在单元格值中绑定WPF DataGrid列标题文本

我有一个DataGrid，我希望在Cell 中的每个值中附加列标题文本

XAML源代码是

<Window x:Class="DataGrid_Index.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525"
        xmlns:cust="clr-namespace:DataGrid_Index" >
    <Grid>
        <DataGrid Name="Grid1" AutoGenerateColumns="False" ItemsSource="{Binding MobileList, UpdateSourceTrigger=PropertyChanged}" IsReadOnly="True" SelectionUnit="Cell" SelectionChanged="Grid1_SelectionChanged" >
            <DataGrid.Columns>
                <!--Column 1-->
                <DataGridTextColumn Binding="{Binding MobileName}" Header="Name" />
                <!--Column 2-->
                <DataGridTextColumn Binding="{Binding MobileOS}" Header="OS" />
            </DataGrid.Columns>
        </DataGrid>
    </Grid>
</Window>

C#视图模型是

public class MobileVM : ViewModel
{
    private ObservableCollection<Mobile> _mobileList = new ObservableCollection<Mobile>();
    public ObservableCollection<Mobile> MobileList
    {
        get { return _mobileList; }
        set { _mobileList = value; OnPropertyChanged(); }
    }
    public MobileVM()
    {
        MobileList = new ObservableCollection<Mobile>()
        {
            new Mobile() { MobileName = "iPhone 6", MobileOS = "IOS" },
            new Mobile() { MobileName = "Galaxy S6", MobileOS = "Android" },
            new Mobile() { MobileName = "Lumina", MobileOS = "Windows" }
        };
    }
}
public class Mobile
{
    public string MobileName { get; set; }
    public string MobileOS { get; set; }
}

我期待输出

        Name                  OS
_________________________________________
    Name: iPhone 6        OS: IOS
    Name: Galaxy S6       OS: Android
    Name: Lumina          OS: Windows

如何在细胞中结合Column.Header？请协助我。

<DataGridTextColumn Header="Name" x:Name="NameC">
                        <DataGridTextColumn.Binding>
                            <MultiBinding StringFormat=" {0}: {1}">
                                <Binding ElementName="NameC" Path="Header"></Binding>
                                <Binding Path="MobileName"></Binding>
                            </MultiBinding>
                        </DataGridTextColumn.Binding>
                    </DataGridTextColumn>