我目前正在尝试将字符串转换为double，然后查看是否引发异常。但这似乎正在放缓我的申请。

Try
    ' if number then format it.
    current = CDbl(x)
    current = Math.Round(current,d)
    Return current
Catch ex As System.InvalidCastException
    ' item is not a number,do not format... leave as a string
    Return x
End Try