BeginSynchronize Method
Starts an asynchronous data synchronization.
Overload List
| Name | Description | |
|---|---|---|
.gif "Public method") |
BeginSynchronize(AsyncCallback, Object) | Starts an asynchronous data synchronization operation. When synchronization ends, the AsyncCallback delegates are called. During synchronization, no status reporting is performed. |
|
BeginSynchronize(AsyncCallback, OnStartTableUpload, OnStartTableDownload, OnSynchronization, Object) | Starts an asynchronous data synchronization operation. When the synchronization ends, the AsyncCallback delegates are called. During the synchronization, synchronization status reports are sent to the SyncStatusReport delegates. |
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Remarks
For information about asynchronous data synchronization in , see "Asynchronous Data Synchronization" in the Books Online.
Examples
The following example shows how to set up replication to perform asynchronous data synchronization.
' 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();
}
}
}