บวกเลขอย่างง่าย

1. สร้างโปรเจ็ค File --> New --> Project --> Visual Basic --> Windows Forms Application      

2. ตั้งชื่อ textbox  ที่ name ตาม Properties  ให้ตรงกัน             

Code

Public Class Form1

    Private Sub btn_sum_Click(sender As Object, e As EventArgs) Handles btn_sum.Click

        ' ปุ่มบวก

        Dim sum As Integer = Convert.ToInt32(txtbox1.Text) + Convert.ToInt32(txtbox2.Text)

        txtbox_result.Text = sum

        lable_status.Text = "การบวก"

    End Sub

    Private Sub btn_minus_Click(sender As Object, e As EventArgs) Handles btn_minus.Click

        ' ปุ่มลบ

        Dim minus As Integer = Convert.ToInt32(txtbox1.Text) - Convert.ToInt32(txtbox2.Text)

        txtbox_result.Text = minus

        lable_status.Text = "การลบ"

    End Sub

    Private Sub btn_multiply_Click(sender As Object, e As EventArgs) Handles btn_multiply.Click

       ' ปุ่มคูณ

        Dim multiply As Integer = Convert.ToInt32(txtbox1.Text) * Convert.ToInt32(txtbox2.Text)

        txtbox_result.Text = multiply

        lable_status.Text = "การคูณ"

    End Sub

    Private Sub btn_divide_Click(sender As Object, e As EventArgs) Handles btn_divide.Click

       ' ปุ่มหาร

        Dim divide As Integer = Convert.ToInt32(txtbox1.Text) / Convert.ToInt32(txtbox2.Text)

        txtbox_result.Text = divide

        lable_status.Text = "การหาร"

    End Sub

    Private Sub txtbox1_KeyPress(sender As Object, e As KeyPressEventArgs) Handles txtbox1.KeyPress

       ' ดับเบิ้ลคลิกที่ txtbox1 ของเรา แล้วเลือกอีเวนเป็น KeyPress เพิ่มโค๊ดลงไป

        Select Case Asc(e.KeyChar)

            Case 48 To 57 'ตัวเลข 0-9

            Case Keys.Back 'Backspace

            Case Else

                e.Handled = True

                msg_alert()

        End Select

    End Sub

    Private Sub txtbox2_KeyPress(sender As Object, e As KeyPressEventArgs) Handles txtbox2.KeyPress

        Select Case Asc(e.KeyChar)

            Case 48 To 57 'ตัวเลข 0-9

                'Case 42 To 47 'อักขระพิเศษ

            Case Keys.Back 'Backspace

            Case Else

                e.Handled = True

                msg_alert()

        End Select

    End Sub

    Private Sub msg_alert()

        MsgBox("สามารถใส่ได้แค่ตัวเลขเท่านั้")

    End Sub

End Class