如何在MVVM wpf中将多个视图模型绑定到单个xaml文件？

<Window x:Class="YourNamespace.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:YourNamespace"
        Title="MVVM Example" Height="450" Width="800">
    <Window.DataContext>
        <local:MainViewModel />
    </Window.DataContext>
    
    <Grid>
        <ContentControl Content="{Binding FirstViewModel}" />
        <ContentControl Content="{Binding SecondViewModel}" />
    </Grid>
</Window>

public class MainViewModel : INotifyPropertyChanged
{
    private FirstViewModel firstViewModel;
    public FirstViewModel FirstViewModel
    {
        get { return firstViewModel; }
        set
        {
            firstViewModel = value;
            OnPropertyChanged(nameof(FirstViewModel));
        }
    }

    private SecondViewModel secondViewModel;
    public SecondViewModel SecondViewModel
    {
        get { return secondViewModel; }
        set
        {
            secondViewModel = value;
            OnPropertyChanged(nameof(SecondViewModel));
        }
    }

    public MainViewModel()
    {
        FirstViewModel = new FirstViewModel();
        SecondViewModel = new SecondViewModel();
    }

    // 实现 INotifyPropertyChanged 接口的代码...
}