Public Class Form1
    Inherits System.Windows.Forms.Form

#Region " Windows 窗體設計器生成的代碼 "

    Public Sub New()
        MyBase.New()

        '該調用是 Windows 窗體設計器所必需的。
        InitializeComponent()

        '在 InitializeComponent() 調用之后添加任何初始化

    End Sub

    '窗體重寫 dispose 以清理組件列表。
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub

    'Windows 窗體設計器所必需的
    Private components As System.ComponentModel.IContainer

    '注意: 以下過程是 Windows 窗體設計器所必需的
    '可以使用 Windows 窗體設計器修改此過程。
    '不要使用代碼編輯器修改它。
    Friend WithEvents Label1 As System.Windows.Forms.Label
    Friend WithEvents LB1 As System.Windows.Forms.ListBox
    Friend WithEvents LB2 As System.Windows.Forms.ListBox
    Friend WithEvents Button1 As System.Windows.Forms.Button
    Friend WithEvents TextBox1 As System.Windows.Forms.TextBox
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.Label1 = New System.Windows.Forms.Label
        Me.LB1 = New System.Windows.Forms.ListBox
        Me.LB2 = New System.Windows.Forms.ListBox
        Me.Button1 = New System.Windows.Forms.Button
        Me.TextBox1 = New System.Windows.Forms.TextBox
        Me.SuspendLayout()
        '
        'Label1
        '
        Me.Label1.Location = New System.Drawing.Point(16, 8)
        Me.Label1.Name = "Label1"
        Me.Label1.Size = New System.Drawing.Size(168, 32)
        Me.Label1.TabIndex = 0
        Me.Label1.Text = "選中城市后請雙擊"
        '
        'LB1
        '
        Me.LB1.ItemHeight = 12
        Me.LB1.Location = New System.Drawing.Point(8, 48)
        Me.LB1.Name = "LB1"
        Me.LB1.Size = New System.Drawing.Size(176, 208)
        Me.LB1.TabIndex = 1
        '
        'LB2
        '
        Me.LB2.ItemHeight = 12
        Me.LB2.Location = New System.Drawing.Point(248, 48)
        Me.LB2.Name = "LB2"
        Me.LB2.Size = New System.Drawing.Size(168, 208)
        Me.LB2.TabIndex = 2
        '
        'Button1
        '
        Me.Button1.Location = New System.Drawing.Point(24, 296)
        Me.Button1.Name = "Button1"
        Me.Button1.Size = New System.Drawing.Size(120, 24)
        Me.Button1.TabIndex = 3
        Me.Button1.Text = "添加"
        '
        'TextBox1
        '
        Me.TextBox1.Location = New System.Drawing.Point(176, 296)
        Me.TextBox1.Name = "TextBox1"
        Me.TextBox1.Size = New System.Drawing.Size(160, 21)
        Me.TextBox1.TabIndex = 4
        Me.TextBox1.Text = ""
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(6, 14)
        Me.ClientSize = New System.Drawing.Size(424, 374)
        Me.Controls.Add(Me.TextBox1)
        Me.Controls.Add(Me.Button1)
        Me.Controls.Add(Me.LB2)
        Me.Controls.Add(Me.LB1)
        Me.Controls.Add(Me.Label1)
        Me.Name = "Form1"
        Me.Text = "Form1"
        Me.ResumeLayout(False)

    End Sub

#End Region

   
   

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        LB1.Items.Add("北京")
        LB1.Items.Add("深圳")
        LB1.Items.Add("昆明")
        LB1.Items.Add("重慶")
        LB1.Items.Add("天津")
        LB1.Items.Add("上海")

    End Sub




    Private Sub LB1_DoubleClick(ByVal sender As Object, ByVal e As System.EventArgs) Handles LB1.DoubleClick
        If LB1.SelectedIndex >= 0 Then
            LB2.Items.Add(LB1.SelectedItem.ToString)
            LB1.Items.Remove(LB1.SelectedItem.ToString)
            LB1.SelectedIndex = -1
        Else
            MessageBox.Show("請選擇一個城市", "錯誤")
        End If
    End Sub

    Private Sub LB2_DoubleClick(ByVal sender As Object, ByVal e As System.EventArgs) Handles LB2.DoubleClick
        If LB2.SelectedIndex >= 0 Then
            LB1.Items.Add(LB2.SelectedItem.ToString)
            LB2.Items.RemoveAt(LB2.SelectedIndex)
            LB2.SelectedIndex = -1
        Else
            MessageBox.Show("請選擇一個城市", "錯誤")
        End If
    End Sub

    

    Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
        If TextBox1.Text = "" Then
            Button1.Enabled = False
        Else
            Button1.Enabled = True
        End If
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        If TextBox1.Text <> "" Then
            If LB1.Items.Contains(TextBox1.Text) = False Then
                LB1.Items.Add(TextBox1.Text)
                TextBox1.Text = ""
            End If
        End If
    End Sub
End Class