Question

Hello guys i have dataform in silverlight 4 project item source is:

ItemsSource="{Binding Data, ElementName=domainDataSource1, Mode=TwoWay}"

and domain data source is :

<riaControls:DomainDataSource Name="domainDataSource1" QueryName="GetCarsQuery"  AutoLoad="True">
        <riaControls:DomainDataSource.DomainContext>
            <domain:DataDomainContext/>
        </riaControls:DomainDataSource.DomainContext>
    </riaControls:DomainDataSource>

My cars table have relationship with trailers table. I have combobox on my data form where i want to show all trailers marks how i can bind combobox another query?
And when user will save data how i can get trailers id with mark?

thanks

Answer 1

First let me preface this by saying ComboBoxes nested in DataForms are currently VERY buggy as of SL5. But here you go, this is using Entity Framework:

The associated class:

public class TrailerListProvider : UserControl
{
    myDomainContext _dc;
    public myDomainContext DomainContext
    {
        set
        {
            _dc = value;
            _dc.Load<trailer>(_dc.GetTrailersQuery());

        }
    }
    public TrailerListProvider()
    {
        DomainContext = new myDomainContext ();
    }
    public List<trailer> VendorList
    {
        get
        {
            return (from t in _dc.trailers
                    orderby t.trailerMark
                    select t).ToList();
        }
    }
}

In your XAML:

<Control.Resources>
    <myClasses:TrailerListProvider x:Key="trailerListProvider"></myClasses:TrailerListProvider>
</Control.Resources>

And finally in your combobox (or whatever control with ItemsSource):

ItemsSource = {Binding Path=VendorList, ElementName={StaticResource trailerListProvider}}