WPF Combobox Binding Entity Framework - wpf

Question

This is the class that the Entity Framework created from the Database.
namespace QuickTest
{
using System;
using System.Collections.Generic;
public partial class laender
{
public int idLaender { get; set; }
public string EU { get; set; }
public string FIBUPrefixKunde { get; set; }
public string FIBUPrefixLieferant { get; set; }
public string ISO2 { get; set; }
public string ISO3 { get; set; }
public string Land_DE { get; set; }
public string Land_EN { get; set; }
public Nullable<int> Vorwahl { get; set; }
public string KFZ { get; set; }
public string TLD { get; set; }
public Nullable<double> NeukundenLimitABC { get; set; }
}
}
And I simply want to show those values in a Datagrid (thats working)
But I want the EU property to be a combobox with just 2 simple options "Yes" and "No"
So there is no foreign Key to some other Table or something. When I am binding the SelectedItem to EU it just shows nothing and I dont know why
Here is the XAML of the DataGrid
<DataGrid x:Name="laenderDataGrid" AutoGenerateColumns="False" EnableRowVirtualization="True" ItemsSource="{Binding}" Margin="58,48,59,72" RowDetailsVisibilityMode="VisibleWhenSelected">
<DataGrid.Columns>
<DataGridTemplateColumn x:Name="eUColumn" Header="EU" Width="SizeToHeader">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<ComboBox SelectedItem="{Binding EU}">
<ComboBoxItem Content="YES"/>
<ComboBoxItem Content="NO"/>
</ComboBox>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
<DataGridTextColumn x:Name="fIBUPrefixKundeColumn" Binding="{Binding FIBUPrefixKunde}" Header="FIBUPrefix Kunde" Width="SizeToHeader"/>
<DataGridTextColumn x:Name="fIBUPrefixLieferantColumn" Binding="{Binding FIBUPrefixLieferant}" Header="FIBUPrefix Lieferant" Width="SizeToHeader"/>
<DataGridTextColumn x:Name="idLaenderColumn" Binding="{Binding idLaender}" Header="id Laender" Width="SizeToHeader"/>
<DataGridTextColumn x:Name="iSO2Column" Binding="{Binding ISO2}" Header="ISO 2" Width="SizeToHeader"/>
<DataGridTextColumn x:Name="iSO3Column" Binding="{Binding ISO3}" Header="ISO 3" Width="SizeToHeader"/>
<DataGridTextColumn x:Name="kFZColumn" Binding="{Binding KFZ}" Header="KFZ" Width="SizeToHeader"/>
<DataGridTextColumn x:Name="land_DEColumn" Binding="{Binding Land_DE}" Header="Land DE" Width="SizeToHeader"/>
<DataGridTextColumn x:Name="land_ENColumn" Binding="{Binding Land_EN}" Header="Land EN" Width="SizeToHeader"/>
<DataGridTextColumn x:Name="neukundenLimitABCColumn" Binding="{Binding NeukundenLimitABC}" Header="Neukunden Limit ABC" Width="SizeToHeader"/>
<DataGridTextColumn x:Name="tLDColumn" Binding="{Binding TLD}" Header="TLD" Width="SizeToHeader"/>
<DataGridTextColumn x:Name="vorwahlColumn" Binding="{Binding Vorwahl}" Header="Vorwahl" Width="SizeToHeader"/>
</DataGrid.Columns>
</DataGrid>
There is no binding error or any other error it's just not showing
EDIT
I got it to work I had to set the Binding to SelectedValue and SelectedValuePath to Content because I want the COntent of the Comboboxitem
SelectedValuePath="Content" SelectedValue="{Binding EU}