C#/WPF: PropertyChanged for all Properties in ViewModel?

I've a class like this:

public class PersonViewModel : ViewModelBase //Here is the INotifyPropertyChanged Stuff
{
    public PersonViewModel(Person person)
    {
        PersonEntity = person;
    }

    public Person PersonEntity { 
        get { return PersonEntity.Name; }
        private set { PersonEntity.Name = value; RaisePropertyChanged("PersonEntity");
    }

    public string Name { 
        get { return PersonEntity.Name; }
        set { PersonEntity.Name = value; RaisePropertyChanged("Name");
    } 
    public int Age{ 
        get { return PersonEntity.Age; }
        set { PersonEntity.Age= value; RaisePropertyChanged("Age");
    } 

    public void ChangePerson(Person newPerson)
    {
        //Some Validation..
        PersonEntity = newPerson;
    }

My TextBoxes are bound to Name and Age of the ViewModel. If I change the _person object in the ViewModel, do I have to call for each Property a RaisePropertyChanged again or is there a way to do this automaticly (in my concret example I have about 15 Properties..)?

Thanks for any help.

Cheers Joseph

You can indicate all properties have changed by using null or string.Empty for the property name in PropertyChangedEventArgs. This is mentioned in the documentation for PropertyChanged.

One other solution I used to tackle the problem of: first setting the value and then calling the PropertyChangedEventArgs is by adding a Set function in my ViewModelBase which looks like this:

public class ViewModelBase : INotifyPropertyChanged
{
    protected bool Set<T>(ref T backingField, T value, [CallerMemberName] string propertyname = null)
    {
        // Check if the value and backing field are actualy different
        if (EqualityComparer<T>.Default.Equals(backingField, value))
        {
            return false;
        }

        // Setting the backing field and the RaisePropertyChanged
        backingField = value;
        RaisePropertyChanged(propertyname);
        return true;
   }
}

Instead of doing this:

public string Name { 
    get { return PersonEntity.Name; }
    set { PersonEntity.Name = value; RaisePropertyChanged("Name");
} 

You can now achieve the same by doing this:

public string Name { 
    get { return PersonEntity.Name; }
    set { Set(ref PersonEntity.Name,value);
}