Private Sub WhatIsChecked_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles WhatIsChecked.Click
    ' Display in a message box all the items that are checked.
    Dim indexChecked As Integer
    Dim itemChecked As Object
    Const quote As String = """"

    ' First show the index and check state of all selected items.
    For Each indexChecked In CheckedListBox1.CheckedIndices
        ' The indexChecked variable contains the index of the item.
        MessageBox.Show("Index#: " + indexChecked.ToString() + ", is checked. Checked state is:" + _
                        CheckedListBox1.GetItemCheckState(indexChecked).ToString() + ".")
    Next

    ' Next show the object title and check state for each item selected.
    For Each itemChecked In CheckedListBox1.CheckedItems

        ' Use the IndexOf method to get the index of an item.
        MessageBox.Show("Item with title: " + quote + itemChecked.ToString() + quote + _
                        ", is checked. Checked state is: " + _
                        CheckedListBox1.GetItemCheckState(CheckedListBox1.Items.IndexOf(itemChecked)).ToString() + ".")
    Next

End Sub

' 导入命名空间
Imports System
Imports System.Data
Imports System.Windows.Forms
Imports System.Drawing

Public Class MainClass
    
    Shared Sub Main()
        Dim form1 As Form = New Form1
        Application.Run(form1)
    End Sub
End Class


Public Class Form1
    Private Sub Form1_Load(ByVal sender As System.Object, _
     ByVal e As System.EventArgs) Handles MyBase.Load
        clbStudents.Items.Add(New Student("A", "A"), True)
        clbStudents.Items.Add(New Student("B", "B"), False)
        clbStudents.Items.Add(New Student("C", "C"), _
            CheckState.Indeterminate)
    End Sub

    Private Sub btnListSelections_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnListSelections.Click
        Dim checked_items As CheckedListBox.CheckedItemCollection = clbStudents.CheckedItems
        Dim txt As String = "     Selected Students:" & vbCrLf
        For Each item As Object In checked_items
            txt &= item.ToString & vbCrLf
        Next item
        MessageBox.Show(txt)
    End Sub
End Class

Public Class Student
    Public FirstName As String
    Public LastName As String

    Public Sub New(ByVal first_name As String, ByVal last_name As String)
        FirstName = first_name
        LastName = last_name
    End Sub

    Public Overrides Function ToString() As String
        Return FirstName & " " & LastName
    End Function
End Class


<Global.Microsoft.VisualBasic.CompilerServices.DesignerGenerated()> _
Partial Public Class Form1
    Inherits System.Windows.Forms.Form

    'Form overrides dispose to clean up the component list.
    <System.Diagnostics.DebuggerNonUserCode()> _
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing AndAlso components IsNot Nothing Then
            components.Dispose()
        End If
        MyBase.Dispose(disposing)
    End Sub

    'Required by the Windows Form Designer
    Private components As System.ComponentModel.IContainer

    'NOTE: The following procedure is required by the Windows Form Designer
    'It can be modified using the Windows Form Designer.  
    'Do not modify it using the code editor.
    <System.Diagnostics.DebuggerStepThrough()> _
    Private Sub InitializeComponent()
        Me.clbStudents = New System.Windows.Forms.CheckedListBox
        Me.btnListSelections = New System.Windows.Forms.Button
        Me.SuspendLayout()
        '
        'clbStudents
        '
        Me.clbStudents.FormattingEnabled = True
        Me.clbStudents.Location = New System.Drawing.Point(8, 8)
        Me.clbStudents.Name = "clbStudents"
        Me.clbStudents.Size = New System.Drawing.Size(160, 123)
        Me.clbStudents.TabIndex = 0
        '
        'btnListSelections
        '
        Me.btnListSelections.Location = New System.Drawing.Point(8, 152)
        Me.btnListSelections.Name = "btnListSelections"
        Me.btnListSelections.Size = New System.Drawing.Size(160, 23)
        Me.btnListSelections.TabIndex = 1
        Me.btnListSelections.Text = "List Selections"
        '
        'Form1
        '
        Me.AutoScaleDimensions = New System.Drawing.SizeF(6.0!, 13.0!)
        Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font
        Me.ClientSize = New System.Drawing.Size(180, 187)
        Me.Controls.Add(Me.btnListSelections)
        Me.Controls.Add(Me.clbStudents)
        Me.Name = "Form1"
        Me.Text = "UseCheckedListBox"
        Me.ResumeLayout(False)

    End Sub
    Friend WithEvents clbStudents As System.Windows.Forms.CheckedListBox
    Friend WithEvents btnListSelections As System.Windows.Forms.Button

End Class