Membuat Aplikasi “Simple Calculator” dengan Visual Basic.NET 2010

Seperti janji saya sebelumnya kali ini saya terapkan pembuatan aplikasi ini dengan Visual Basic.NET dan jika teman-teman bandingkan dari kedua gambarnya aplikasi ini saya buat semirip mungkin tampilannya dalam pembuatan aplikasi serupa dengan menggunakan Visual Basic 6. Sehingga kita dapat membandingkannya secara langsung perbedaan perintah dari kedua bahasa pemrograman ini. Untuk selanjutnya saya masih akan terus mengembangkan pembuatan aplikasi dengan prosedur aritmatika tetapi mungkin sama halnya dengan aplikasi ini bersifat sederhana.

1. Jalankan terlebih dahulu aplikasi Visual Basic 2010

2. Pada tabulasi “Start Page” pilih “New Project” atau bisa juga dengan menekan tombol “Ctrl + N” pada keyboard

3. Pada jendela “New Project” pilih “Windows Forms Application” kemudian tekan tombol “OK”

4. Berikut setingan kontrol properti yang terdapat pada aplikasi ini

Object	Name	Properties	Setting
Form	Form1	Form Border Style	Fixed Single
		Maximize Box	False
		Minimize Box	False
		Start Position	Center Screen
		Text	Simple Calculator
Label	lblFirst	Font	Tahoma; 10pt
		Text	First Number :
Text Box	txtFirst	Font	Tahoma; 12pt
		Text Align	Right
Label	lblSecond	Font	Tahoma; 10pt
		Text	Second Number :
Text Box	txtSecond	Font	Tahoma; 12pt
		Text Align	Right
Button	cmdAdd	Font	Tahoma; 10pt
		Text	Add
Button	cmdSubtract	Font	Tahoma; 10pt
		Text	Subtract
Button	cmdMultiple	Font	Tahoma; 10pt
		Text	Multiple
Button	cmdDevide	Font	Tahoma; 10pt
		Text	Divide
Label	lblResult	Font	Tahoma; 10pt
		Text	Result :
Text Box	txtResult	Font	Tahoma; 12pt
		Text Align	Right
Button	cmdClear	Font	Tahoma; 10pt
		Text	Clear
Button	cmdExit	Font	Tahoma; 10pt
		Text	Exit

5. Berikut event code program

Public Class Form1

    Private Sub txtFirst_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles txtFirst.KeyPress
        If e.KeyChar = ChrW(Keys.Enter) Then SendKeys.Send("{tab}")

        If Not (e.KeyChar >= ChrW(Keys.D0) And e.KeyChar <= ChrW(Keys.D9) Or e.KeyChar = ChrW(Keys.Back)) Then
            e.KeyChar = ChrW(0)
        End If
    End Sub

    Private Sub txtSecond_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles txtSecond.KeyPress
        If e.KeyChar = ChrW(Keys.Enter) Then SendKeys.Send("{tab}")

        If Not (e.KeyChar >= ChrW(Keys.D0) And e.KeyChar <= ChrW(Keys.D9) Or e.KeyChar = ChrW(Keys.Back)) Then
            e.KeyChar = ChrW(0)
        End If
    End Sub

    Private Sub txtResult_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtResult.TextChanged
        cmdClear.Enabled = True
    End Sub

    Private Sub txtSecond_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtSecond.TextChanged
        cmdAdd.Enabled = True
        cmdSubtract.Enabled = True
        cmdMultiple.Enabled = True
        cmdDevide.Enabled = True

        If txtSecond.Text = "" Then
            cmdAdd.Enabled = False
            cmdSubtract.Enabled = False
            cmdMultiple.Enabled = False
            cmdDevide.Enabled = False
        End If
    End Sub

    Private Sub cmdExit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdExit.Click
        End
    End Sub

    Private Sub cmdAdd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdAdd.Click
        txtResult.Text = Val(txtFirst.Text) + Val(txtSecond.Text)
    End Sub

    Private Sub cmdSubtract_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdSubtract.Click
        txtResult.Text = Val(txtFirst.Text) - Val(txtSecond.Text)
    End Sub

    Private Sub cmdMultiple_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdMultiple.Click
        txtResult.Text = Val(txtFirst.Text) * Val(txtSecond.Text)
    End Sub

    Private Sub cmdDevide_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdDevide.Click
        txtResult.Text = Val(txtFirst.Text) / Val(txtSecond.Text)
    End Sub

    Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        txtResult.BackColor = Color.FromKnownColor(KnownColor.Window)
    End Sub

    Private Sub cmdClear_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdClear.Click
        txtFirst.Text = ""
        txtSecond.Text = ""
        txtResult.Text = ""
        cmdClear.Enabled = False
        txtFirst.Focus()
    End Sub

End Class