Question

Visual Basic Help:

Answer 1

Answer:

See text attachment for complete source code (for the answer) where I used comments to explain each line of the program

Explanation:

First, design the form using the following tools (and the accompanying properties) :

1 Label: Property: Text: Score

2 Buttons

Button1: Property: Name: btnAdd; Text: Add

Button2: Property: Name: btnDisplay; Text: Display

1 ListBox: Property: Visible: Hidden

1 TextBox: Property: Name: txtNum1

First, create the following function.

The function (named typecheck) validates input from the user (i.e. integer input only)

Function typecheck(ByVal input As String) As Boolean

       Try

           Convert.ToInt32(input)

           $Return\ True$

       $Catch\ ex\ As\ Exception$

           $Return\ False$

       End Try

   End Function

It returns true if the input is integer and false, if otherwise.

Next, double-click on the "Add" button and write the following lines of code:

Dim num1 As String

       num1 = txtNum1.Text

       If num1 IsNot String.Empty Then

           If typecheck(num1) Then

               $ListBox1.Items.Add(num1)$

               $txtNum1.Text = String.Empty$

           Else

               $MsgBox("Only$ $Integer$ $Inpu t")$

               $txtNum1.Text = String.Empty$

           $End\ If$

       Else

           $MsgBox("Box$ $can\ not\ be\ empty")$

           $txtNum1.Text = String.Empty$

       $End\ If$

Next, double-click on the "Display" button and write the following lines of code:

If ListBox1.Items.Count > 0 Then

           $Dim\ max1, max2\ As\ Integer$

           max1 = Convert.ToInt32(ListBox1.Items(0))

           max2 = Convert.ToInt32(ListBox1.Items(0))

           $For\ count\ = 0\ To\ ListBox1.Items.Count - 1$

               If Convert.ToInt32(ListBox1.Items($count$)) >= max1 Then

                   max1 = Convert.ToInt32(ListBox1.Items($count$))

               $End\ If$

           Next

           $For\ count\ = 0\ To\ ListBox1.Items.Count - 1$

               If Convert.ToInt32(ListBox1.Items($count$)) >= max2 And Convert.ToInt32(ListBox1.Items($count$)) < max1 Then

                   max2 = Convert.ToInt32(ListBox1.Items($count$))

               $End\ If$

           Next

           MsgBox("Highest Scores: " + max1.ToString() + " " + max2.ToString())

           MsgBox("$Total$: " + ListBox1.Items.Count.ToString())

       $End\ If$

       ListBox1.Items.Clear()