I’m currently still investigating this issue and need more time to provide you with solution, suggestion, or sample.

I’ll get back to you as soon as possible.

Edited: adding reply information

It is suggested to create the new command in the view model class rather than create it in the ViewModelBase, in this case is in the EditableGridViewModelBase.

The snippet code below shows how add the new command in ProductsViewModel class.

internal override void ExecuteUpdateRow(object parameter)
{   
    Product oldValue = parameter as Product;
    Product prod = new Product();
    prod.ProductID = 0;
    prod.ProductName = oldValue.ProductName;
    prod.Category = oldValue.Category;
    prod.UnitPrice = oldValue.UnitPrice;
    prod.UnitsInStock = oldValue.UnitsInStock;
    prod.UnitsOnOrder = oldValue.UnitsOnOrder;
    prod.QuantityPerUnit = oldValue.QuantityPerUnit;
    prod.Discontinued = oldValue.Discontinued;
    ExecuteInsertRow(prod);
    base.ExecuteUpdateRow(parameter);
}

In order to set/change the primary key, you can try to set it to 0 value (using technique that mimic when user add new row)

internal override void ExecuteUpdateRow(object parameter)
{   
    Product oldValue = parameter as Product;
    Product prod = new Product();
    prod.ProductID = 0;
    ...
}

The same approach also shows how to get the “Product” object.

Hope this helps.

Hi Yudi

Thanks for very helpful sample! For all with the same problem. I've implemented it like this:

Changes in EditableGridViewModelGenericBase.cs

public EditableGridViewModelBase()
    : base()
{
    // Batch update is not supported in WCF RIA Services.
    this.IsBatchUpdate = false;
    this.AutoEditOperation = false;

    this.DeleteRowCommand = new DelegateCommand(ExecuteDeleteRow);
    ...
    this.DuplicateRowCommand = new DelegateCommand(ExecuteDuplicateRow);
}


public DelegateCommand DuplicateRowCommand { get; set; }


protected virtual void ExecuteDuplicateRow(object parameter)
{
    this.EditableProductsSource.Insert(parameter as T);

    if (!this.IsBatchUpdate)
        this.SaveChanges();
    else
        this.HasChanges = true;
}

Changes in *ViewModel.cs

protected override void ExecuteDuplicateRow(object parameter)
{
    Person currentPerson = parameter as Person;
    Person duplicatePerson = new Person();
    duplicatePerson.ID = System.Guid.Empty; //.NewGuid();
    duplicatePerson.Name = currentPerson.Name + " - Copy";
    duplicatePerson.Vorname = currentPerson.Vorname;
    base.ExecuteDuplicateRow(duplicatePerson);
}

Regards

Michael