| ■No6249 (韋駄天 さん) に返信
> ただ、１＋２＋３だとか１＋３−４
> のような連続した計算の仕方がわかりません。
Public Class Form1
Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
TextBox1.Text = "1+2+3"
TextBox2.ReadOnly = True
End Sub
Sub Button1_Click(ByVal sender As Object, ByVal e As EventArgs) Handles Button1.Click
TextBox2.Text = Calc(TextBox1.Text).ToString()
End Sub
Function Calc(ByVal expression As String) As Double
Using table As New DataTable()
table.Columns.Add("ans", GetType(Double), expression)
With table.Rows.Add()
If .IsNull("ans") Then
Return Double.NaN
Else
Return DirectCast(.Item("ans"), Double)
End If
End With
End Using
End Function
End Class |