Dim filetxt As String = My.Computer.FileSystem.ReadAllText("f:\encryptfiles\check.en")
IO.File.WriteAllText("f:\encryptfiles\check.en", filetxt, Encoding.ASCII)
"f:\encryptfiles\check.en"是一个utf8编码的文本文档，想转换成asc2编码，用上面代码处理后中文显示的是问号，请问该怎么解决？

Dim filetxt As String = My.Computer.FileSystem.ReadAllText("f:\encryptfiles\check.en", Encoding.UTF8)