求子串在字串中出现的次数，什么方法最快捷？

我没找到现成的函数，用正则表达式？
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dim yoursubstring as string
dim string1 as string

dim re as Regex = new Regex(yoursubstring)
dim mc as matchcollection = re.matches(string1)
msgbox mc.count

or

dim yoursubstring as string
dim string1 as string
dim string2 as string = Regex.Replace(string1,yoursubstring,"")
msgbox (string1.length - string2.length)/yoursubstring.length