Lesson 21: Mastering Checkbox Controls in VB2022

' Create a new checkbox dynamically
Dim chkNew As New CheckBox()
chkNew.Text = "Enable Feature"
chkNew.AutoSize = True
chkNew.Location = New Point(20, 50)
Me.Controls.Add(chkNew)

Private Sub BtnCal_Click(sender As Object, e As EventArgs) Handles BtnCal.Click
    ' Define item prices
    Const LX As Integer = 100
    Const BN As Integer = 500
    Const SD As Integer = 200
    
    Dim sum As Integer = 0
    
    ' Check each checkbox and add price if checked
    If CheckBox1.Checked Then sum += LX
    If CheckBox2.Checked Then sum += BN
    If CheckBox3.Checked Then sum += SD
    
    ' Display total as currency
    LblTotal.Text = sum.ToString("c")
End Sub

Private Sub ChkBold_CheckedChanged(sender As Object, e As EventArgs) Handles ChkBold.CheckedChanged
    If ChkBold.Checked Then
        LblDisplay.Font = New Font(LblDisplay.Font, LblDisplay.Font.Style Or FontStyle.Bold)
    Else
        LblDisplay.Font = New Font(LblDisplay.Font, LblDisplay.Font.Style And Not FontStyle.Bold)
    End If
End Sub

Private Sub ChkItalic_CheckedChanged(sender As Object, e As EventArgs) Handles ChkItalic.CheckedChanged
    If ChkItalic.Checked Then
        LblDisplay.Font = New Font(LblDisplay.Font, LblDisplay.Font.Style Or FontStyle.Italic)
    Else
        LblDisplay.Font = New Font(LblDisplay.Font, LblDisplay.Font.Style And Not FontStyle.Italic)
    End If
End Sub

Private Sub BtnAdd_Click(sender As Object, e As EventArgs) Handles BtnAdd.Click
    If Not String.IsNullOrEmpty(TxtTask.Text) Then
        Dim newCheckbox As New CheckBox()
        newCheckbox.Text = TxtTask.Text
        newCheckbox.AutoSize = True
        newCheckbox.Font = New Font("Segoe UI", 10)
        
        ' Add completed style handler
        AddHandler newCheckbox.CheckedChanged, AddressOf Task_CheckedChanged
        
        ' Add to flow layout panel
        FlowLayoutPanel1.Controls.Add(newCheckbox)
        TxtTask.Clear()
    End If
End Sub

Private Sub Task_CheckedChanged(sender As Object, e EventArgs)
    Dim taskCheckbox As CheckBox = CType(sender, CheckBox)
    If taskCheckbox.Checked Then
        ' Apply strike-through for completed tasks
        taskCheckbox.Font = New Font(taskCheckbox.Font, FontStyle.Strikeout)
        taskCheckbox.ForeColor = Color.Gray
    Else
        ' Revert to normal style
        taskCheckbox.Font = New Font(taskCheckbox.Font, FontStyle.Regular)
        taskCheckbox.ForeColor = Color.Black
    End If
End Sub

Private Sub BtnSubscribe_Click(sender As Object, e As EventArgs) Handles BtnSubscribe.Click
    Dim message As String = "Subscription Details:" & Environment.NewLine
    message &= "Email: " & TxtEmail.Text & Environment.NewLine
    
    ' Add selected categories
    Dim categories As New List(Of String)()
    If ChkNews.Checked Then categories.Add("News")
    If ChkTech.Checked Then categories.Add("Technology")
    
    message &= "Categories: " & String.Join(", ", categories)
    
    MessageBox.Show(message, "Subscription Confirmation")
End Sub