Fungsi IF dan CASE untuk Keputusan - Pemrograman Visual Basic .Net

Dalam membangun aplikasi sering sekali kita menjumpai dalam membuat sebuah keputusan. untuk membuat keputusan dalam bahasa pemrograman kita menggunakan dengan IF dan CASE.

If [Ekspresi Logika] Then
 [Statement 1]
Else
 [Statement 2]
End if

Select Case buatVariable
            Case "a"
            Case "b"
            Case Else
End Select

Agar lebih jelas perhatikan kode berikut

Public Class frmBarang

    Private Sub TextBox3_TextChanged(sender As Object, e As EventArgs) Handles txtHarga.TextChanged

    End Sub

    Private Sub btnBaru_Click(sender As Object, e As EventArgs) Handles btnBaru.Click
        txtKode.Focus()
        txtKode.Clear()
        txtNama.Clear()
        txtHarga.Clear()
        txtJumlah.Clear()
    End Sub
    Sub buatKolom()
        With lv.Columns
            .Add("Kode", 50, HorizontalAlignment.Center)
            .Add("Nama", 100, HorizontalAlignment.Center)
            .Add("Harga", 100, HorizontalAlignment.Center)
            .Add("Jumlah", 100, HorizontalAlignment.Center)
        End With
        lv.View = View.Details
        lv.GridLines = True
        lv.FullRowSelect = True
    End Sub

    Private Sub frmBarang_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        buatKolom()
    End Sub

    Sub isiTabel()
        Dim i As New ListViewItem
        i.Text = txtKode.Text
        i.SubItems.Add(txtNama.Text)
        i.SubItems.Add(txtHarga.Text)
        i.SubItems.Add(txtJumlah.Text)
        lv.Items.Add(i)
    End Sub

    Private Sub btnSimpan_Click(sender As Object, e As EventArgs) Handles btnSimpan.Click
        isiTabel()
    End Sub

    Private Sub btnHapus_Click(sender As Object, e As EventArgs) Handles btnHapus.Click
        If lv.Items.Count <> 0 Then
            lv.Items.Remove(lv.SelectedItems(0))
        Else
            MsgBox("Belum di pilih")
        End If
    End Sub

    Private Sub lv_Click(sender As Object, e As EventArgs) Handles lv.Click
        txtKode.Text = lv.SelectedItems(0).SubItems(0).Text
        txtNama.Text = lv.SelectedItems(0).SubItems(1).Text
        txtHarga.Text = lv.SelectedItems(0).SubItems(2).Text
        txtJumlah.Text = lv.SelectedItems(0).SubItems(3).Text
    End Sub

    Private Sub lv_SelectedIndexChanged(sender As Object, e As EventArgs) Handles lv.SelectedIndexChanged

    End Sub

    Private Sub btnEdit_Click(sender As Object, e As EventArgs) Handles btnEdit.Click
        If lv.Items.Count <> 0 Then
            With lv.SelectedItems(0)
                .SubItems(0).Text = txtKode.Text
                .SubItems(1).Text = txtNama.Text
                .SubItems(2).Text = txtHarga.Text
                .SubItems(3).Text = txtJumlah.Text
            End With
        Else
            MsgBox("Data Belum di pilih")
        End If
    End Sub

    Private Sub btnKeluar_Click(sender As Object, e As EventArgs) Handles btnKeluar.Click
        Dim x As String
        x = MsgBox("Apakah anda ingin keluar", MsgBoxStyle.OkCancel)
        If x = MsgBoxResult.Ok Then
            MsgBox("Selamat datang Jalan")
            End
        End If
    End Sub
End Class

Jika dijalankan akan menghasilkan gambar berikut:

Untuk lebih jelas perhatikan vidio berikut