Simple Fixed Array: Part 3

Simple Fixed Array Part 3 (The Final)

Here is the last in this series of ‘Simple Fixed Arrays’. This time, we will replace elements in the array and update all the RadioButtons, TextBox, ComboBox, and Label to reflect the changes we make. Let’s start as always with the Dim statements.

Dim arrAnimal(5) As String
Dim AnimalIndex As Integer
Dim i As Integer

Notice that this time the number inside the parenthesis is 5, the reason for this is that VB numbers the elements 0 to 5, so because we have 6 elements, the array number = 5, strange but true. I know that we got away with it last time when we placed 6 inside the parenthesis but this time, if we try to use 6, we will get errors; try it and see what happens.

Let's move on to the loading of the form. This time, we fill the array with the text of the six RadioButtons, as follows:

Private Sub AnimalArray_Load(ByVal sender As System.Object, _
            ByVal e As System.EventArgs) Handles MyBase.Load
    arrAnimal(0) = RadioButton1.Text
    arrAnimal(1) = RadioButton2.Text
    arrAnimal(2) = RadioButton3.Text
    arrAnimal(3) = RadioButton4.Text
    arrAnimal(4) = RadioButton5.Text
    arrAnimal(5) = RadioButton6.Text
    RadioButton1.Checked = True
End Sub

Next we need the RadioButton events to update LblDisplay and change the ComboBox text, this is done for all six RadioButtons.

Private Sub RadioButton1_CheckedChanged(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles RadioButton1.CheckedChanged

    LblDisplay.Text = "The " & RadioButton1.Text & Chr(13) & "is Element [" & _
      (Array.IndexOf(arrAnimal, RadioButton1.Text)) & "]" & Chr(13) & "in the Array"
    cmbArrNum.Text = "0"
End Sub

Now let’s add some code so that when we click the Load button, the elements of the array will be show in a TextBox.

Private Sub btnShowAll_Click(ByVal sender As System.Object, _
            ByVal e As System.EventArgs) Handles btnShowAll.Click
    ListBox1.Items.Clear()
    For i = 0 To 5
        ListBox1.Items.Add(arrAnimal(i) & " is element [" & i & "] in the array")
    Next
End Sub

The next button to sort out is the Sort button; this will place all the elements of the array in alphabetical order; it also updates the text for the six RadioButtons and the Label text.

Private Sub btnSort_Click(ByVal sender As System.Object, _
            ByVal e As System.EventArgs) Handles btnSort.Click
    ListBox1.Items.Clear()
    Array.Sort(arrAnimal)
    For i = 0 To 5
        ListBox1.Items.Add(arrAnimal(i) & " is element [" & i & "] in the array")
    Next
    RadioButton1.Text = arrAnimal(0)
    RadioButton2.Text = arrAnimal(1)
    RadioButton3.Text = arrAnimal(2)
    RadioButton4.Text = arrAnimal(3)
    RadioButton5.Text = arrAnimal(4)
    RadioButton6.Text = arrAnimal(5)
    Select Case cmbArrNum.SelectedIndex
        Case 0
            RadioButton1.Checked = True
            lblDisplay.Text = "The " & RadioButton1.Text & _
              Chr(13) & " is Element [" & _
              (Array.IndexOf(arrAnimal, RadioButton1.Text)) & "]" & _
              Chr(13) & "in the Array"
        Case 1
            RadioButton2.Checked = True
            lblDisplay.Text = "The " & RadioButton2.Text & _
              Chr(13) & " is Element [" & _
              (Array.IndexOf(arrAnimal, RadioButton2.Text)) & "]" & _
              Chr(13) & "in the Array"
        Case 2
            RadioButton3.Checked = True
            lblDisplay.Text = "The " & RadioButton3.Text & _
              Chr(13) & " is Element [" & _
              (Array.IndexOf(arrAnimal, RadioButton3.Text)) & "]" & _
              Chr(13) & "in the Array"
        Case 3
            RadioButton4.Checked = True
            lblDisplay.Text = "The " & RadioButton4.Text & Chr(13) & _
              " is Element [" & (Array.IndexOf(arrAnimal, RadioButton4.Text)) & _
              "]" & Chr(13) & "in the Array"
        Case 4
            RadioButton5.Checked = True
            lblDisplay.Text = "The " & RadioButton5.Text & Chr(13) & _
              " is Element [" & (Array.IndexOf(arrAnimal, RadioButton5.Text)) & _
              "]" & Chr(13) & "in the Array"
        Case 5
            RadioButton6.Checked = True
            lblDisplay.Text = "The " & RadioButton6.Text & Chr(13) & _
              " is Element [" & (Array.IndexOf(arrAnimal, RadioButton6.Text)) & _
              "]" & Chr(13) & "in the Array"
    End Select
    txtReplace.Text = ""
End Sub

That was a lot of code! Still it is Part 3 the final. Let’s move on and write some code to replace the elements in the array. Once again, because we changed the array, we need to update all the controls on the Form to keep everything updated.

Private Sub btnReplace_Click(ByVal sender As System.Object, _
            ByVal e As System.EventArgs) Handles btnReplace.Click
    If txtReplace.Text = "" Then
        MessageBox.Show("No text has been entered")
        Exit Sub
    End If
    arrAnimal.SetValue(txtReplace.Text, cmbArrNum.SelectedIndex)
    Select Case cmbArrNum.SelectedIndex
        Case 0
            RadioButton1.Text = txtReplace.Text
            RadioButton1.ForeColor = Color.Blue
        Case 1
            RadioButton2.Text = txtReplace.Text
            RadioButton2.ForeColor = Color.Blue
        Case 2
            RadioButton3.Text = txtReplace.Text
            RadioButton3.ForeColor = Color.Blue
        Case 3
            RadioButton4.Text = txtReplace.Text
            RadioButton4.ForeColor = Color.Blue
        Case 4
            RadioButton5.Text = txtReplace.Text
            RadioButton5.ForeColor = Color.Blue
        Case 5
            RadioButton6.Text = txtReplace.Text
            RadioButton6.ForeColor = Color.Blue
    End Select
    ListBox1.Items.Clear()
    For i = 0 To 5
        ListBox1.Items.Add(arrAnimal(i) & " is element [" & i & "] in the array")
    Next
    arrAnimal(0) = RadioButton1.Text
    arrAnimal(1) = RadioButton2.Text
    arrAnimal(2) = RadioButton3.Text
    arrAnimal(3) = RadioButton4.Text
    arrAnimal(4) = RadioButton5.Text
    arrAnimal(5) = RadioButton6.Text
    lblDisplay.Text = "The " & txtReplace.Text & Chr(13) & " is Element [" & _
      (Array.IndexOf(arrAnimal, txtReplace.Text)) & "]" & Chr(13) & "in the Array"
    txtReplace.Text = ""
End Sub

Well, that’s it, in all its glory. I hope you have enjoyed these three tutorials on Fixed Arrays. I hope in the future to write other tutorials that will help beginners to better understand Visual Basic .NET.