小柯茶行開張囉！

Public Class Form1
    Dim a(12) As Integer
    Dim sum(12) As Integer

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load

    End Sub

    Private Sub TextBox1_TextChanged(sender As Object, e As EventArgs) Handles TextBox1.TextChanged
        a(0) = TextBox1.Text
        sum(0) = a(0) * 25
        Label10.Text = "共" & sum(0) & "元"

    End Sub

    Private Sub TextBox2_TextChanged(sender As Object, e As EventArgs) Handles TextBox2.TextChanged
        a(1) = TextBox2.Text

        sum(1) = a(1) * 30
        Label11.Text = "共" & sum(1) & "元"

    End Sub
    Private Sub TextBox3_TextChanged(sender As Object, e As EventArgs) Handles TextBox3.TextChanged
        a(2) = TextBox3.Text
        sum(2) = a(2) * 25
        Label12.Text = "共" & sum(2) & "元"

    End Sub
    Private Sub TextBox4_TextChanged(sender As Object, e As EventArgs) Handles TextBox4.TextChanged
        a(3) = TextBox4.Text
        sum(3) = a(3) * 30
        Label13.Text = "共" & sum(3) & "元"
    End Sub
    Private Sub TextBox5_TextChanged(sender As Object, e As EventArgs) Handles TextBox5.TextChanged
        a(4) = TextBox5.Text
        sum(4) = a(4) * 35
        Label18.Text = "共" & a(4) * 35 & "元"
    End Sub
    Private Sub TextBox6_TextChanged(sender As Object, e As EventArgs) Handles TextBox6.TextChanged
        a(5) = TextBox6.Text
        sum(5) = a(5) * 40
        Label19.Text = "共" & a(5) * 40 & "元"
    End Sub
    Private Sub TextBox7_TextChanged(sender As Object, e As EventArgs) Handles TextBox7.TextChanged
        a(6) = TextBox7.Text
        sum(6) = a(6) * 45
        Label20.Text = "共" & a(6) * 45 & "元"

    End Sub
    Private Sub TextBox8_TextChanged(sender As Object, e As EventArgs) Handles TextBox8.TextChanged
        a(7) = TextBox8.Text
        sum(7) = a(7) * 50
        Label21.Text = "共" & a(7) * 50 & "元"
    End Sub
    Private Sub TextBox16_TextChanged(sender As Object, e As EventArgs) Handles TextBox16.TextChanged
        a(8) = TextBox16.Text
        sum(8) = a(8) * 50
        Label22.Text = "共" & sum(8) & "元"
    End Sub
    Private Sub TextBox15_TextChanged(sender As Object, e As EventArgs) Handles TextBox15.TextChanged
        a(9) = TextBox15.Text
        sum(9) = a(9) * 40
        Label23.Text = "共" & sum(9) & "元"
    End Sub
    Private Sub TextBox14_TextChanged(sender As Object, e As EventArgs) Handles TextBox14.TextChanged
        a(10) = TextBox14.Text
        sum(10) = a(10) * 70
        Label24.Text = "共" & sum(10) & "元"
    End Sub
    Private Sub TextBox13_TextChanged(sender As Object, e As EventArgs) Handles TextBox13.TextChanged
        a(11) = TextBox13.Text
        sum(11) = a(11) * 90
        Label25.Text = "共" & sum(11) & "元"
    End Sub

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim tol As Integer
        For i = 0 To 11
            tol += sum(i)
        Next
        Label26.Text = "本次結帳" & vbCrLf & "共" & tol & "元"
    End Sub

End Class