RadzenDropDownDataGrid TextProperty custom value

i have a datagrid that has a dropdown datagrid that shows 4 colums when opened.
i need the TextPropery to show a string that has 4 elements that will match the datagrid it is bound to.
i think the radzen component is looking for a single value that is one column to show...

here is a part of my markup and the error i get:

 <EditTemplate Context="wexCode">
                                                    TextProperty=@(wexCode.WexReliusSourceSetting.WexReliusPlanSetting?.ReliusPlanID +" , " +wexCode.WexReliusSourceSetting.SourceID.ToString() )
                            Placeholder="Choose WexReliusSourceSetting" 
                            style="display: block; width: 100%" 

here is the runtime error:
Microsoft.AspNetCore.Components.Server.Circuits.RemoteRenderer: Warning: Unhandled exception rendering component: 'RIVERSWEXG5 , 2' is not a member of type 'Map3.Models.Mapping.WexReliusSourceSetting' (Parameter 'propertyOrFieldName')

System.ArgumentException: 'RIVERSWEXG5 , 2' is not a member of type 'Map3.Models.Mapping.WexReliusSourceSetting' (Parameter 'propertyOrFieldName')
at System.Linq.Expressions.Expression.PropertyOrField(Expression expression, String propertyOrFieldName)
at Radzen.PropertyAccess.Getter[TItem,TValue](String propertyName, Type type)
at Radzen.DropDownBase1.OnParametersSet() at Microsoft.AspNetCore.Components.ComponentBase.CallOnParametersSetAsync() at Microsoft.AspNetCore.Components.ComponentBase.RunInitAndSetParametersAsync() at Radzen.RadzenComponent.SetParametersAsync(ParameterView parameters) at Radzen.DataBoundFormComponent1.SetParametersAsync(ParameterView parameters)
at Radzen.DropDownBase`1.SetParametersAsync(ParameterView parameters)

how do i get the TextProperty to just use the data and not look for a column name ?

You should use the Template of RadzenDropDownDataGrid. TextProperty must be an existing property and nothing else.

my work around was to create a new property in my entity model with the [NotMapped] attribute
so far on display that works, still have to test it for editing and saving.....

it would be good if the property allowed an expression / razor code.