form1.vb

来自「清华大学出版社出版的 移动应用开发宝典 张大威（2008）的附书源代码」· VB 代码 · 共 260 行

Imports System
Imports System.Drawing
Imports System.Collections
Imports System.Windows.Forms
Imports System.Data
Imports System.Data.SqlServerCe
Imports System.Data.Common

Namespace Merge_Repl

    '' <summary>
    '' Summary description for Form1.
    '' </summary>
    Public Class FormMR
        Inherits System.Windows.Forms.Form

        Private buttonAddCar As System.Windows.Forms.Button
        Private textBoxLocation As System.Windows.Forms.TextBox
        Private label2 As System.Windows.Forms.Label
        Private textBoxReg As System.Windows.Forms.TextBox
        Private label1 As System.Windows.Forms.Label
        Private buttonMerge As System.Windows.Forms.Button
        Private dataGridCars As System.Windows.Forms.DataGrid
        Private mainMenu1 As System.Windows.Forms.MainMenu
        Private carsBindingSource As BindingSource
        Private components As System.ComponentModel.IContainer

        Private dsCars As DataSet
        Private daCars As SqlCeDataAdapter
        Private cnCars As SqlCeConnection

        Public Sub New()
            ''
            '' Required for Windows Form Designer support
            ''
            InitializeComponent()
        End Sub

        '' <summary>
        '' Clean up any resources being used.
        '' </summary>
        Protected Overrides Sub Dispose(ByVal disposing As Boolean)
            MyBase.Dispose(disposing)
        End Sub

#Region "Windows Form Designer generated code"
        '' <summary>
        '' Required method for Designer support - do not modify
        '' the contents of me method with the code editor.
        '' </summary>
        Private Sub InitializeComponent()

            Me.components = New System.ComponentModel.Container()
            Me.mainMenu1 = New System.Windows.Forms.MainMenu()
            Me.buttonAddCar = New System.Windows.Forms.Button()
            Me.textBoxLocation = New System.Windows.Forms.TextBox()
            Me.label2 = New System.Windows.Forms.Label()
            Me.textBoxReg = New System.Windows.Forms.TextBox()
            Me.label1 = New System.Windows.Forms.Label()
            Me.buttonMerge = New System.Windows.Forms.Button()
            Me.carsBindingSource = New System.Windows.Forms.BindingSource(Me.components)
            Me.dataGridCars = New System.Windows.Forms.DataGrid()
            Me.SuspendLayout()
            '' 
            '' buttonAddCar
            '' 
            Me.buttonAddCar.Location = New System.Drawing.Point(64, 184)
            Me.buttonAddCar.Name = "buttonAddCar"
            Me.buttonAddCar.Size = New System.Drawing.Size(64, 20)
            Me.buttonAddCar.TabIndex = 2
            Me.buttonAddCar.Text = "Add"
            AddHandler Me.buttonAddCar.Click, AddressOf Me.buttonAddCar_Click
            '' 
            '' textBoxLocation
            '' 
            Me.textBoxLocation.Location = New System.Drawing.Point(64, 152)
            Me.textBoxLocation.Name = "textBoxLocation"
            Me.textBoxLocation.Size = New System.Drawing.Size(160, 21)
            Me.textBoxLocation.TabIndex = 3
            '' 
            '' label2
            '' 
            Me.label2.Location = New System.Drawing.Point(8, 160)
            Me.label2.Name = "label2"
            Me.label2.Size = New System.Drawing.Size(64, 12)
            Me.label2.Text = "Location:"
            '' 
            '' textBoxReg
            '' 
            Me.textBoxReg.Location = New System.Drawing.Point(64, 128)
            Me.textBoxReg.Name = "textBoxReg"
            Me.textBoxReg.Size = New System.Drawing.Size(64, 21)
            Me.textBoxReg.TabIndex = 5
            '' 
            '' label1
            '' 
            Me.label1.Location = New System.Drawing.Point(8, 136)
            Me.label1.Name = "label1"
            Me.label1.Size = New System.Drawing.Size(32, 16)
            Me.label1.Text = "Reg:"
            '' 
            '' buttonMerge
            '' 
            Me.buttonMerge.Location = New System.Drawing.Point(64, 224)
            Me.buttonMerge.Name = "buttonMerge"
            Me.buttonMerge.Size = New System.Drawing.Size(88, 24)
            Me.buttonMerge.TabIndex = 1
            Me.buttonMerge.Text = "Merge"
            AddHandler Me.buttonMerge.Click, AddressOf Me.buttonMerge_Click
            '' 
            '' dataGridCars
            '' 
            Me.dataGridCars.DataSource = Me.carsBindingSource
            Me.dataGridCars.Location = New System.Drawing.Point(8, 8)
            Me.dataGridCars.Name = "dataGridCars"
            Me.dataGridCars.Size = New System.Drawing.Size(224, 112)
            Me.dataGridCars.TabIndex = 0
            '' 
            '' FormMR
            '' 
            Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Inherit
            Me.ClientSize = New System.Drawing.Size(240, 268)
            Me.Controls.Add(Me.dataGridCars)
            Me.Controls.Add(Me.buttonMerge)
            Me.Controls.Add(Me.buttonAddCar)
            Me.Controls.Add(Me.textBoxLocation)
            Me.Controls.Add(Me.label2)
            Me.Controls.Add(Me.textBoxReg)
            Me.Controls.Add(Me.label1)
            Me.Menu = Me.mainMenu1
            Me.MinimizeBox = False
            Me.Name = "FormMR"
            Me.Text = "Traffic"
            AddHandler Me.Closing, AddressOf Me.FormMR_Closing
            AddHandler Me.Load, AddressOf Me.FormMR_Load
            Me.ResumeLayout(False)

        End Sub
#End Region

        '' <summary>
        '' The main entry point for the application.
        '' </summary>
        Shared Sub Main()

            Application.Run(New FormMR())
        End Sub

        Private Sub FormMR_Load(ByVal sender As Object, ByVal e As System.EventArgs)

            '' Configure the DataAdapter for use in UI binding
            cnCars = New SqlCeConnection("Data Source=\My Documents\TrafficMR.sdf")
            daCars = New SqlCeDataAdapter("SELECT CarId, Reg, Location FROM Cars", cnCars)

            '' Configure the update comand
            Dim cb As New SqlCeCommandBuilder(daCars)

            Merge()
        End Sub

        Private Sub Merge()
            Const URL As String = "http://homelaptop/mergerep/sqlcesa30.dll"     '' URL to Agent
            Const InterNetUser As String = "homelaptop\danial"                  '' InternetUser
            Const InternetPassword As String = "danial"                       '' InternetPassword
            Const PublisherServer As String = "homelaptop"                        '' Publisher server
            Const PublisherDatabase As String = "Traffic"                       '' Publisher Database
            Const PublicationName As String = "TrafficMR"                       '' Publication name
            Const SubscriberName As String = "Testing"                          '' Subscriber name
            Const LocalDB As String = "Data Source=\My Documents\TrafficMR.sdf" ''Connection string to local database

            Using rep As New SqlCeReplication(URL, InterNetUser, InternetPassword, PublisherServer, PublisherDatabase, PublicationName, SubscriberName, LocalDB)
                Try
                    If Not System.IO.File.Exists("\My Documents\TrafficMR.sdf") Then

                        rep.AddSubscription(AddOption.CreateDatabase)
                    End If

                    rep.Synchronize()

                Catch ex As SqlCeException

                    DisplaySQLCEErrors(ex)

                End Try
            End Using

            SetupDataSetforUI()
        End Sub

        Private Sub SetupDataSetforUI()
            '' Set up the dataset which is the data source for the UI
            If dsCars Is Nothing Then

                dsCars = New DataSet()
            End If

            Try
                dsCars.Clear()
                daCars.Fill(dsCars, "Cars")
                dsCars.Tables("Cars").Columns("CarID").AutoIncrement = True

                ''Get current highest value in that column
                cnCars.Open()

                Dim MaxCarID As Integer = -1

                Using cmd As New SqlCeCommand("SELECT MAX(CarID) FROM Cars", cnCars)
                    Dim result As Object = cmd.ExecuteScalar()

                    If Not IsDBNull(result) Then
                        MaxCarID = Convert.ToInt32(result)
                    End If
                End Using

                cnCars.Close()

                '' Set the AutoIncrement seed accordingly
                Me.dsCars.Tables("Cars").Columns("CarID").AutoIncrementSeed = MaxCarID + 1

                carsBindingSource.DataSource = dsCars
                carsBindingSource.DataMember = "Cars"

            Catch ex As SqlCeException

                DisplaySQLCEErrors(ex)

            End Try
        End Sub

        Private Sub DisplaySQLCEErrors(ByVal ex As SqlCeException)
            For i As Integer = 0 To ex.Errors.Count - 1
                MessageBox.Show("Index #" + i.ToString() + vbNewLine + ex.Errors(i).Source + vbNewLine + "Error: " + ex.Errors(i).Message, "Error No. " + ex.Errors(i).NativeError.ToString())
            Next
        End Sub

        Private Sub buttonAddCar_Click(ByVal sender As Object, ByVal e As System.EventArgs)
            Me.dsCars.Tables("Cars").Rows.Add(New Object() {Nothing, Me.textBoxReg.Text, Me.textBoxLocation.Text})

            Try
                '' Call Update on the DataAdapter to write to database
                daCars.Update(dsCars, "Cars")

            Catch ex As SqlCeException

                DisplaySQLCEErrors(ex)
            End Try
        End Sub

        Private Sub buttonMerge_Click(ByVal sender As Object, ByVal e As System.EventArgs)
            Merge()
            MessageBox.Show("Merge complete")
        End Sub

        Private Sub FormMR_Closing(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs)
            cnCars.Close()
            cnCars.Dispose()
        End Sub
    End Class
End Namespace