按钮已经移动，点击却留在原地：UI 布局与命中区域必须同修订提交

readonly record struct Rect(double X, double Y, double Width, double Height)
{
    public double Right => X + Width;
    public double Bottom => Y + Height;

    public bool IsValid =>
        double.IsFinite(X) && double.IsFinite(Y) &&
        double.IsFinite(Width) && double.IsFinite(Height) &&
        Width > 0 && Height > 0;

    public bool Contains(Rect other) =>
        X <= other.X && Y <= other.Y &&
        Right >= other.Right && Bottom >= other.Bottom;

    public bool Contains(double x, double y) =>
        x >= X && x <= Right && y >= Y && y <= Bottom;
}

sealed record LayoutSnapshot(long Revision, Rect VisualRect, Rect HitRect);
sealed record LayoutCandidate(long Revision, Rect? VisualRect, Rect? HitRect);

enum CommitResult
{
    Committed,
    MissingVisualRect,
    MissingHitRect,
    InvalidRect,
    HitRectDoesNotContainVisual,
    StaleRevision
}

sealed class LayoutOwner
{
    public LayoutSnapshot Current { get; private set; }

    public LayoutOwner(LayoutSnapshot initial) => Current = initial;

    public CommitResult TryCommit(LayoutCandidate candidate)
    {
        if (candidate.Revision <= Current.Revision)
            return CommitResult.StaleRevision;
        if (candidate.VisualRect is not { } visual)
            return CommitResult.MissingVisualRect;
        if (candidate.HitRect is not { } hit)
            return CommitResult.MissingHitRect;
        if (!visual.IsValid || !hit.IsValid)
            return CommitResult.InvalidRect;
        if (!hit.Contains(visual))
            return CommitResult.HitRectDoesNotContainVisual;

        Current = new LayoutSnapshot(candidate.Revision, visual, hit);
        return CommitResult.Committed;
    }

    public bool HitTest(double x, double y) => Current.HitRect.Contains(x, y);
}

$ dotnet build ./UiLayoutSnapshotLab.csproj -c Release
Build succeeded.
    0 Warning(s)
    0 Error(s)
exit=0 wall=8.55s

$ dotnet run --project ./UiLayoutSnapshotLab.csproj -c Release --no-build
tests pass=8 fail=0 skip=0 duration_ms=34.841
missing_hit=MissingHitRect revision_after_failure=1 point_305_60_before=False
complete=Committed revision_after_success=2 point_305_60_after=True
exit=0 wall=1.95s