form1.vb

Mastering VBNet Include Source Code

        Me.ClientSize = New System.Drawing.Size(702, 493)
        Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.Button1, Me.GlobeTree, Me.bttnExpandNode, Me.bttnDelNode, Me.GroupBox3, Me.GroupBox1})
        Me.Font = New System.Drawing.Font("Verdana", 8.25!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.Menu = Me.MainMenu1
        Me.Name = "Form1"
        Me.Text = "GLOBE"
        Me.GroupBox1.ResumeLayout(False)
        Me.GroupBox3.ResumeLayout(False)
        Me.ResumeLayout(False)

    End Sub

#End Region

    ' The project assumes that the continent names have been added to the TreeView control
    ' at design time. In the Form's Load event it adds country names under each continent
    ' and city names under each county 

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim GlobeNode As TreeNode
        Dim ContinentNode As TreeNode
        GlobeNode = GlobeTree.Nodes(0)
        Dim CountryNode As TreeNode
        For Each ContinentNode In GlobeNode.Nodes
            Select Case ContinentNode.Text

                Case "Europe"
                    CountryNode = ContinentNode.Nodes.Add("Germany")
                    CountryNode.Nodes.Add("Berlin")
                    CountryNode.Nodes.Add("Munich")
                    CountryNode.Nodes.Add("Bayreuth")
                    CountryNode.Nodes.Add("Frankfurt")
                    CountryNode = ContinentNode.Nodes.Add("France")
                    CountryNode.Nodes.Add("Paris")
                    CountryNode.Nodes.Add("Nice")
                    CountryNode.Nodes.Add("Lyon")
                    CountryNode = ContinentNode.Nodes.Add("Italy")
                    CountryNode.Nodes.Add("Rome")
                    CountryNode.Nodes.Add("Venice")
                    CountryNode.Nodes.Add("Napoli")
                    CountryNode.Nodes.Add("Florence")
                    CountryNode.Nodes.Add("Milan")
                    CountryNode = ContinentNode.Nodes.Add("Spain")
                    CountryNode.Nodes.Add("Madrid")
                    CountryNode.Nodes.Add("Barcelona")
                    CountryNode.Nodes.Add("Malaga")
                Case "Asia"
                    CountryNode = ContinentNode.Nodes.Add("China")
                    CountryNode.Nodes.Add("Bejing")
                    CountryNode.Nodes.Add("Nanjing")
                    CountryNode.Nodes.Add("Hong Kong")
                    CountryNode = ContinentNode.Nodes.Add("Japan")
                    CountryNode.Nodes.Add("Tokyo")
                    CountryNode.Nodes.Add("Osaka")
                    CountryNode.Nodes.Add("Kobe")
                    CountryNode.Nodes.Add("Kyotto")
                    CountryNode.Nodes.Add("Sapporo")
                Case "Africa"
                    CountryNode = ContinentNode.Nodes.Add("Egypt")
                    CountryNode.Nodes.Add("Cairo")
                    CountryNode.Nodes.Add("Alexandria")
                    CountryNode = ContinentNode.Nodes.Add("Libya")
                    CountryNode.Nodes.Add("Tripoli")
                    CountryNode = ContinentNode.Nodes.Add("South Africa")
                    CountryNode.Nodes.Add("Johannesburg")
                    CountryNode.Nodes.Add("Pretoria")
                    CountryNode = ContinentNode.Nodes.Add("Zimbabwe")
                    CountryNode.Nodes.Add("Harare")
                Case "Oceania"
                    CountryNode = ContinentNode.Nodes.Add("Australia")
                    CountryNode.Nodes.Add("Sidney")
                    CountryNode.Nodes.Add("Melbourne")
                    CountryNode.Nodes.Add("Adelaida")
                    CountryNode.Nodes.Add("Brisbane")
                    CountryNode.Nodes.Add("Canberra")
                    CountryNode = ContinentNode.Nodes.Add("New Zealand")
                    CountryNode.Nodes.Add("Wanaka")
                Case "N. America"
                    CountryNode = ContinentNode.Nodes.Add("USA")
                    CountryNode.Nodes.Add("New York")
                    CountryNode.Nodes.Add("Las Vegas")
                    CountryNode.Nodes.Add("Chicago")
                    CountryNode.Nodes.Add("Washington")
                    CountryNode.Nodes.Add("Durham")
                    CountryNode.Nodes.Add("San Francisco")
                    CountryNode = ContinentNode.Nodes.Add("Canada")
                    CountryNode.Nodes.Add("Toronto")
                    CountryNode.Nodes.Add("Vancouver")
                    CountryNode.Nodes.Add("Montreal")
                    CountryNode.Nodes.Add("Halifax")
                    CountryNode.Nodes.Add("Calgary")
                    CountryNode = ContinentNode.Nodes.Add("Mexico")
                    CountryNode.Nodes.Add("Mexico City")
                Case "S. America"
                    CountryNode = ContinentNode.Nodes.Add("Argentina")
                    CountryNode.Nodes.Add("Buenos Aires")
                    CountryNode = ContinentNode.Nodes.Add("Peru")
                    CountryNode.Nodes.Add("Lima")
                    CountryNode = ContinentNode.Nodes.Add("Colombia")
                    CountryNode.Nodes.Add("Bogota")
            End Select
        Next

    End Sub

    Private Sub bttnAddNode_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles bttnAddNode.Click
        Dim nd As TreeNode
        Dim Continents As TreeNode

        ' If the first TextBox contains a continent name, then search all continents to locate
        ' the specified continent.
        If txtContinent.Text.Trim <> "" Then
            Continents = GlobeTree.Nodes(0)
            Dim ContinentFound, CountryFound, CityFound As Boolean
            Dim ContinentNode, CountryNode, CityNode As TreeNode
            For Each nd In Continents.Nodes
                Console.WriteLine(nd.Text)
                If nd.Text.ToUpper = txtContinent.Text.ToUpper Then
                    ContinentFound = True
                    Exit For
                End If
            Next
            ' If the specified continent wasn't found, add it to the control
            If Not ContinentFound Then
                nd = Continents.Nodes.Add(txtContinent.Text)
            End If
            ContinentNode = nd
            ' If the second TextBox contains a country name, then search all countries under
            ' the current continent.
            If txtCountry.Text.Trim <> "" Then
                Dim Countries As TreeNode
                Countries = ContinentNode
                If Not Countries Is Nothing Then
                    For Each nd In Countries.Nodes
                        Console.WriteLine(nd.Text)
                        If nd.Text.ToUpper = txtCountry.Text.ToUpper Then
                            CountryFound = True
                            Exit For
                        End If
                    Next
                End If
                ' If the specified country wasn't found, add it under the current continent
                If Not CountryFound Then
                    nd = ContinentNode.Nodes.Add(txtCountry.Text)
                End If
                CountryNode = nd
                ' If the third TextBox contains a city name, then search all cities under 
                ' the current country
                    If txtCity.Text.Trim <> "" Then
                        Dim Cities As TreeNode
                        Cities = CountryNode
                        If Not Cities Is Nothing Then
                            For Each nd In Cities.Nodes
                                Console.WriteLine(nd.Text)
                                If nd.Text.ToUpper = txtCity.Text.ToUpper Then
                                    CityFound = True
                                    Exit For
                                End If
                            Next
                    End If
                    ' if the specified city wasn't found, add it under the current country
                    If Not CityFound Then
                        nd = CountryNode.Nodes.Add(txtCity.Text)
                    End If
                    CityNode = nd
                End If
            End If
        End If
    End Sub


    Private Sub bttnListContinents_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles bttnListContinents.Click
        Dim Nd As TreeNode, continentNode As TreeNode
        Dim continent As Integer, continents As Integer

        ListBox1.Items.Clear()
        Nd = GlobeTree.Nodes(0)
        continents = Nd.Nodes.Count
        continentNode = Nd.Nodes(0)
        For continent = 1 To continents
            ListBox1.Items.Add(continentNode.Text)
            continentNode = continentNode.NextNode
        Next
    End Sub

    Private Sub bttnListCountries_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles bttnListCountries.Click
        Dim Nd As TreeNode, CountryNode As TreeNode, ContinentNode As TreeNode
        Dim continent As Integer, continents As Integer
        Dim country As Integer, countries As Integer

        ListBox1.Items.Clear()
        Nd = GlobeTree.Nodes.Item(0)
        continents = Nd.Nodes.Count
        ContinentNode = Nd.Nodes(0)
        ' To locate all the countries, scan each continent ...
        For continent = 1 To continents
            countries = ContinentNode.Nodes.Count
            CountryNode = ContinentNode.Nodes(0)
            ' ... and all child nodes under the current continent 
            For country = 1 To countries
                ListBox1.Items.Add(CountryNode.Text)
                CountryNode = CountryNode.NextNode
            Next
            ContinentNode = ContinentNode.NextNode
        Next
    End Sub

    Private Sub bttnListCities_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles bttnListCities.Click
        Dim Nd As TreeNode, countryNode As TreeNode, continentNode As TreeNode, cityNode As TreeNode
        Dim continent As Integer, continents As Integer
        Dim country As Integer, countries As Integer
        Dim city As Integer, cities As Integer

        ListBox1.Items.Clear()
        Nd = GlobeTree.Nodes(0)
        continents = Nd.Nodes.Count
        continentNode = Nd.Nodes(0)
        ' To locate all the cities, scan each continent ... 
        For continent = 1 To continents
            countries = continentNode.Nodes.Count
            countryNode = continentNode.Nodes(0)
            ' ... all the child nodes under the current continent ...
            For country = 1 To countries
                cities = countryNode.Nodes.Count
                cityNode = countryNode.Nodes(0)
                ' ... and all the child nodes under the current city
                For city = 1 To cities
                    ListBox1.Items.Add(cityNode.Text)
                    cityNode = cityNode.NextNode
                Next
                countryNode = countryNode.NextNode
            Next
            continentNode = continentNode.NextNode
        Next
    End Sub