Selected item not showing in a WPF combobox

Using wpf: Selected item not showing in a WPF combobox on newest questions tagged wpf – Stack Overflow

I’m creating a part of my window in code. For a combobox I do this:

ObservableCollection<ParamClassOption> options = new ObservableCollection<ParamClassOption>(
context.ParamClassOptions.Where(x => x.IDParamClass == val.CompTypeParam.IDParamClass));

ComboBox combobox = new ComboBox();
combobox.Name = "combobox" + val.CompTypeParam.ParameterName.Replace(" ", "");
combobox.ItemsSource = options;
combobox.SelectedValuePath = "IDParamClass";
combobox.DisplayMemberPath = "OptionName";
if (val.ParamClassOption != null)
{
  combobox.SelectedValue = val.ParamClassOption.IDParamClassOption;
}
layoutitem.Content = combobox;

I’m able to select an item from the list and save it to the database. The problem that I have is to show the saved value again upon retrieving the values back from the database. Any idea why it’s not showing? val.ParamClassOption.IDParamClassOption in the second to last line above has the correct value when the record is retrieved to be displayed.

source: http://stackoverflow.com/questions/11289094/selected-item-not-showing-in-a-wpf-combobox
Using wpf: using-wpf