WPF Combobox Entity Framework Binding (MVVM) - wpf

Question

I am using the EntityFramework library in my WPF Application and I am having the following issue:
I am using the MVVM pattern (to the best of my knowledge) and I am trying to make a Combobox Lookup with EF values.
I have a Company class which contains many Offices (a class as well)
This has been modelled through the EntityFramework and all the links are correct (Office has a CompanyName which is a foreign key).
Here is the OfficeView class:
public partial class AddOffice : Window
{
private DBHelper.ResourceManagementContext context = new DBHelper.ResourceManagementContext();
public AddOffice()
{
InitializeComponent();
context.Companies.Load();
this.DataContext = context.Companies.Local;
//this.DataContext = new AddOfficeViewModel();
}
public void CloseCommandHandler(object sender, ExecutedRoutedEventArgs e)
{
this.Close();
}
}
Here is the corresponding XAML:
<Label Grid.Row="4" Grid.Column="0" Margin="10,10">Company:</Label>
<ComboBox Grid.Row="4" Grid.Column="1" Margin="10,10"
ItemsSource="{Binding}"
DisplayMemberPath="CompanyName"
SelectedValuePath="CompanyName"
SelectedValue="{Binding Path=CompanyName}"/>
I know the MVVM pattern usually passes a ViewModel to the View so how would I accomplish binding the EntityFramework Company list to the ComboBox using the OfficeViewModel?
I understand the ComboBox properties. I know the selected value would be the CompanyName from the Office object and the SeletecValuePath would be the CompanyName from the Company object.

Answer 1

In View Model:
class OfficeViewModel
{
private string _CompanyName;
public string CompanyName
{
get
{
return _CompanyName;
}
set
{
_CompanyName = value;
NotifyPropertyChanged("CompanyName");
}
}
private List<Location> _CompanyList;
public List<Location> CompanyList
{
get
{
return _CompanyList;
}
set
{
_CompanyList = value;
NotifyPropertyChanged("CompanyList");
}
}
public List<Company> GetCompanyList()
{
return (from comp in Entity.Companies select comp).ToList();
}
}
In Xaml:
Add the namespace in xaml as follows:
xmlns:ViewModels="clr-namespace:WpfMvvmApplication.ViewModels"
Add the following in window.resources:
<Window.Resources>
<ViewModels:OfficeViewModel x:Key="OfficeController"/>
</Window.Resources>
Bind the View Model to combobox:
<Label Grid.Row="4" Grid.Column="0" Margin="10,10">Company:</Label>
<ComboBox Grid.Row="4" Grid.Column="1" Margin="10,10"
ItemsSource="{Binding CompanyList, Source={StaticResource OfficeController}}"
DisplayMemberPath="CompanyName"
SelectedValuePath="CompanyName"
SelectedValue="{Binding Path=CompanyName}"/>
Hope this helps you.