Csharp 如何在C#中实现非抛出`MinBy`

我正在try 实现一个函数，它过滤掉一些条目，并取由具体函数映射的最小值，然后要么返回由它判断的最小值，要么在过滤掉所有元素后得到null:

public readonly record struct PdfVerticalPos(float Raw_LessIsBelow)
{
}

public readonly record struct AxisAlignedRenderingBox
{
    public AxisAlignedRenderingBox(PdfVerticalPos upMost, PdfVerticalPos downMost, float leftMostRaw, float rightMostRaw)
    {
        this.UpMost = upMost;
        this.DownMost = downMost;
        this.LeftMost = leftMostRaw;
        this.RightMost = rightMostRaw;
    }
}

private static string? findTheBottomByCondition(IEnumerable<(AxisAlignedRenderingBox, string)> detectedStrings,
    float leftMostMin, float leftMostMax, Func<(AxisAlignedRenderingBox, string), bool> selectingPredicate)
{
    return detectedStrings
        .Where(selectingPredicate)
        .Where(tuple => leftMostMin <= tuple.Item1.LeftMost && tuple.Item1.LeftMost <= leftMostMax)
        .MinBy(tuple => tuple.Item1.UpMost.Raw_LessIsBelow).Item2;
}

internal void someCallSite() {
    var detectedStrings = whatever();
    var found = findTheBottomByCondition(detectedStrings, 60, 65,
                    tuple => tuple.Item1.UpMost.Raw_LessIsBelow >= baseY);
    // do whatever
}

然而，当呼叫MinBy时，它会抛出InvalidOperationException.当我判断原因时，我发现文档上写着"如果TSource是一个原始类型并且源序列为空，则抛出InvalidOperationException".不确定"基本类型"是什么意思，因为元组显然不是opposed to integers的基本类型.

因此，我重写了findTheBottomByCondition条，如下所示:

private static string? findTheBottomByCondition(IEnumerable<(AxisAlignedRenderingBox, string)> detectedStrings,
    float leftMostMin, float leftMostMax, Func<(AxisAlignedRenderingBox, string), bool> selectingPredicate) {
    
    var valueTuples = detectedStrings.ToList();
    var a = valueTuples
            .Where(selectingPredicate)
            .Count(tuple => leftMostMin <= tuple.Item1.LeftMost && tuple.Item1.LeftMost <= leftMostMax);
    if (a > 0)
    {
        return valueTuples
            .Where(selectingPredicate)
            .Where(tuple => leftMostMin <= tuple.Item1.LeftMost && tuple.Item1.LeftMost <= leftMostMax)
            .MinBy(tuple => tuple.Item1.UpMost.Raw_LessIsBelow).Item2;
    }
    else
    {
        return null;
    }
}

虽然它工作正常，但不是很优雅，只是避免了异常.我希望它返回null，如果没有找到它，不管它是不是"原始类型"，你有什么 idea 吗？我想我可以通过catch-ING InvalidOperationException来实现它，但我不喜欢这种方式，也不喜欢目前大多数复制粘贴和糟糕的实现.