CODEWITHSUNDEEP
asp.netasp.net-mvcentity-framework
John John
John John

Reputation: 1

What is causing the "Unable to cast object of type 'System.Data.Entity.DynamicProxies" error

I have the following POST edit action method:-

[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Edit(RackJoin rj,FormCollection formValues)
{
    try
    {
        if (ModelState.IsValid)
        {
            repository.InsertOrUpdateRack(rj.Rack, User.Identity.Name, rj.Resource.RESOURCEID);
            repository.Save();
            return RedirectToAction("Index");
        }

    }
    catch (DbUpdateConcurrencyException ex)
    {
        var entry = ex.Entries.Single();
        var databaseValues = (Rack)entry.GetDatabaseValues().ToObject();
        var clientValues = (Rack)entry.Entity;
        var entry2 = ex.Entries.Single();
        var databaseValues2 = (Resource)entry2.GetDatabaseValues().ToObject();
        var clientValues2 = (Resource)entry2.Entity;

        if (databaseValues.RU != clientValues.RU)
            ModelState.AddModelError("Rack.RU", "Current value: "
                + databaseValues.RU);

but when the DbUpdateConcurrencyException exception is raised i am getting the following exception on the following line of code var databaseValues2 = (Resource)entry2.GetDatabaseValues().ToObject();:-

Unable to cast object of type 'System.Data.Entity.DynamicProxies.Rack_81556130B3DB7E3D4F63B9FF3F15832A81A86055EED840211E95A71E1342027D' to type 'TMS.Models.Resource'. 
  Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 

 Exception Details: System.InvalidCastException: Unable to cast object of type 'System.Data.Entity.DynamicProxies.Rack_81556130B3DB7E3D4F63B9FF3F15832A81A86055EED840211E95A71E1342027D' to type 'TMS.Models.Resource'.

Source Error: 



Line 175:                var clientValues = (Rack)entry.Entity;
Line 176:                var entry2 = ex.Entries.Single();
Line 177:                var databaseValues2 = (Resource)entry2.GetDatabaseValues().ToObject();
Line 178:                var clientValues2 = (Resource)entry2.Entity;
Line 179:


 Source File:  c:\Users\Administrator\Documents\Visual Studio 2012\Projects\TMS\TMS\Controllers\RackController.cs    Line:  177 

Stack Trace: 



[InvalidCastException: Unable to cast object of type 'System.Data.Entity.DynamicProxies.Rack_81556130B3DB7E3D4F63B9FF3F15832A81A86055EED840211E95A71E1342027D' to type 'TMS.Models.Resource'.]
   TMS.Controllers.RackController.Edit(RackJoin rj, FormCollection formValues) in c:\Users\Administrator\Documents\Visual Studio 2012\Projects\TMS\TMS\Controllers\RackController.cs:177
   lambda_method(Closure , ControllerBase , Object[] ) +245
   System.Web.Mvc.ActionMethodDispatcher.Execute(ControllerBase controller, Object[] parameters) +59
   System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters) +435
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +60
   System.Web.Mvc.Async.AsyncControllerActionInvoker.InvokeSynchronousActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +50
   System.Web.Mvc.Async.<>c__DisplayClass42.<BeginInvokeSynchronousActionMethod>b__41() +75
   System.Web.Mvc.Async.<>c__DisplayClass8`1.<BeginSynchronous>b__7(IAsyncResult _) +44
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +139

Upvotes: 0

Views: 3547

Answers (1)

Chris
Chris

Reputation: 8656

I'm not entirely clear what's going on in this section of code, are you meant to be retrieving the Resource from the second context you mentioned in your comment?

 var entry = ex.Entries.Single();
 var databaseValues = (Rack)entry.GetDatabaseValues().ToObject();
 var clientValues = (Rack)entry.Entity;

 var entry2 = ex.Entries.Single();
 var databaseValues2 = (Resource)entry2.GetDatabaseValues().ToObject();
 var clientValues2 = (Resource)entry2.Entity;

If you called Single() on a sequence that contained more than one element, you would generate an exception; since Single isn't generating an exception, you only have one entry present which you're using in both cases.

In the first you want to treat it as a Rack, which doesn't seem to generate a complaint. In the second, you're treating it as a Resource, which seems to be incompatible with Rack, the cause of your complaint.

InvalidCastException: Unable to cast object of type 'System.Data.Entity.DynamicProxies.Rack_81...' to type 'TMS.Models.Resource'.]

The reason your exception only contains that particular entity may well be found in your InsertOrUpdateRack method.

Upvotes: 2

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