启动异步数据同步操作。同步结束时，将调用 AsyncCallback 委托。在同步期间，会将同步状态报告发送给 SyncStatusReport 委托。
命名空间： System.Data.SqlServerCe
程序集： System.Data.SqlServerCe（在 System.Data.SqlServerCe.dll 中）
语法
声明
Public Function BeginSynchronize ( _
onSyncCompletion As AsyncCallback, _
onStartTableUpload As OnStartTableUpload, _
onStartTableDownload As OnStartTableDownload, _
onSynchronization As OnSynchronization, _
state As Object _
) As IAsyncResult
用法
Dim instance As SqlCeReplication
Dim onSyncCompletion As AsyncCallback
Dim onStartTableUpload As OnStartTableUpload
Dim onStartTableDownload As OnStartTableDownload
Dim onSynchronization As OnSynchronization
Dim state As Object
Dim returnValue As IAsyncResult
returnValue = instance.BeginSynchronize(onSyncCompletion, _
onStartTableUpload, onStartTableDownload, _
onSynchronization, state)
public IAsyncResult BeginSynchronize(
AsyncCallback onSyncCompletion,
OnStartTableUpload onStartTableUpload,
OnStartTableDownload onStartTableDownload,
OnSynchronization onSynchronization,
Object state
)
public:
IAsyncResult^ BeginSynchronize(
AsyncCallback^ onSyncCompletion,
OnStartTableUpload^ onStartTableUpload,
OnStartTableDownload^ onStartTableDownload,
OnSynchronization^ onSynchronization,
Object^ state
)
member BeginSynchronize :
onSyncCompletion:AsyncCallback *
onStartTableUpload:OnStartTableUpload *
onStartTableDownload:OnStartTableDownload *
onSynchronization:OnSynchronization *
state:Object -> IAsyncResult
public function BeginSynchronize(
onSyncCompletion : AsyncCallback,
onStartTableUpload : OnStartTableUpload,
onStartTableDownload : OnStartTableDownload,
onSynchronization : OnSynchronization,
state : Object
) : IAsyncResult
参数
- onSyncCompletion
类型：System. . :: . .AsyncCallback
由调用方实现的、在同步结束时调用的 AsyncCallback 委托。
- onStartTableUpload
类型：System.Data.SqlServerCe. . :: . .OnStartTableUpload
用户为开始将表更改上载到服务器时激发的事件定义的委托。
- onStartTableDownload
类型：System.Data.SqlServerCe. . :: . .OnStartTableDownload
用户为开始从服务器下载表更改时激发的事件定义的委托。
- onSynchronization
类型：System.Data.SqlServerCe. . :: . .OnSynchronization
一种用户定义的委托，它使用协调器工作期间报告的正在发生的同步事件。
- state
类型：System. . :: . .Object
AsyncState 属性返回的用户定义的对象。
返回值
类型：System. . :: . .IAsyncResult
已通过调用此函数启动的异步操作使用的 IAsyncResult 接口。您可以使用此接口测试同步是否已完成，也可以一直等到同步结束。
注释
有关 SQL Server Compact 3.5 中的异步数据同步的信息，请参阅 SQL Server Compact 3.5 联机丛书中的“异步数据同步”。
示例
下面的示例演示如何设置 SQL Server Compact 3.5 复制以执行异步数据同步。
' 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();
}
}
}