fb替换字符串中的指定子串

因为操作字符串经常会需要替换指定字串，但是fb的内置函数没有发现能实现的，所以自己写了个。

''替换字符串中的指定子串
Function StringReplace(sString As String, searchstring As String, replacestring As String) As String
    Dim As Integer p = InStr(sString, searchstring)
    Dim As String s = Mid(sString, 1, p-1) & replacestring & Mid(sString, p + Len(searchstring))
    Do While p <> 0
        p = Instr(p + 1 + Len(searchstring), s, searchstring)
        If p = 0 Then Exit Do
        s = Mid(s, 1, p-1) & replacestring & Mid(s, p + Len(searchstring))
    Loop
    Return s
End Function

''使用示例，把IP地址中的.替换成空格
?StringReplace("255.255.255.255", ".", " ")