In this very simple example:
available at:
https://drive.google.com/file/d/1VnKh-wP8GJZsrdIfClCjzo6Ym6SubS9a/view?usp=sharing
you can see how when you select an item in the DropDownDataGrid, it fails with the following error:
blazor.server.js:19 [2021-10-05T09:22:39.452Z] Error: System.NotSupportedException: Unable to cast the type 'BlazorRadzenTests.Country' to type 'System.Object'. LINQ to Entities only supports casting EDM primitive or enumeration types.
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.ValidateAndAdjustCastTypes(TypeUsage toType, TypeUsage fromType, Type toClrType, Type fromClrType)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.GetCastTargetType(TypeUsage fromType, Type toClrType, Type fromClrType, Boolean preserveCastForDateTime)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.CreateCastExpression(DbExpression source, Type toClrType, Type fromClrType)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.CastMethodTranslator.Translate(ExpressionConverter parent, MethodCallExpression call)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.SequenceMethodTranslator.Translate(ExpressionConverter parent, MethodCallExpression call, SequenceMethod sequenceMethod)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.TypedTranslate(ExpressionConverter parent, MethodCallExpression linq)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.TypedTranslator`1.Translate(ExpressionConverter parent, Expression linq)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.TranslateExpression(Expression linq)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.Convert()
at System.Data.Entity.Core.Objects.ELinq.ELinqQueryState.GetExecutionPlan(Nullable`1 forMergeOption)
at System.Data.Entity.Core.Objects.ObjectQuery`1.<>c__DisplayClass41_0.<GetResults>b__1()
at System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransaction[T](Func`1 func, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction, Boolean releaseConnectionOnSuccess)
at System.Data.Entity.Core.Objects.ObjectQuery`1.<>c__DisplayClass41_0.<GetResults>b__0()
at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute[TResult](Func`1 operation)
at System.Data.Entity.Core.Objects.ObjectQuery`1.GetResults(Nullable`1 forMergeOption)
at System.Data.Entity.Core.Objects.ObjectQuery`1.<System.Collections.Generic.IEnumerable<T>.GetEnumerator>b__31_0()
at System.Data.Entity.Internal.LazyEnumerator`1.MoveNext()
at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
at Radzen.DropDownBase`1.get_View()
at Radzen.DropDownBase`1.SetSelectedIndexFromSelectedItem()
at Radzen.DropDownBase`1.SelectItem(Object item, Boolean raiseChange)
at Radzen.Blazor.RadzenDropDownDataGrid`1.OnRowSelect(Object item)
at Microsoft.AspNetCore.Components.ComponentBase.CallStateHasChangedOnAsyncCompletion(Task task)
at Radzen.Blazor.RadzenDataGrid`1.OnRowSelect(Object item, Boolean raiseChange)
at Radzen.Blazor.RadzenDataGrid`1.OnRowClick(DataGridRowMouseEventArgs`1 args)
at Radzen.Blazor.RadzenDataGridCell`1.OnClick(MouseEventArgs args)
at Microsoft.AspNetCore.Components.ComponentBase.CallStateHasChangedOnAsyncCompletion(Task task)
at Microsoft.AspNetCore.Components.RenderTree.Renderer.GetErrorHandledTask(Task taskToHandle)
This also happened after v2.15.13 but was fixed after I reported it.
Now, I have been checking old versions and the last version that had this working properly was 3.4.0. It is broken since 3.4.1