WPF MVVM - 如何检测视图是否“脏”

csharp
public class ViewModel : INotifyPropertyChanged
{
    private string _name;
    private string _initialName;
    public string Name
    {
        get { return _name; }
        set
        {
            if (_name != value)
            {
                _name = value;
                RaisePropertyChanged(nameof(Name));
                IsDirty = (_name != _initialName);
            }
        }
    }
    public bool IsDirty { get; private set; }
    public ICommand SaveCommand { get; }
    public ViewModel()
    {
        _initialName = _name;
        SaveCommand = new RelayCommand(Save, () => IsDirty);
    }
    private void Save()
    {
        // Save logic here
        // ...
        _initialName = _name;
        IsDirty = false;
    }
    public event PropertyChangedEventHandler PropertyChanged;
    private void RaisePropertyChanged(string propertyName)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}

xaml
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:MyApp.ViewModels">