混淆隐藏方法c＃

Question

我一直在阅读Headfirst c＃，我看到一部分代码让我对隐藏方法感到有些困惑，据我所知，隐藏方法会隐藏基类中具有相同名称的方法，但为什么在这段代码中，IDE仍然从基类调用方法？谢谢你，这里是代码：

class Jewels 
{
    public string Sparkle()
    {
        return "Sparkle, sparkle!";
    }
}

class Safe
{
    private Jewels contents = new Jewels();
    private string safeCombination = "12345";
    public Jewels Open(string combination)
    {
        if (combination == safeCombination)
            return contents;
        else
            return null;
    }
    public void PickLock(Locksmith lockpicker)
    {
        lockpicker.WriteDownCombination(safeCombination);
    }
}

class Owner
{
    private Jewels returnedContents;
    public void ReceiveContents(Jewels safeContents)
    {
        returnedContents = safeContents;
        Console.WriteLine("Thank you for returning my jewels! " + safeContents.Sparkle());
    }
}

class Locksmith
{
    public void OpenSafe(Safe safe, Owner owner)
    {
        safe.PickLock(this);      
        Jewels safeContents = safe.Open(writtenDownCombination);
        ReturnContents(safeContents, owner);
    }

    private string writtenDownCombination = null;
    public void WriteDownCombination(string combination)
    {
        writtenDownCombination = combination;
    }
    public  void ReturnContents(Jewels safeContents, Owner owner)
    {
        owner.ReceiveContents(safeContents);
    }
}

class Jewelthief:Locksmith
{
    private Jewels stolenJewels = null;
     public new void ReturnContents(Jewels safeContents, Owner owner)
    {//this is the place that hiding the method ReturnContents from Locksmith
        stolenJewels = safeContents;
        Console.WriteLine("I'm stealing the contents! " + stolenJewels.Sparkle());

    }
}

输出：

  

感谢您归还我的珠宝！闪闪发光，闪闪发光！