c# - 尽管集合中的所有值均为 false，Linq Any 仍返回 true

Question

我在属性值计算中看到非常奇怪的行为。我有一个属性 HasChanged，如果它的任何依赖属性为 true，则该属性为 true。但我得到了一个结果——所有的论点都是假的，结果是真的。我使用的是MVVM Light框架，每个属性都是INotifyPropertyChanged

这是辅助函数

    private static bool PropertyWrapper(bool value, [CallerMemberName] string callerName = "")
    {
        Logger.Debug($"[{callerName}: {value}]");
        return value;
    }

    private static T PropertyWrapper<T>(Expression<Func<T>> property)
    {
        var compiled = property.Compile();
        var result = (T)compiled.DynamicInvoke();
        Logger.Debug($"[{GetName(property)}: {result}]");
        return result;
    }

    private static string GetName<T>(Expression<Func<T>> expr)
    {
        var mexpr = expr.Body as MemberExpression;
        if (mexpr == null) return "(null)";
        if (mexpr.Member == null) return "((null))";
        return mexpr.Member.Name;
    }

这是代码

    public virtual bool HasChanged => PropertyWrapper(new[] {
        PropertyWrapper(() => TitleChanged),
        PropertyWrapper(() => EnglishTitleChanged),
        PropertyWrapper(() => OriginalTitleChanged),
        PropertyWrapper(() => PlotChanged),
        PropertyWrapper(() => OutlineChanged),
        PropertyWrapper(() => DirectorChanged),
        PropertyWrapper(() => YearChanged),
        PropertyWrapper(() => MovieRolesChanged),
        PropertyWrapper(() => GenresChanged),
        PropertyWrapper(() => CountriesChanged)
    }.Any(), "HasChanged");

    public bool YearChanged => this.state == State.Edit && this.source.MovieDescription.Year != this.clone.MovieDescription.Year;
    public bool TitleChanged => HasTitleChanges();
    public bool EnglishTitleChanged => HasEnglishTitleChanges();
    public bool OriginalTitleChanged => HasOriginalTitleChanges();
    public bool PlotChanged => HasDescriptionChanges();
    public bool DirectorChanged => HasDirectorChanges();
    public bool OutlineChanged => HasOutlineChanges();
    public bool MovieRolesChanged => HasMovieRolesChanges();
    public bool CountriesChanged => HasCountriesChanges();
    public bool GenresChanged => HasGenresChanges();

以及写入日志的内容

[TitleChanged: False]

[EnglishTitleChanged: False]

[OriginalTitleChanged: False]

[PlotChanged: False]

[OutlineChanged: False]

[DirectorChanged: False]

[YearChanged: False]

[MovieRolesChanged: False]

[GenresChanged: False]

[CountriesChanged: False]

[HasChanged: True]

看起来不可能很无聊，但我无法想象怎么会这样。请解释一下这种行为的原因。

Answer 1

Any如果集合中有任何元素，则不带参数返回。要获得您想要的内容，您必须检查元素的值，如 Any谓词:

public virtual bool HasChanged => PropertyWrapper(new[] {
       //...
       }.Any(q => q), "HasChanged");