defaultvb.aspx.vb

Telerik是很大的第三方软件制造商

Imports System
Imports System.Data
Imports System.Data.OleDb
Imports Telerik.QuickStart
Imports Telerik.WebControls


Namespace Telerik.ComboboxExamplesVB.MultipleComboBoxes
   
   '/ <summary>
   '/ Summary description for _Default.
   '/ </summary>
   Public Class DefaultVB
      Inherits XhtmlPage
      Protected WithEvents RadComboBox2 As RadComboBox
      Protected WithEvents RadComboBox3 As RadComboBox
      Protected WithEvents RadComboBox1 As RadComboBox
      
      
      Private Sub Page_Load(sender As Object, e As EventArgs) Handles MyBase.Load
         If Not Page.IsPostBack Then
            LoadContinents()
         End If
      End Sub 'Page_Load
      Protected Overrides Sub OnInit(e As EventArgs)
         '
         ' CODEGEN: This call is required by the ASP.NET Web Form Designer.
         '
         InitializeComponent()
         MyBase.OnInit(e)
      End Sub 'OnInit
      
      
      '/		Required method for Designer support - do not modify
      '/		the contents of this method with the code editor.
      '/ </summary>
      Private Sub InitializeComponent()
      End Sub 'InitializeComponent
      Private Sub LoadContinents()
         Dim path As String = Server.MapPath("~/Combobox/Data/Countries.mdb")
         Dim dbCon As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + path)
         dbCon.Open()
         
         Dim adapter As New OleDbDataAdapter("SELECT * FROM Continents", dbCon)
         Dim dt As New DataTable()
         adapter.Fill(dt)
         dbCon.Close()
         
         RadComboBox1.DataTextField = "Name"
         RadComboBox1.DataValueField = "ID"
         RadComboBox1.DataSource = dt
         RadComboBox1.DataBind()
         
         RadComboBox1.Items.Insert(0, New RadComboBoxItem("- Select a continent -"))
         
         Dim item As RadComboBoxItem
         For Each item In  RadComboBox1.Items
            item.ToolTip = item.Text
         Next item
      End Sub 'LoadContinents
      
      
      Private Sub LoadCountries(continentID As String)
         Dim path As String = Server.MapPath("~/Combobox/Data/Countries.mdb")
         Dim dbCon As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + path)
         dbCon.Open()
         
         Dim adapter As New OleDbDataAdapter("SELECT * FROM Countries WHERE ContinentID=" + continentID, dbCon)
         Dim dt As New DataTable()
         adapter.Fill(dt)
         dbCon.Close()
         
         RadComboBox2.DataTextField = "Name"
         RadComboBox2.DataValueField = "ID"
         RadComboBox2.DataSource = dt
         RadComboBox2.DataBind()
         
         Dim item As RadComboBoxItem
         For Each item In  RadComboBox2.Items
            item.ToolTip = item.Text
         Next item
      End Sub 'LoadCountries
      
      
      Private Sub LoadCities(countryID As String)
         Dim path As String = Server.MapPath("~/Combobox/Data/Countries.mdb")
         Dim dbCon As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + path)
         dbCon.Open()
         
         Dim adapter As New OleDbDataAdapter("SELECT * FROM Cities WHERE CountryID=" + countryID, dbCon)
         Dim dt As New DataTable()
         adapter.Fill(dt)
         dbCon.Close()
         
         RadComboBox3.DataTextField = "Name"
         RadComboBox3.DataValueField = "ID"
         RadComboBox3.DataSource = dt
         RadComboBox3.DataBind()
         
         Dim item As RadComboBoxItem
         For Each item In  RadComboBox3.Items
            item.ToolTip = item.Text
         Next item
      End Sub 'LoadCities
      
      
      Private Sub RadComboBox1_ItemsRequested(o As Object, e As RadComboBoxItemsRequestedEventArgs) Handles RadComboBox1.ItemsRequested
         LoadContinents()
      End Sub 'RadComboBox1_ItemsRequested
      
      
      Private Sub RadComboBox2_ItemsRequested(o As Object, e As RadComboBoxItemsRequestedEventArgs) Handles RadComboBox2.ItemsRequested
         LoadCountries(e.Text)
      End Sub 'RadComboBox2_ItemsRequested
      
      
      Private Sub RadComboBox3_ItemsRequested(o As Object, e As RadComboBoxItemsRequestedEventArgs) Handles RadComboBox3.ItemsRequested
         LoadCities(e.Text)
      End Sub 'RadComboBox3_ItemsRequested
   End Class 'DefaultVB
End Namespace 'Telerik.ComboboxExamplesVB.MultipleComboBoxes