte[] buffer, Int32 offset, Int32 count) at System.IO.StreamWriter.Flush(Boolean flushStream, Boolean flushEncoder) at System.IO.StreamWriter.Write(String value) at Microsoft.Extensions.RazorViews.BaseView.Write(String value) at Microsoft.AspNetCore.Diagnostics.RazorViews.ErrorPage.<ExecuteAsync>d__6.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at Microsoft.Extensions.RazorViews.BaseView.<ExecuteAsync>d__29.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.<Invoke>d__7.MoveNext() Microsoft.AspNetCore.Server.Kestrel: Error: Connection id "0HL1I8OFS17SU": An unhandled exception was thrown by the application. 

Answer 1

Finally, I realized what the problem is after gouging the source code. Asp.Net Core MVC The complex data type for TempData not currently supported. It only supports string . This is through this exception, while serializing the data, if we pass others, then string .

"Microsoft.AspNetCore.Mvc.ViewFeatures.Internal.TempDataSerializer" cannot serialize an object of type "MvcSandbox.Controllers.Alert".

I serialize my list to json and then save TempData .

Here is how I did it. I am creating an extension method to add and extract data from TempData .

 const string Alerts = "Alerts"; public static List<Alert> GetAlert(this ITempDataDictionary tempData) { CreateAlertTempData(tempData); return DeserializeAlerts(tempData[Alerts] as string); } public static void CreateAlertTempData(this ITempDataDictionary tempData) { if (!tempData.ContainsKey(Alerts)) { tempData[Alerts] = ""; } } public static void AddAlert(this ITempDataDictionary tempData, Alert alert) { if(alert == null) { throw new ArgumentNullException(nameof(alert)); } var deserializeAlertList = tempData.GetAlert(); deserializeAlertList.Add(alert); tempData[Alerts] = SerializeAlerts(deserializeAlertList); } public static string SerializeAlerts(List<Alert> tempData) { return JsonConvert.SerializeObject(tempData); } public static List<Alert> DeserializeAlerts(string tempData) { if(tempData.Length == 0) { return new List<Alert>(); } return JsonConvert.DeserializeObject<List<Alert>>(tempData); } 

Add TempData Alert

  tempData.AddAlert(new Alert(AlertClass, Message)); 

Finally, get "TempData in View" and display.

 @if (TempData.GetAlert().Count > 0) { <div class="alert-container"> @foreach (var alert in TempData.GetAlert()) { <div class="alert @alert.AlertClass alert-dismissible"> <button type="button" class="close" data-dismiss="alert" aria-hidden="true">&times;</button> @alert.Message </div> } </div> } 

Answer 2

Have you set up a session? TempData uses a session behind the scenes.

Project.json

 "Microsoft.AspNetCore.Session": "1.1.0" 

Here is the Startup.cs file. - ConfigureServices method

 public void ConfigureServices(IServiceCollection services) { services.AddSession(); services.AddMvc(); } 

And the Configure method.

 public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory) { app.UseSession(); app.UseMvc(routes => { routes.MapRoute( name: "default", template: "{controller=Home}/{action=Index}/{id?}"); }); } 

Now try with TempData, it will work.

And you can set the environment with the environment variable set ASPNETCORE_ENVIRONMENT=Development .

Answer 3

This is what I use to include Session and Temp data in Core Runtime 2.0.6.

Configure Launch Service Section

 // Add MVC service. services.AddMvc(config => { // Configure global usage of antiforgery tokens. config.Filters.Add(new AutoValidateAntiforgeryTokenAttribute()); }) .AddSessionStateTempDataProvider(); // Adds the ability to use session variables. services.AddSession(options => { options.Cookie.HttpOnly = true; });