readonly BehaviorSubject aka BehaviorObservable

gistfile1.txt

public interface IBehaviorObservable<T> : IObservable<T>
{
    T Value { get; }
    bool TryGetValue(out T value);
}

/// <summary>
/// Exposes a BehaviorSubject's Value property while hiding the OnNext, OnError, OnComplete methods.
/// </summary>
/// <typeparam name="T">To be added.</typeparam>
public class BehaviorObservable<T> : IBehaviorObservable<T>
{
    private readonly BehaviorSubject<T> _behaviorSubject;

    public BehaviorObservable(BehaviorSubject<T> behaviorSubject)
    {
        _behaviorSubject = behaviorSubject;
    }

    public IDisposable Subscribe(IObserver<T> observer) => _behaviorSubject.Subscribe(observer);
        
    public T Value => _behaviorSubject.Value;
        
    public bool TryGetValue(out T value)
    {
        return _behaviorSubject.TryGetValue(out value);
    }
}
    
public static class BehaviorSubjectExtensions
{
    public static BehaviorObservable<T> ToBehaviorObservable<T>(this BehaviorSubject<T> bs)
    {
        var bo = new BehaviorObservable<T>(bs);
        return bo;
    }
}