Public Class frmMain
    Inherits System.Windows.Forms.Form

#Region " Windows 窗體設(shè)計器生成的代碼 "

    Public Sub New()
        MyBase.New()

        '該調(diào)用是 Windows 窗體設(shè)計器所必需的。
        InitializeComponent()

        '在 InitializeComponent() 調(diào)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(shè)計器所必需的
    Private components As System.ComponentModel.IContainer

    '注意: 以下過程是 Windows 窗體設(shè)計器所必需的
    '可以使用 Windows 窗體設(shè)計器修改此過程。
    '不要使用代碼編輯器修改它。
    Friend WithEvents StatusBar As System.Windows.Forms.StatusBar
    Friend WithEvents MainMenu1 As System.Windows.Forms.MainMenu
    Friend WithEvents mnReader As System.Windows.Forms.MenuItem
    Friend WithEvents mnReaderType As System.Windows.Forms.MenuItem
    Friend WithEvents mnReaderDoc As System.Windows.Forms.MenuItem
    Friend WithEvents mnBook As System.Windows.Forms.MenuItem
    Friend WithEvents mnBookType As System.Windows.Forms.MenuItem
    Friend WithEvents mnBookDoc As System.Windows.Forms.MenuItem
    Friend WithEvents mnManage As System.Windows.Forms.MenuItem
    Friend WithEvents mnBuy As System.Windows.Forms.MenuItem
    Friend WithEvents mnBorrow As System.Windows.Forms.MenuItem
    Friend WithEvents mnReturn As System.Windows.Forms.MenuItem
    Friend WithEvents mnList As System.Windows.Forms.MenuItem
    Friend WithEvents mnMoney As System.Windows.Forms.MenuItem
    Friend WithEvents mnExit As System.Windows.Forms.MenuItem
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Dim resources As System.Resources.ResourceManager = New System.Resources.ResourceManager(GetType(frmMain))
        Me.StatusBar = New System.Windows.Forms.StatusBar
        Me.MainMenu1 = New System.Windows.Forms.MainMenu
        Me.mnReader = New System.Windows.Forms.MenuItem
        Me.mnReaderType = New System.Windows.Forms.MenuItem
        Me.mnReaderDoc = New System.Windows.Forms.MenuItem
        Me.mnBook = New System.Windows.Forms.MenuItem
        Me.mnBookType = New System.Windows.Forms.MenuItem
        Me.mnBookDoc = New System.Windows.Forms.MenuItem
        Me.mnManage = New System.Windows.Forms.MenuItem
        Me.mnBuy = New System.Windows.Forms.MenuItem
        Me.mnBorrow = New System.Windows.Forms.MenuItem
        Me.mnReturn = New System.Windows.Forms.MenuItem
        Me.mnList = New System.Windows.Forms.MenuItem
        Me.mnMoney = New System.Windows.Forms.MenuItem
        Me.mnExit = New System.Windows.Forms.MenuItem
        Me.SuspendLayout()
        '
        'StatusBar
        '
        Me.StatusBar.Location = New System.Drawing.Point(0, 257)
        Me.StatusBar.Name = "StatusBar"
        Me.StatusBar.Size = New System.Drawing.Size(488, 16)
        Me.StatusBar.SizingGrip = False
        Me.StatusBar.TabIndex = 3
        Me.StatusBar.Text = "數(shù)據(jù)庫開發(fā)經(jīng)典實例解析  清華大學出版社 用戶登陸功能和權(quán)限管理功能參考進銷存實例"
        '
        'MainMenu1
        '
        Me.MainMenu1.MenuItems.AddRange(New System.Windows.Forms.MenuItem() {Me.mnReader, Me.mnBook, Me.mnManage, Me.mnExit})
        '
        'mnReader
        '
        Me.mnReader.Index = 0
        Me.mnReader.MenuItems.AddRange(New System.Windows.Forms.MenuItem() {Me.mnReaderType, Me.mnReaderDoc})
        Me.mnReader.Text = "讀者管理(&W)"
        '
        'mnReaderType
        '
        Me.mnReaderType.Index = 0
        Me.mnReaderType.Text = "讀者類別設(shè)置(&Y)"
        '
        'mnReaderDoc
        '
        Me.mnReaderDoc.Index = 1
        Me.mnReaderDoc.Text = "讀者檔案管理(&Z)"
        '
        'mnBook
        '
        Me.mnBook.Index = 1
        Me.mnBook.MenuItems.AddRange(New System.Windows.Forms.MenuItem() {Me.mnBookType, Me.mnBookDoc})
        Me.mnBook.Text = "圖書管理(&X)"
        '
        'mnBookType
        '
        Me.mnBookType.Index = 0
        Me.mnBookType.Text = "圖書類別設(shè)置(&Y)"
        '
        'mnBookDoc
        '
        Me.mnBookDoc.Index = 1
        Me.mnBookDoc.Text = "圖書檔案管理(&Z)"
        '
        'mnManage
        '
        Me.mnManage.Index = 2
        Me.mnManage.MenuItems.AddRange(New System.Windows.Forms.MenuItem() {Me.mnBuy, Me.mnBorrow, Me.mnReturn, Me.mnList, Me.mnMoney})
        Me.mnManage.Text = "流通管理(&Y)"
        '
        'mnBuy
        '
        Me.mnBuy.Index = 0
        Me.mnBuy.Text = "圖書征訂(&V)"
        '
        'mnBorrow
        '
        Me.mnBorrow.Index = 1
        Me.mnBorrow.Text = "圖書借閱(&W)"
        '
        'mnReturn
        '
        Me.mnReturn.Index = 2
        Me.mnReturn.Text = "圖書歸還(&X)"
        '
        'mnList
        '
        Me.mnList.Index = 3
        Me.mnList.Text = "逾期清單(&Y)"
        '
        'mnMoney
        '
        Me.mnMoney.Index = 4
        Me.mnMoney.Text = "圖書罰款(&Z)"
        '
        'mnExit
        '
        Me.mnExit.Index = 3
        Me.mnExit.Text = "退出系統(tǒng)(&Z)"
        '
        'frmMain
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(6, 14)
        Me.ClientSize = New System.Drawing.Size(488, 273)
        Me.Controls.Add(Me.StatusBar)
        Me.Icon = CType(resources.GetObject("$this.Icon"), System.Drawing.Icon)
        Me.IsMdiContainer = True
        Me.Menu = Me.MainMenu1
        Me.Name = "frmMain"
        Me.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen
        Me.Text = "圖書管理系統(tǒng)"
        Me.ResumeLayout(False)

    End Sub

#End Region
    Private Function GetInstanceState(ByVal name As String) As Boolean
        '獲得frmMain窗體的子窗體的數(shù)量
        Dim i As Integer = Me.MdiChildren.Length
        '循環(huán)判斷是否有名為name的子窗體實例
        For i = 0 To Me.MdiChildren.Length - 1
            If Me.MdiChildren(i).Name = name Then
                '存在名為name的子窗體，是子窗體獲得焦點并返回True
                Me.MdiChildren(i).Focus()
                Return True
            End If
        Next
        '不存在名為Name的子窗體False
        Return False
    End Function


    Private Sub mnReaderType_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles mnReaderType.Click
        If GetInstanceState("frmReaderType") Then
            Exit Sub
        End If
        Dim childFrm As frmReaderType = New frmReaderType
        childFrm.MdiParent = Me
        childFrm.Show()
    End Sub

    Private Sub mnReaderDoc_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles mnReaderDoc.Click
        If GetInstanceState("frmReaderDoc") Then
            Exit Sub
        End If
        Dim childFrm As frmReaderDoc = New frmReaderDoc
        childFrm.MdiParent = Me
        childFrm.Show()
    End Sub

    Private Sub mnBookType_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles mnBookType.Click
        If GetInstanceState("frmBookType") Then
            Exit Sub
        End If
        Dim childFrm As frmBookType = New frmBookType
        childFrm.MdiParent = Me
        childFrm.Show()
    End Sub

    Private Sub mnBookDoc_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles mnBookDoc.Click
        If GetInstanceState("frmBookDoc") Then
            Exit Sub
        End If
        Dim childFrm As frmBookDoc = New frmBookDoc
        childFrm.MdiParent = Me
        childFrm.Show()
    End Sub

    Private Sub mnBuy_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles mnBuy.Click
        If GetInstanceState("frmBuyBook") Then
            Exit Sub
        End If
        Dim childFrm As frmBuyBook = New frmBuyBook
        childFrm.MdiParent = Me
        childFrm.Show()

    End Sub

    Private Sub mnBorrow_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles mnBorrow.Click
        If GetInstanceState("frmBorrow") Then
            Exit Sub
        End If
        Dim childFrm As frmBorrow = New frmBorrow
        childFrm.MdiParent = Me
        childFrm.Show()
    End Sub

    Private Sub mnList_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles mnList.Click
        If GetInstanceState("frmList") Then
            Exit Sub
        End If
        Dim childFrm As frmList = New frmList
        childFrm.MdiParent = Me
        childFrm.Show()
    End Sub

    Private Sub mnMoney_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles mnMoney.Click
        If GetInstanceState("frmMoney") Then
            Exit Sub
        End If
        Dim childFrm As frmMoney = New frmMoney
        childFrm.MdiParent = Me
        childFrm.Show()
    End Sub

    Private Sub mnReturn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles mnReturn.Click
        If GetInstanceState("frmReturn") Then
            Exit Sub
        End If
        Dim childFrm As frmReturn = New frmReturn
        childFrm.MdiParent = Me
        childFrm.Show()
    End Sub

    Private Sub mnExit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles mnExit.Click
        Application.Exit()
    End Sub
End Class