Public Class frmMain
    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 MainMenu1 As System.Windows.Forms.MainMenu
    Friend WithEvents mnBasic As System.Windows.Forms.MenuItem
    Friend WithEvents mnClass As System.Windows.Forms.MenuItem
    Friend WithEvents mnStudent As System.Windows.Forms.MenuItem
    Friend WithEvents mnSubject As System.Windows.Forms.MenuItem
    Friend WithEvents mnTeach As System.Windows.Forms.MenuItem
    Friend WithEvents mnSelect As System.Windows.Forms.MenuItem
    Friend WithEvents mnCourse As System.Windows.Forms.MenuItem
    Friend WithEvents mnResult As System.Windows.Forms.MenuItem
    Friend WithEvents mnPrint As System.Windows.Forms.MenuItem
    Friend WithEvents mnExit As System.Windows.Forms.MenuItem
    Friend WithEvents mnReport As System.Windows.Forms.MenuItem
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Dim resources As System.Resources.ResourceManager = New System.Resources.ResourceManager(GetType(frmMain))
        Me.MainMenu1 = New System.Windows.Forms.MainMenu
        Me.mnBasic = New System.Windows.Forms.MenuItem
        Me.mnClass = New System.Windows.Forms.MenuItem
        Me.mnStudent = New System.Windows.Forms.MenuItem
        Me.mnSubject = New System.Windows.Forms.MenuItem
        Me.mnTeach = New System.Windows.Forms.MenuItem
        Me.mnSelect = New System.Windows.Forms.MenuItem
        Me.mnCourse = New System.Windows.Forms.MenuItem
        Me.mnResult = New System.Windows.Forms.MenuItem
        Me.mnPrint = New System.Windows.Forms.MenuItem
        Me.mnReport = New System.Windows.Forms.MenuItem
        Me.mnExit = New System.Windows.Forms.MenuItem
        '
        'MainMenu1
        '
        Me.MainMenu1.MenuItems.AddRange(New System.Windows.Forms.MenuItem() {Me.mnBasic, Me.mnTeach, Me.mnPrint, Me.mnExit})
        '
        'mnBasic
        '
        Me.mnBasic.Index = 0
        Me.mnBasic.MenuItems.AddRange(New System.Windows.Forms.MenuItem() {Me.mnClass, Me.mnStudent, Me.mnSubject})
        Me.mnBasic.Text = "基礎維護(&W)"
        '
        'mnClass
        '
        Me.mnClass.Index = 0
        Me.mnClass.Text = "班級信息維護(&X)"
        '
        'mnStudent
        '
        Me.mnStudent.Index = 1
        Me.mnStudent.Text = "學生信息維護(&Y)"
        '
        'mnSubject
        '
        Me.mnSubject.Index = 2
        Me.mnSubject.Text = "課程信息維護(&Z)"
        '
        'mnTeach
        '
        Me.mnTeach.Index = 1
        Me.mnTeach.MenuItems.AddRange(New System.Windows.Forms.MenuItem() {Me.mnSelect, Me.mnCourse, Me.mnResult})
        Me.mnTeach.Text = "教學管理(&X)"
        '
        'mnSelect
        '
        Me.mnSelect.Index = 0
        Me.mnSelect.Text = "學生選課(&X)"
        '
        'mnCourse
        '
        Me.mnCourse.Index = 1
        Me.mnCourse.Text = "課表查詢(&Y)"
        '
        'mnResult
        '
        Me.mnResult.Index = 2
        Me.mnResult.Text = "成績輸入(&Z)"
        '
        'mnPrint
        '
        Me.mnPrint.Index = 2
        Me.mnPrint.MenuItems.AddRange(New System.Windows.Forms.MenuItem() {Me.mnReport})
        Me.mnPrint.Text = "報表統計(&Y)"
        '
        'mnReport
        '
        Me.mnReport.Index = 0
        Me.mnReport.Text = "打印成績單(&Z)"
        '
        'mnExit
        '
        Me.mnExit.Index = 3
        Me.mnExit.Text = "退出系統(&Z)"
        '
        'frmMain
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(6, 14)
        Me.ClientSize = New System.Drawing.Size(416, 235)
        Me.Icon = CType(resources.GetObject("$this.Icon"), System.Drawing.Icon)
        Me.IsMdiContainer = True
        Me.Menu = Me.MainMenu1
        Me.Name = "frmMain"
        Me.Text = "EIS教務管理系統"

    End Sub

#End Region
    Private Function GetInstanceState(ByVal name As String) As Boolean
        '獲得frmMain窗體的子窗體的數量
        Dim i As Integer = Me.MdiChildren.Length
        '循環判斷是否有名為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 mnClass_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles mnClass.Click
        If GetInstanceState("frmClass") Then
            Exit Sub
        End If
        Dim childFrm As frmClass = New frmClass
        childFrm.MdiParent = Me
        childFrm.Show()
    End Sub

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

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

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

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

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

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

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

    End Sub
End Class