簡易関数電卓JsCalc　Visual Basic 2010 (3)

　「Math.」を付けるのが面倒なので、付けなくてもいいように改良しました。(^_^;
　Button1_Click()をちょっと書き直して、Accept(),IsAlNum2(),SplitTok()関数を新設しました。

    Private Sub Button1_Click(
        ByVal sender As System.Object, ByVal e As System.EventArgs
    ) Handles Button1.Click

        Dim strExpr As String = Accept(TextBox1.Text)
        TextBox2.Clear()
        TextBox2.Text = JsEval(strExpr)
    End Sub

    Function Accept(ByVal expr As String) As String
        Dim result As String = Replace(expr, "Math.", "")
        Dim lst() As String = {
            "E", "LN", "LOG", "PI", "SQRT",
            "abs", "acos", "asin", "atan", "ceil", "cos", "exp", "floor", "log",
            "max", "min", "pow", "random", "round", "sin", "sqrt", "tan"
        }
        result = SplitTok(result)
        For Each target As String In lst
            result = Replace(result, vbLf + target, "Math." + target)
        Next
        result = Replace(result, vbLf, "")
        Return result
    End Function

    Function IsAlNum2(ByVal strCh As String) As Boolean
        Dim result As Boolean = False
        Dim chrCh As Char = UCase(strCh.Chars(0))

        Select Case chrCh
            Case "A" To "Z", "0" To "9", "_"
                result = True
            Case Else
                result = False
        End Select
        Return result
    End Function

    Function SplitTok(ByVal strS As String) As String
        Dim result As String = vbLf, ch As String = Strings.Left(strS, 1)
        Dim i As Integer, flag As Boolean = IsAlNum2(ch)

        result += ch
        For i = 2 To strS.Length
            ch = Mid(strS, i, 1)
            If IsAlNum2(ch) <> flag Then
                result += vbLf : flag = Not flag
            End If
            result += ch
        Next

        Return result
    End Function

　こっちの方が楽でいいかな。Button1_Click()をだけちょっと書き直して、Accept(),IsAlNum2(),SplitTok()関数は不要。(^_^;

    Private Sub Button1_Click(
        ByVal sender As System.Object, ByVal e As System.EventArgs
    ) Handles Button1.Click

        Dim sExpr As String = "with(Math){" + TextBox1.Text + "}"  '「Math.」を省略可能にするため
        TextBox2.Clear()
        TextBox2.Text = JsEval(sExpr)
    End Sub

　また、WebBrowserを使わずに、eval()関数を呼び出す方法は、こちらです。(^_^;

    Public Function jsEval(ByVal sSrc As String) As String
        Dim result As String = ""
        Dim objSC As Object = CreateObject("ScriptControl")

        objSC.language = "Jscript"
        Try
            result = objSC.CodeObject.eval(sSrc)
        Catch ex As Exception
            MsgBox(ex.Message, MsgBoxStyle.Exclamation)
            result = "Error!"
        End Try

        objSC = Nothing
        Return result
    End Function

※参考URL
●簡易関数電卓JsCalc　Visual Basic 2010
●簡易関数電卓JsCalc　Visual Basic 2010 (2)