JIS X 0208の文字かどうかを正規表現を使わずに文字コードの範囲で判定する例。
Public Function IsJISX0208(ByVal target As String) As Boolean
Dim isOK As Boolean = True
Dim byteTarget As Byte() = System.Text.Encoding.GetEncoding(932).GetBytes(StrConv(target, VbStrConv.Wide))
For pos As Integer = 0 To byteTarget.Length - 1 Step 2
If CLng("&H" & Hex(byteTarget(pos)) & Hex(byteTarget(pos + 1))) >= &H889F AndAlso _
CLng("&H" & Hex(byteTarget(pos)) & Hex(byteTarget(pos + 1))) <= &H9872 Then
'第一水準
ElseIf CLng("&H" & Hex(byteTarget(pos)) & Hex(byteTarget(pos + 1))) >= &H989F AndAlso _
CLng("&H" & Hex(byteTarget(pos)) & Hex(byteTarget(pos + 1))) <= &HEAA4 Then
'第ニ水準
ElseIf CLng("&H" & Hex(byteTarget(pos)) & Hex(byteTarget(pos + 1))) >= &H8140 AndAlso _
CLng("&H" & Hex(byteTarget(pos)) & Hex(byteTarget(pos + 1))) <= &H849E Then
'記号数字ひらがななど
Else
'上記範囲外か
isOK = False
Exit For
End If
Next
Return isOK
End Function