Método BeginSynchronize

Inicia uma sincronização de dados assíncronos.

Lista de sobrecargas

	Nome	Descrição
	BeginSynchronize(AsyncCallback, Object)	Inicia uma operação de sincronização de dados assíncronos. Quando a sincronização é encerrada, os representantes de AsyncCallback são chamados. Durante a sincronização, nenhum relatório de status é executado.
	BeginSynchronize(AsyncCallback, OnStartTableUpload, OnStartTableDownload, OnSynchronization, Object)	Inicia uma operação de sincronização de dados assíncronos. Quando a sincronização é encerrada, os representantes de AsyncCallback são chamados. Durante a sincronização, os relatórios de status da sincronização são enviados para os representantes de SyncStatusReport.

Início

Comentários

Para obter informações sobre a sincronização de dados assíncronos no SQL Server Compact 3.5, consulte "Sincronização de dados assíncronos" nos Manuais Online do SQL Server Compact 3.5.

Exemplos

O exemplo a seguir mostra como configurar a replicação do SQL Server Compact 3.5 para executar a sincronização de dados assíncronos.

' Imports System;
' Imports System.Data;
' Imports System.IO;
' Imports System.Data.SqlServerCe;
' Imports System.Windows.Forms;

'/ <summary>
'/ Demonstrates the usage of asynchronous database synchronization
'/ </summary>
Public Class MyForm
    Inherits Form

    Private myUserInterfaceUpdateEvent As EventHandler
    Private tableName As String
    Private percentage As Integer
    Private eventStatus As SyncStatus
    Private repl As SqlCeReplication

    Friend Enum SyncStatus
        PercentComplete
        BeginUpload
        BeginDownload
        SyncComplete
    End Enum 'SyncStatus

    Public Sub New()
        ' InitializeComponent();
        Me.myUserInterfaceUpdateEvent = New EventHandler(AddressOf UserInterfaceUpdateEvent)

    End Sub 'New

    Private Sub UserInterfaceUpdateEvent(ByVal sender As Object, ByVal e As System.EventArgs)
        Select Case Me.eventStatus
            Case SyncStatus.BeginUpload
                'this.labelStatusValue.Text = "Began uploading table : " & tableName;

            Case SyncStatus.PercentComplete
                'this.labelStatusValue.Text = "Sync with SQL Server is " & percentage.ToString() & "% complete.";

            Case SyncStatus.BeginDownload
                'this.labelStatusValue.Text = "Began downloading table : " & tableName;

            Case SyncStatus.SyncComplete
                'this.labelStatusValue.Text = "Synchronization has completed successfully";
                'this.labelLastSyncValue.Text = GetLastSuccessfulSyncTime().ToString();
        End Select
    End Sub 'UserInterfaceUpdateEvent

    Public Sub SyncCompletedCallback(ByVal ar As IAsyncResult)
        Try
            Dim repl As SqlCeReplication = CType(ar.AsyncState, SqlCeReplication)

            repl.EndSynchronize(ar)
            repl.SaveProperties()

            Me.eventStatus = SyncStatus.SyncComplete
        Catch e As SqlCeException
            MessageBox.Show(e.Message)
        Finally
            ' NOTE: If you'd like to set Control properties from within this 
            ' method, you need to use Control.Invoke method in order to marshal
            ' the call to the UI thread; otherwise you might deadlock your 
            ' application; See Control.Invoke documentation for more information
            '
            Me.Invoke(Me.myUserInterfaceUpdateEvent)
        End Try

    End Sub 'SyncCompletedCallback

    Public Sub OnStartTableUploadCallback(ByVal ar As IAsyncResult, ByVal tableName As String)
        Me.tableName = tableName
        Me.eventStatus = SyncStatus.BeginUpload

        ' NOTE: If you'd like to set Control properties from within this 
        ' method, you need to use Control.Invoke method in order to marshal
        ' the call to the UI thread; otherwise you might deadlock your 
        ' application; See Control.Invoke documentation for more information
        '
        Me.Invoke(Me.myUserInterfaceUpdateEvent)

    End Sub 'OnStartTableUploadCallback

    Public Sub OnSynchronizationCallback(ByVal ar As IAsyncResult, ByVal percentComplete As Integer)
        Me.percentage = percentComplete
        Me.eventStatus = SyncStatus.PercentComplete

        ' NOTE: If you'd like to set Control properties from within this 
        ' method, you need to use Control.Invoke method in order to marshal
        ' the call to the UI thread; otherwise you might deadlock your 
        ' application; See Control.Invoke documentation for more information
        '
        Me.Invoke(Me.myUserInterfaceUpdateEvent)

    End Sub 'OnSynchronizationCallback

    Public Sub OnStartTableDownloadCallback(ByVal ar As IAsyncResult, ByVal tableName As String)
        Me.tableName = tableName
        Me.eventStatus = SyncStatus.BeginDownload

        ' NOTE: If you'd like to set Control properties from within this 
        ' method, you need to use Control.Invoke method in order to marshal
        ' the call to the UI thread; otherwise you might deadlock your 
        ' application; See Control.Invoke documentation for more information
        '
        Me.Invoke(Me.myUserInterfaceUpdateEvent)

    End Sub 'OnStartTableDownloadCallback

    Private Sub ButtonSynchronize_Click(ByVal sender As Object, ByVal e As System.EventArgs)
        Try
            Me.repl = New SqlCeReplication()
            repl.SubscriberConnectionString = "Data Source=Test.sdf"

            '
            'NOTE: when possible, prompt users to enter security 
            'credentials at runtime. If you store credentials in a file, 
            'you must secure the file to prevent unauthorized access.
            '
            If False = File.Exists("Test.sdf") Then
                repl.AddSubscription(AddOption.CreateDatabase)
                repl.PublisherSecurityMode = SecurityType.DBAuthentication
                repl.Publisher = "MyPublisher"
                repl.PublisherLogin = "PublisherLogin"
                repl.PublisherPassword = "<enterStrongPassword>"
                repl.PublisherDatabase = "AdventureWorksDW"
                repl.Publication = "AdventureWorksDW"
                repl.InternetUrl = "https://www.adventure-works.com/sqlmobile/sqlcesa35.dll"
                repl.InternetLogin = "InternetLogin"
                repl.InternetPassword = "<enterStrongPassword>"
                repl.Subscriber = "MySubscriber"
            Else
                repl.LoadProperties()
            End If

            Dim ar As IAsyncResult = repl.BeginSynchronize( _
                New AsyncCallback(AddressOf Me.SyncCompletedCallback), _
                New OnStartTableUpload(AddressOf Me.OnStartTableUploadCallback), _
                New OnStartTableDownload(AddressOf Me.OnStartTableDownloadCallback), _
                New OnSynchronization(AddressOf Me.OnSynchronizationCallback), repl)

        Catch ex As SqlCeException
            MessageBox.Show(ex.Message)
        End Try

    End Sub 'ButtonSynchronize_Click

    Public Function GetLastSuccessfulSyncTime() As DateTime
        Dim utcDateTime As DateTime
        Dim localDateTime As DateTime

        Dim conn As SqlCeConnection = Nothing
        Dim cmd As SqlCeCommand = Nothing

        Try
            conn = New SqlCeConnection("Data Source = Test.sdf")
            conn.Open()

            cmd = conn.CreateCommand()
            cmd.CommandText = "SELECT LastSuccessfulSync FROM __sysMergeSubscriptions " & _
                "WHERE Publication=@publication"

            cmd.Parameters.Add("@publication", SqlDbType.NVarChar, 4000)
            cmd.Parameters("@publication").Value = "AdventureWorksDW"

            utcDateTime = CType(cmd.ExecuteScalar(), DateTime)
            localDateTime = utcDateTime.ToLocalTime()

            Return localDateTime
        Finally
            conn.Close()
        End Try

    End Function 'GetLastSuccessfulSyncTime
End Class 'MyForm

// using System;
// using System.Data;
// using System.IO;
// using System.Data.SqlServerCe;
// using System.Windows.Forms;

/// <summary>
/// Demonstrates the usage of asynchronous database synchronization
/// </summary>
public class MyForm : Form
{
    private string tableName;
    private int percentage;
    private SyncStatus eventStatus;
    private SqlCeReplication repl;
    private EventHandler myUserInterfaceUpdateEvent;

    internal enum SyncStatus
    {
        PercentComplete,
        BeginUpload,
        BeginDownload,
        SyncComplete
    }

    public MyForm()
    {
        // InitializeComponent();
        this.myUserInterfaceUpdateEvent = new EventHandler(MyUserInterfaceUpdateEvent);
    }

    private void MyUserInterfaceUpdateEvent(object sender, System.EventArgs e)
    {
        switch (this.eventStatus)
        {
            case SyncStatus.BeginUpload:
                //this.labelStatusValue.Text = "Began uploading table : " + tableName;
                break;

            case SyncStatus.PercentComplete:
                //this.labelStatusValue.Text = "Sync with SQL Server is " + percentage.ToString() + "% complete.";
                break;

            case SyncStatus.BeginDownload:
                //this.labelStatusValue.Text = "Began downloading table : " + tableName;
                break;

            case SyncStatus.SyncComplete:
                //this.labelStatusValue.Text = "Synchronization has completed successfully";
                //this.labelLastSyncValue.Text = GetLastSuccessfulSyncTime().ToString();
                break;
        }
    }

    public void SyncCompletedCallback(IAsyncResult ar)
    {
        try
        {
            SqlCeReplication repl = (SqlCeReplication)ar.AsyncState;

            repl.EndSynchronize(ar);
            repl.SaveProperties();

            this.eventStatus = SyncStatus.SyncComplete;
        }
        catch (SqlCeException e)
        {
            MessageBox.Show(e.Message);
        }
        finally
        {
            // NOTE: If you'd like to set Control properties from within this 
            // method, you need to use Control.Invoke method in order to marshal
            // the call to the UI thread; otherwise you might deadlock your 
            // application; See Control.Invoke documentation for more information
            //
            this.Invoke(this.myUserInterfaceUpdateEvent);
        }
    }

    public void OnStartTableUploadCallback(IAsyncResult ar, string tableName)
    {
        this.tableName = tableName;
        this.eventStatus = SyncStatus.BeginUpload;

        // NOTE: If you'd like to set Control properties from within this 
        // method, you need to use Control.Invoke method in order to marshal
        // the call to the UI thread; otherwise you might deadlock your 
        // application; See Control.Invoke documentation for more information
        //
        this.Invoke(this.myUserInterfaceUpdateEvent);
    }

    public void OnSynchronizationCallback(IAsyncResult ar, int percentComplete)
    {
        this.percentage = percentComplete;
        this.eventStatus = SyncStatus.PercentComplete;

        // NOTE: If you'd like to set Control properties from within this 
        // method, you need to use Control.Invoke method in order to marshal
        // the call to the UI thread; otherwise you might deadlock your 
        // application; See Control.Invoke documentation for more information
        //
        this.Invoke(this.myUserInterfaceUpdateEvent);
    }

    public void OnStartTableDownloadCallback(IAsyncResult ar, string tableName)
    {
        this.tableName = tableName;
        this.eventStatus = SyncStatus.BeginDownload;

        // NOTE: If you'd like to set Control properties from within this 
        // method, you need to use Control.Invoke method in order to marshal
        // the call to the UI thread; otherwise you might deadlock your 
        // application; See Control.Invoke documentation for more information
        //
        this.Invoke(this.myUserInterfaceUpdateEvent);
    }

    private void ButtonSynchronize_Click(object sender, System.EventArgs e)
    {
        try
        {
            this.repl = new SqlCeReplication();
            repl.SubscriberConnectionString = "Data Source=Test.sdf";

            if (false == File.Exists("Test.sdf"))
            {
                //NOTE: when possible, prompt users to enter security 
                //credentials at runtime. If you store credentials in a file, 
                //you must secure the file to prevent unauthorized access.
                //
                repl.AddSubscription(AddOption.CreateDatabase);
                repl.PublisherSecurityMode = SecurityType.DBAuthentication;
                repl.Publisher = "MyPublisher";
                repl.PublisherLogin = "PublisherLogin";
                repl.PublisherPassword = "<enterStrongPassword>";
                repl.PublisherDatabase = "AdventureWorksDW";
                repl.Publication = "AdventureWorksDW";
                repl.InternetUrl = "https://www.adventure-works.com/sqlmobile/sqlcesa35.dll";
                repl.InternetLogin = "MyInternetLogin";
                repl.InternetPassword = "<enterStrongPassword>";
                repl.Subscriber = "MySubscriber";
            }
            else
            {
                repl.LoadProperties();
            }

            IAsyncResult ar = repl.BeginSynchronize(
                new AsyncCallback(this.SyncCompletedCallback),
                new OnStartTableUpload(this.OnStartTableUploadCallback),
                new OnStartTableDownload(this.OnStartTableDownloadCallback),
                new OnSynchronization(this.OnSynchronizationCallback), 
                repl);
        }
        catch (SqlCeException ex)
        {
            MessageBox.Show(ex.Message);
        }
    }

    public DateTime GetLastSuccessfulSyncTime()
    {
        DateTime utcDateTime;
        DateTime localDateTime;
        SqlCeConnection conn = null;
        SqlCeCommand cmd = null;

        try
        {
            conn = new SqlCeConnection("Data Source = Test.sdf");
            conn.Open();

            cmd = conn.CreateCommand();
            cmd.CommandText = "SELECT LastSuccessfulSync FROM __sysMergeSubscriptions " +
                "WHERE Publication=@publication";

            cmd.Parameters.Add("@publication", SqlDbType.NVarChar, 4000);
            cmd.Parameters["@publication"].Value = "AdventureWorksDW";

            utcDateTime = (DateTime)cmd.ExecuteScalar();
            localDateTime = utcDateTime.ToLocalTime();

            return localDateTime;
        }
        finally
        {
            conn.Close();
        }
    }
}

Consulte também

Referência

SqlCeReplication Classe

Membros SqlCeReplication

Namespace System.Data.SqlServerCe