c# – “无法转换为IComparer”

public class BoxedRegistryItemComparer : IComparer<object>
{
    public int Compare(object left,object right)
    {
        RegistryItem leftReg = (RegistryItem)left;
        RegistryItem rightReg = (RegistryItem)right;

        return string.Compare(leftReg.Name,rightReg.Name);
    }
}

我想用它来对盒装的RegistryItems的ArrayList进行排序(它确实应该是一个List< RegistryItem>,但这不受我的控制).

ArrayList regItems = new ArrayList();
// fill up the list ...
BoxedRegistryItemComparer comparer = new BoxedRegistryItemComparer();
ArrayList.sort(comparer);

但是,最后一行给出了编译器错误：“无法从BoxedRegistryItemComparer转换为System.Collections.IComparer”.如果有人能指出我的错误,我将不胜感激.