所以这里的问题是 FilesInFolder = dir.GetFiles（）。计数计数隐藏文件。即使我设置了Windows文件夹选项来显示隐藏的文件/文件夹，他们没有显示，因为他们是像相册艺术。以下行排序我的问题。

So the issue here is that FilesInFolder = dir.GetFiles().Count was counting hidden files. Even though I've set Windows folder options to show hidden files/folders, they were not shown as they were things like album art. The following line sorted my issue.

FilesInFolder = Directory.GetFiles(FullName, "*.mp3").Count

我想知道，如果有一种方法来计算多个文件类型？例如MP3和WMA？如果有人知道，我会征求意见。

I am wondering though, if there is a way to count more than one file type? I.e MP3 and WMA? If anyone happens to know, I'd apprciate a comment.