如何重用usercontrol mvvm？

Question

如何重用用户控件？

我有：

<UserControl ...
         DataContext="{Binding IPAddressControlVM, Source={StaticResource Locator}}">

<Grid >
    <TextBox Text="{Binding Path=First}" />
    <TextBox Text="{Binding Path=Second}" /> 
</Grid>
</UserControl>

视图模型：

private string first;
private string second;
public string First
    {
        get
        {
            return first;
        }
        set
        {
            Set<string>(() => this.First, ref first, value);
            RaisePropertyChanged("First");
        }
    }
    public string Second
    {
        get
        {
            return second;
        }
        set
        {
            Set(() => this.Second, ref second, value);
            RaisePropertyChanged("Second");
        }
    }

免得我拥有

<Window x:Class="MainWindow"
DataContext="{Binding MainWindowVM, Source={StaticResource Locator}}" 
  ...>
<Grid>
    <local:MyUserControl/>
</Grid>

如何将uesr控件的属性绑定到MainWindow-ViewModel？

我的意思是，我需要类似的东西：

<local:MyUserControl First={Binding FirstTxt} First={Binding SecondTxt}/>