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I am new to the MVVM pattern and WCF Data Services so please bear with me.

I am trying to create a solution with a WCF DataServices project (I have followed https://msdn.microsoft.com/en-us/library/dd728275(v=vs.110).aspx for the DataService as a guide).

I then want to consume the service via a WPF application (I have followed https://msdn.microsoft.com/en-us/library/dd728278(v=vs.110).aspx as a guide which works fine but I want to start using the MVVM pattern as this application is likely to get quite large so I want to start off "doing the right thing".

My problem is when trying to move the client logic into a class to attempt to start a MVVM model I am getting a very strange error: Multiple types were found with the same name 'AdminUI.AdminServiceReference.tbl_Song, AdminUI, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null'. Type names must be unique. C:\Users\USER\Documents\Visual Studio 2013\Projects\Admin\AdminUI\UCSongs.xaml targeting the following code:

XML
<Grid.DataContext>
            <local:SongsViewModel/> <!-- Error occurs here -->
</Grid.DataContext>


I have searched and searched online and I cannot work out why I am getting this error so I am hoping someone here may be able to put me out of my misery before I resort to logic within the UI.

I am not sure if this will be a factor in any answers but I also want the client to consume the WCF service in an asynchronous way eventually.

I hope providing the following code helps:

WCF Data Service using EntityFramework (MSSQL)

C#
public class AdminWcfDataService : EntityFrameworkDataService<DBEntities>
    {
        // This method is called only once to initialize service-wide policies.
        public static void InitializeService(DataServiceConfiguration config)
        {
            config.DataServiceBehavior.MaxProtocolVersion = DataServiceProtocolVersion.V3;
            config.SetEntitySetAccessRule("*", EntitySetRights.All);
            config.SetServiceOperationAccessRule("*", ServiceOperationRights.All);
        }
    }


Client ViewModel Class

C#
public class SongsViewModel
{
    DataServiceCollection<AdminUI.AdminServiceReference.tbl_Song> _songs = new DataServiceCollection<tbl_Song>();

    public DataServiceCollection<AdminUI.AdminServiceReference.tbl_Song> Songs
    {
        get { return _songs;  }
        set { _songs = value; }
    }

    public SongsViewModel()
    {
        AdminUI.AdminServiceReference.DBEntities context = new AdminServiceReference.DBEntities(new Uri("http://localhost:59742/AdminWcfDataService.svc/"));

        var listQuery = from mylist in context.tbl_Song
                        select mylist;

        _songs = new System.Data.Services.Client.DataServiceCollection<AdminUI.AdminServiceReference.tbl_Song>(listQuery, System.Data.Services.Client.TrackingMode.AutoChangeTracking, "Songs", OnPropertyChanged, OnCollectionChanged);
    }

    private bool OnPropertyChanged(EntityChangedParams arg)
    {
        // Debug
        Console.WriteLine("Test property changed");
        return false;
    }

    private bool OnCollectionChanged(EntityCollectionChangedParams arg)
    {
        // Debug
        Console.WriteLine("Test collection changed");
        return false;
    }
}


Client UI XAML

XML
<UserControl x:Class="AdminUI.UCSongs"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             xmlns:local="clr-namespace:AdminUI"
             mc:Ignorable="d" 
             d:DesignHeight="300" d:DesignWidth="300">
    <Grid x:Name="grdMain">
        <Grid.DataContext>
            <local:SongsViewModel/> <!-- Error occurs here -->
        </Grid.DataContext>
        <ListView Name="lvMain" ItemsSource="{Binding}">
            <ListView.View>
                <GridView>
                    <GridViewColumn Header="Name" DisplayMemberBinding="{Binding SongName}"/>
                </GridView>
            </ListView.View>
        </ListView>
    </Grid>
</UserControl>


I am grateful for any answers / tips. If you require any extra information please let me know and I will try to update the question.
Posted

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