在ReactiveUI中提升property的正确方法

Question

有时我需要为相关属性提高propertychanged,如下所示:

public bool IsValid
    {
        get { return _isValid; }
        set
        {
            if (value.Equals(_isValid)) return;
            _isValid = value;
            OnPropertyChanged("IsValid");
            OnPropertyChanged("IsSavable");
        }
    }

我可以像这样写:

public bool IsValid
    {
        get { return _isValid; }
        set
        {
            if (value.Equals(_isValid)) return;
            _isValid = value;
            this.RaisePropertyChanged("IsValid");
            this.RaisePropertyChanged("IsSavable");
        }
    }

代码基于保罗的回答:

    public ViewModelBase()
    {
        Validator = new AlwaysTrueValidValidator<ViewModelBase>();
        // logic for IsSavable
        this.WhenAny(x => x.IsValid, x => x.IsDirty, x => x.IsBusy, (valid, dirty, busy) => valid.Value && dirty.Value && busy.Value == false)
            .ToProperty(this, x => x.IsSavable, out _isSavable);
    }

    readonly ObservableAsPropertyHelper<bool> _isSavable;
    public bool IsSavable
    {
        get { return _isSavable.Value; }
    }

    [UsedImplicitly]
    public bool IsValid
    {
        get { return _isValid; }
        set { this.RaiseAndSetIfChanged(ref _isValid, value); }
    }

    public void OnPropertyChanged(string property)
    {
        // ReSharper disable once ExplicitCallerInfoArgument
        this.RaisePropertyChanged(property);
    }

正如您所看到的那样,代码更清晰,所有内容都得到/设置,逻辑就在一个地方.

有更聪明的方法吗？是

Answer 1

在ReactiveUI中,执行此操作的愿望意味着您正在做错(或者至少不是RxUI方式).IsSaveable与IsValid有关,您应该使用WhenAny和描述ToProperty.也许你可以这样写:

this.WhenAny(x => x.IsValid, x => x.IsChanged, (valid, changed) => valid.Value && changed.Value)
    .ToProperty(this, x => x.IsSavable, out isSavable);