如何处理事件和对业务逻辑进行编程
本主题演示如何在 Sync Services for ADO.NET 中处理事件和业务逻辑。本主题中的示例着重介绍以下 Sync Services 类型和事件：
SyncAgent StateChanged 事件和 SessionStateChangedEventArgs
SyncAgent SessionProgress 事件和 SessionProgressEventArgs
DbServerSyncProvider ApplyingChanges 事件和 SqlCeClientSyncProvider ApplyingChanges 事件以及 ApplyingChangesEventArgs
SqlCeClientSyncProvider SchemaCreated 事件和 SchemaCreatedEventArgs
DbServerSyncProvider ChangesSelected 事件和 SqlCeClientSyncProvider ChangesSelected 事件以及 ChangesSelectedEventArgs
DbServerSyncProvider ChangesApplied 事件和 SqlCeClientSyncProvider ChangesApplied 事件以及 ChangesAppliedEventArgs
DbServerSyncProvider ApplyChangeFailed 事件和 SqlCeClientSyncProvider ApplyChangeFailed 事件以及 ApplyChangeFailedEventArgs
有关如何运行示例代码的信息，请参见对常见客户端与服务器同步任务进行编程中的“帮助主题中的示例应用程序”。
了解 Sync Services 事件
Sync Services 提供了许多事件，在同步期间这些事件会公开您可以使用的数据和元数据。例如，SchemaCreatedEventArgs 对象提供对在客户端数据库中创建的每个表的 SyncSchema 对象的访问，以及可用来创建架构的连接和事务。这样，您可以在与客户端同步提供程序相同的事务之内，通过 API 来变更架构。
引发事件的时间与其使用相对应，正如您在以下示例中所看到的：
在创建完每个表之后会引发 SchemaCreated 事件。如果必须在创建另一个表之前变更表的架构，这一点十分有用。
在为每个同步组应用变更之前会引发 DbServerSyncProvider ApplyingChanges 事件和 SqlCeClientSyncProvider ApplyingChanges 事件。这样，您便可以在应用变更之前，查看一组相关表的元数据和变更集。
在每次未能应用某行后会引发 DbServerSyncProvider ApplyChangeFailed 事件和 SqlCeClientSyncProvider ApplyChangeFailed 事件。这可能是由于出现了错误或数据冲突。通过这些事件，在继续处理过程之前，您可以对每个错误做出响应。这样可以降低在重试失败的变更时尝试的次数。
示例
本主题中的示例代码演示如何按照以下方法响应 Sync Services 事件：在屏幕上显示同步进度，为成功应用的变更和应用失败的变更记录与事件相关的数据，以及在同步期间变更数据以强制执行业务逻辑。我们没有将此示例分解为多个代码示例，使用一个完整的示例有助于运行示例代码以及查看 EventLogger 和 SampleStatsAndProgress 类为每个事件显示和记录的数据。但是，在运行示例代码之前，建议您首先查看以下代码示例。
在同步期间执行业务逻辑
本示例演示在同步期间对数据的控制。它演示了如何通过处理服务器端的 ApplyingChanges 事件在变更集应用于服务器之前访问该变更集。此外，示例还演示了如何引入客户端事件的逻辑。在本例中更新了一个列的数据。但是，在服务器或客户端上，在提交变更之前也可以轻松地执行一次库存检查，或者执行应用程序需要的任何其他业务逻辑。有关在发生数据冲突时如何执行此操作的示例，请参见如何处理数据冲突和错误。
private void SampleServerSyncProvider_ApplyingChanges(object sender, ApplyingChangesEventArgs e)
{
DataTable customerDataTable = e.Changes.Tables["Customer"];
for (int i = 0; i < customerDataTable.Rows.Count; i++)
{
if (customerDataTable.Rows[i].RowState == DataRowState.Added
&& customerDataTable.Rows[i]["CustomerType"] == "Wholesale")
{
customerDataTable.Rows[i]["CustomerType"] = "Wholesale (from mobile sales)";
}
}
}
Private Sub SampleServerSyncProvider_ApplyingChanges(ByVal sender As Object, ByVal e As ApplyingChangesEventArgs)
Dim customerDataTable As DataTable = e.Changes.Tables("Customer")
Dim i As Integer
For i = 1 To customerDataTable.Rows.Count - 1
If customerDataTable.Rows(i).RowState = DataRowState.Added _
AndAlso customerDataTable.Rows(i)("CustomerType") = "Wholesale" Then
customerDataTable.Rows(i)("CustomerType") = "Wholesale (from mobile sales)"
End If
Next i
End Sub
完整的代码示例
下面的完整代码示例需要 Utility 类，可通过用于 Sync Services 帮助主题的 Utility 类获得该类。
using System;
using System.Collections;
using System.IO;
using System.Text;
using System.Data;
using System.Data.SqlClient;
using System.Data.SqlServerCe;
using Microsoft.Synchronization;
using Microsoft.Synchronization.Data;
using Microsoft.Synchronization.Data.Server;
using Microsoft.Synchronization.Data.SqlServerCe;
namespace Microsoft.Samples.Synchronization
{
class Program
{
static void Main(string[] args)
{
//The Utility class handles all functionality that is not
//directly related to synchronization, such as holding connection
//string information, and making changes to the server and client databases.
Utility util = new Utility();
//The SampleStatsAndProgress class handles information from the
//SyncStatistics object that the Synchronize method returns and
//from SyncAgent events.
SampleStatsAndProgress sampleStats = new SampleStatsAndProgress();
//Request a password for the client database, and delete
//and re-create the database. The client synchronization
//provider also enables you to create the client database
//if it does not exist.
util.SetClientPassword();
util.RecreateClientDatabase();
//Initial synchronization. Instantiate the SyncAgent
//and call Synchronize.
SampleSyncAgent sampleSyncAgent = new SampleSyncAgent();
SyncStatistics syncStatistics = sampleSyncAgent.Synchronize();
sampleStats.DisplayStats(syncStatistics, "initial");
//Make changes on the server and client.
util.MakeDataChangesOnServer("Customer");
util.MakeDataChangesOnClient("Customer");
//Subsequent synchronization.
syncStatistics = sampleSyncAgent.Synchronize();
sampleStats.DisplayStats(syncStatistics, "subsequent");
//Make a change at the client that fails when it is
//applied at the server.
util.MakeFailingChangesOnClient();
//Subsequent synchronization.
syncStatistics = sampleSyncAgent.Synchronize();
sampleStats.DisplayStats(syncStatistics, "subsequent");
//Return server data back to its original state.
util.CleanUpServer();
//Exit.
Console.Write("\nPress Enter to close the window.");
Console.ReadLine();
}
}
//Create a class that is derived from
//Microsoft.Synchronization.SyncAgent.
public class SampleSyncAgent : SyncAgent
{
public SampleSyncAgent()
{
//Instantiate a client synchronization provider and specify it
//as the local provider for this synchronization agent.
this.LocalProvider = new SampleClientSyncProvider();
//Instantiate a server synchronization provider and specify it
//as the remote provider for this synchronization agent.
this.RemoteProvider = new SampleServerSyncProvider();
//Create two SyncGroups so that changes to OrderHeader
//and OrderDetail are made in one transaction. Depending on
//application requirements, you might include Customer
//in the same group.
SyncGroup customerSyncGroup = new SyncGroup("Customer");
SyncGroup orderSyncGroup = new SyncGroup("Order");
//Add each table: specify a synchronization direction of
//Bidirectional.
SyncTable customerSyncTable = new SyncTable("Customer");
customerSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable;
customerSyncTable.SyncDirection = SyncDirection.Bidirectional;
customerSyncTable.SyncGroup = customerSyncGroup;
this.Configuration.SyncTables.Add(customerSyncTable);
SyncTable orderHeaderSyncTable = new SyncTable("OrderHeader");
orderHeaderSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable;
orderHeaderSyncTable.SyncDirection = SyncDirection.Bidirectional;
orderHeaderSyncTable.SyncGroup = orderSyncGroup;
this.Configuration.SyncTables.Add(orderHeaderSyncTable);
SyncTable orderDetailSyncTable = new SyncTable("OrderDetail");
orderDetailSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable;
orderDetailSyncTable.SyncDirection = SyncDirection.Bidirectional;
orderDetailSyncTable.SyncGroup = orderSyncGroup;
this.Configuration.SyncTables.Add(orderDetailSyncTable);
//Handle the StateChanged and SessionProgress events, and
//display information to the console.
SampleStatsAndProgress sampleStats = new SampleStatsAndProgress();
this.StateChanged += new EventHandler<SessionStateChangedEventArgs>(sampleStats.DisplaySessionProgress);
this.SessionProgress += new EventHandler<SessionProgressEventArgs>(sampleStats.DisplaySessionProgress);
}
}
//Create a class that is derived from
//Microsoft.Synchronization.Server.DbServerSyncProvider.
public class SampleServerSyncProvider : DbServerSyncProvider
{
public SampleServerSyncProvider()
{
//Create a connection to the sample server database.
Utility util = new Utility();
SqlConnection serverConn = new SqlConnection(util.ServerConnString);
this.Connection = serverConn;
//Create a command to retrieve a new anchor value from
//the server. In this case, we use a timestamp value
//that is retrieved and stored in the client database.
//During each synchronization, the new anchor value and
//the last anchor value from the previous synchronization
//are used: the set of changes between these upper and
//lower bounds is synchronized.
//
//SyncSession.SyncNewReceivedAnchor is a string constant;
//you could also use @sync_new_received_anchor directly in
//your queries.
SqlCommand selectNewAnchorCommand = new SqlCommand();
string newAnchorVariable = "@" + SyncSession.SyncNewReceivedAnchor;
selectNewAnchorCommand.CommandText = "SELECT " + newAnchorVariable + " = min_active_rowversion() - 1";
selectNewAnchorCommand.Parameters.Add(newAnchorVariable, SqlDbType.Timestamp);
selectNewAnchorCommand.Parameters[newAnchorVariable].Direction = ParameterDirection.Output;
selectNewAnchorCommand.Connection = serverConn;
this.SelectNewAnchorCommand = selectNewAnchorCommand;
//Create SyncAdapters for each table by using the SqlSyncAdapterBuilder:
// * Specify the base table and tombstone table names.
// * Specify the columns that are used to track when
// and where changes are made.
// * Specify bidirectional synchronization.
// * Call ToSyncAdapter to create the SyncAdapter.
// * Specify a name for the SyncAdapter that matches the
// the name specified for the corresponding SyncTable.
// Do not include the schema names (Sales in this case).
//Customer table
SqlSyncAdapterBuilder customerBuilder = new SqlSyncAdapterBuilder(serverConn);
customerBuilder.TableName = "Sales.Customer";
customerBuilder.TombstoneTableName = customerBuilder.TableName + "_Tombstone";
customerBuilder.SyncDirection = SyncDirection.Bidirectional;
customerBuilder.CreationTrackingColumn = "InsertTimestamp";
customerBuilder.UpdateTrackingColumn = "UpdateTimestamp";
customerBuilder.DeletionTrackingColumn = "DeleteTimestamp";
customerBuilder.CreationOriginatorIdColumn = "InsertId";
customerBuilder.UpdateOriginatorIdColumn = "UpdateId";
customerBuilder.DeletionOriginatorIdColumn = "DeleteId";
SyncAdapter customerSyncAdapter = customerBuilder.ToSyncAdapter();
customerSyncAdapter.TableName = "Customer";
this.SyncAdapters.Add(customerSyncAdapter);
//OrderHeader table.
SqlSyncAdapterBuilder orderHeaderBuilder = new SqlSyncAdapterBuilder(serverConn);
orderHeaderBuilder.TableName = "Sales.OrderHeader";
orderHeaderBuilder.TombstoneTableName = orderHeaderBuilder.TableName + "_Tombstone";
orderHeaderBuilder.SyncDirection = SyncDirection.Bidirectional;
orderHeaderBuilder.CreationTrackingColumn = "InsertTimestamp";
orderHeaderBuilder.UpdateTrackingColumn = "UpdateTimestamp";
orderHeaderBuilder.DeletionTrackingColumn = "DeleteTimestamp";
orderHeaderBuilder.CreationOriginatorIdColumn = "InsertId";
orderHeaderBuilder.UpdateOriginatorIdColumn = "UpdateId";
orderHeaderBuilder.DeletionOriginatorIdColumn = "DeleteId";
SyncAdapter orderHeaderSyncAdapter = orderHeaderBuilder.ToSyncAdapter();
orderHeaderSyncAdapter.TableName = "OrderHeader";
this.SyncAdapters.Add(orderHeaderSyncAdapter);
//OrderDetail table.
SqlSyncAdapterBuilder orderDetailBuilder = new SqlSyncAdapterBuilder(serverConn);
orderDetailBuilder.TableName = "Sales.OrderDetail";
orderDetailBuilder.TombstoneTableName = orderDetailBuilder.TableName + "_Tombstone";
orderDetailBuilder.SyncDirection = SyncDirection.Bidirectional;
orderDetailBuilder.CreationTrackingColumn = "InsertTimestamp";
orderDetailBuilder.UpdateTrackingColumn = "UpdateTimestamp";
orderDetailBuilder.DeletionTrackingColumn = "DeleteTimestamp";
orderDetailBuilder.CreationOriginatorIdColumn = "InsertId";
orderDetailBuilder.UpdateOriginatorIdColumn = "UpdateId";
orderDetailBuilder.DeletionOriginatorIdColumn = "DeleteId";
SyncAdapter orderDetailSyncAdapter = orderDetailBuilder.ToSyncAdapter();
orderDetailSyncAdapter.TableName = "OrderDetail";
this.SyncAdapters.Add(orderDetailSyncAdapter);
//Log information for the following events.
this.ChangesSelected += new EventHandler<ChangesSelectedEventArgs>(EventLogger.LogEvents);
this.ChangesApplied += new EventHandler<ChangesAppliedEventArgs>(EventLogger.LogEvents);
this.ApplyChangeFailed += new EventHandler<ApplyChangeFailedEventArgs>(EventLogger.LogEvents);
//Handle the ApplyingChanges event so that we can
//make changes to the dataset.
this.ApplyingChanges += new EventHandler<ApplyingChangesEventArgs>(SampleServerSyncProvider_ApplyingChanges);
}
//Look for inserted rows in the dataset that have a CustomerType
//of Wholesale and update these rows. With access to the dataset,
//you can write any business logic that your application requires.
private void SampleServerSyncProvider_ApplyingChanges(object sender, ApplyingChangesEventArgs e)
{
DataTable customerDataTable = e.Changes.Tables["Customer"];
for (int i = 0; i < customerDataTable.Rows.Count; i++)
{
if (customerDataTable.Rows[i].RowState == DataRowState.Added
&& customerDataTable.Rows[i]["CustomerType"] == "Wholesale")
{
customerDataTable.Rows[i]["CustomerType"] = "Wholesale (from mobile sales)";
}
}
}
}
//Create a class that is derived from
//Microsoft.Synchronization.Data.SqlServerCe.SqlCeClientSyncProvider.
//You can just instantiate the provider directly and associate it
//with the SyncAgent, but here we use this class to handle client
//provider events.
public class SampleClientSyncProvider : SqlCeClientSyncProvider
{
public SampleClientSyncProvider()
{
//Specify a connection string for the sample client database.
Utility util = new Utility();
this.ConnectionString = util.ClientConnString;
//Log information for the following events.
this.SchemaCreated += new EventHandler<SchemaCreatedEventArgs>(EventLogger.LogEvents);
this.ChangesSelected += new EventHandler<ChangesSelectedEventArgs>(EventLogger.LogEvents);
this.ChangesApplied += new EventHandler<ChangesAppliedEventArgs>(EventLogger.LogEvents);
this.ApplyChangeFailed += new EventHandler<ApplyChangeFailedEventArgs>(EventLogger.LogEvents);
//Use the following events to fix up schema on the client.
//We use the CreatingSchema event to change the schema
//by using the API. We use the SchemaCreated event
//to change the schema by using SQL.
//Note that both schema events fire for the Customer table,
//even though we already created the table. This allows us
//to work with the table at this point if we have to.
this.CreatingSchema += new EventHandler<CreatingSchemaEventArgs>(SampleClientSyncProvider_CreatingSchema);
this.SchemaCreated += new EventHandler<SchemaCreatedEventArgs>(SampleClientSyncProvider_SchemaCreated);
}
private void SampleClientSyncProvider_CreatingSchema(object sender, CreatingSchemaEventArgs e)
{
string tableName = e.Table.TableName;
if (tableName == "Customer")
{
//Set the RowGuid property because it is not copied
//to the client by default. This is also a good time
//to specify literal defaults with .Columns[ColName].DefaultValue,
//but we will specify defaults like NEWID() by calling
//ALTER TABLE after the table is created.
e.Schema.Tables["Customer"].Columns["CustomerId"].RowGuid = true;
}
if (tableName == "OrderHeader")
{
e.Schema.Tables["OrderHeader"].Columns["OrderId"].RowGuid = true;
}
}
private void SampleClientSyncProvider_SchemaCreated(object sender, SchemaCreatedEventArgs e)
{
string tableName = e.Table.TableName;
Utility util = new Utility();
//Call ALTER TABLE on the client. This must be done
//over the same connection and within the same
//transaction that Synchronization Services uses
//to create the schema on the client.
if (tableName == "Customer")
{
util.MakeSchemaChangesOnClient(e.Connection, e.Transaction, "Customer");
}
if (tableName == "OrderHeader")
{
util.MakeSchemaChangesOnClient(e.Connection, e.Transaction, "OrderHeader");
}
if (tableName == "OrderDetail")
{
util.MakeSchemaChangesOnClient(e.Connection, e.Transaction, "OrderDetail");
}
}
}
//Handle SyncAgent events and the statistics that are returned by the SyncAgent.
public class SampleStatsAndProgress
{
public void DisplayStats(SyncStatistics syncStatistics, string syncType)
{
Console.WriteLine(String.Empty);
if (syncType == "initial")
{
Console.WriteLine("****** Initial Synchronization Stats ******");
}
else if (syncType == "subsequent")
{
Console.WriteLine("***** Subsequent Synchronization Stats ****");
}
Console.WriteLine("Start Time: " + syncStatistics.SyncStartTime);
Console.WriteLine("Upload Changes Applied: " + syncStatistics.UploadChangesApplied);
Console.WriteLine("Upload Changes Failed: " + syncStatistics.UploadChangesFailed);
Console.WriteLine("Total Changes Uploaded: " + syncStatistics.TotalChangesUploaded);
Console.WriteLine("Download Changes Applied: " + syncStatistics.DownloadChangesApplied);
Console.WriteLine("Download Changes Failed: " + syncStatistics.DownloadChangesFailed);
Console.WriteLine("Total Changes Downloaded: " + syncStatistics.TotalChangesDownloaded);
Console.WriteLine("Complete Time: " + syncStatistics.SyncCompleteTime);
Console.WriteLine(String.Empty);
}
public void DisplaySessionProgress(object sender, EventArgs e)
{
StringBuilder outputText = new StringBuilder();
if (e is SessionStateChangedEventArgs)
{
SessionStateChangedEventArgs args = (SessionStateChangedEventArgs)e;
if (args.SessionState == SyncSessionState.Synchronizing)
{
outputText.AppendLine(String.Empty);
outputText.Append("** SyncAgent is synchronizing");
}
else
{
outputText.Append("** SyncAgent is ready to synchronize");
}
}
else if (e is SessionProgressEventArgs)
{
SessionProgressEventArgs args = (SessionProgressEventArgs)e;
outputText.Append("Percent complete: " + args.PercentCompleted + " (" + args.SyncStage + ")");
}
else
{
outputText.AppendLine("Unknown event occurred");
}
Console.WriteLine(outputText.ToString());
}
}
public class EventLogger
{
//Create client and server log files, and write to them
//based on data from several EventArgs classes.
public static void LogEvents(object sender, EventArgs e)
{
string logFile = String.Empty;
string site = String.Empty;
if (sender is SampleServerSyncProvider)
{
logFile = "ServerLogFile.txt";
site = "server";
}
else if (sender is SampleClientSyncProvider)
{
logFile = "ClientLogFile.txt";
site = "client";
}
StreamWriter streamWriter = File.AppendText(logFile);
StringBuilder outputText = new StringBuilder();
if (e is ChangesSelectedEventArgs)
{
ChangesSelectedEventArgs args = (ChangesSelectedEventArgs)e;
outputText.AppendLine("Client ID: " + args.Session.ClientId);
outputText.AppendLine("Changes selected from " + site + " for group " + args.GroupMetadata.GroupName);
outputText.AppendLine("Inserts selected from " + site + " for group: " + args.Context.GroupProgress.TotalInserts.ToString());
outputText.AppendLine("Updates selected from " + site + " for group: " + args.Context.GroupProgress.TotalUpdates.ToString());
outputText.AppendLine("Deletes selected from " + site + " for group: " + args.Context.GroupProgress.TotalDeletes.ToString());
}
else if (e is ChangesAppliedEventArgs)
{
ChangesAppliedEventArgs args = (ChangesAppliedEventArgs)e;
outputText.AppendLine("Client ID: " + args.Session.ClientId);
outputText.AppendLine("Changes applied to " + site + " for group " + args.GroupMetadata.GroupName);
outputText.AppendLine("Inserts applied to " + site + " for group: " + args.Context.GroupProgress.TotalInserts.ToString());
outputText.AppendLine("Updates applied to " + site + " for group: " + args.Context.GroupProgress.TotalUpdates.ToString());
outputText.AppendLine("Deletes applied to " + site + " for group: " + args.Context.GroupProgress.TotalDeletes.ToString());
}
else if (e is SchemaCreatedEventArgs)
{
SchemaCreatedEventArgs args = (SchemaCreatedEventArgs)e;
outputText.AppendLine("Schema creation for group: " + args.Table.SyncGroup.GroupName);
outputText.AppendLine("Table: " + args.Table.TableName);
outputText.AppendLine("Direction : " + args.Table.SyncDirection);
outputText.AppendLine("Creation Option: " + args.Table.CreationOption);
}
else if (e is ApplyChangeFailedEventArgs)
{
ApplyChangeFailedEventArgs args = (ApplyChangeFailedEventArgs)e;
outputText.AppendLine("** APPLY CHANGE FAILURE AT " + site.ToUpper() + " **");
outputText.AppendLine("Table for which failure occurred: " + args.TableMetadata.TableName);
outputText.AppendLine("Error message: " + args.Error.Message);
}
else
{
outputText.AppendLine("Unknown event occurred");
}
streamWriter.WriteLine(DateTime.Now.ToShortTimeString() + " | " + outputText.ToString());
streamWriter.Flush();
streamWriter.Dispose();
}
}
}
Imports System
Imports System.Collections
Imports System.IO
Imports System.Text
Imports System.Data
Imports System.Data.SqlClient
Imports System.Data.SqlServerCe
Imports Microsoft.Synchronization
Imports Microsoft.Synchronization.Data
Imports Microsoft.Synchronization.Data.Server
Imports Microsoft.Synchronization.Data.SqlServerCe
Class Program
Shared Sub Main(ByVal args() As String)
'The Utility class handles all functionality that is not
'directly related to synchronization, such as holding connection
'string information, and making changes to the server and client databases.
Dim util As New Utility()
'The SampleStatsAndProgress class handles information from the
'SyncStatistics object that the Synchronize method returns and
'from SyncAgent events.
Dim sampleStats As New SampleStatsAndProgress()
'Request a password for the client database, and delete
'and re-create the database. The client synchronization
'provider also enables you to create the client database
'if it does not exist.
util.SetClientPassword()
util.RecreateClientDatabase()
'Initial synchronization. Instantiate the SyncAgent
'and call Synchronize.
Dim sampleSyncAgent As New SampleSyncAgent()
Dim syncStatistics As SyncStatistics = sampleSyncAgent.Synchronize()
sampleStats.DisplayStats(syncStatistics, "initial")
'Make changes on the server and client.
util.MakeDataChangesOnServer("Customer")
util.MakeDataChangesOnClient("Customer")
'Subsequent synchronization.
syncStatistics = sampleSyncAgent.Synchronize()
sampleStats.DisplayStats(syncStatistics, "subsequent")
'Make a change at the client that fails when it is
'applied at the server.
util.MakeFailingChangesOnClient()
'Subsequent synchronization.
syncStatistics = sampleSyncAgent.Synchronize()
sampleStats.DisplayStats(syncStatistics, "subsequent")
'Return server data back to its original state.
util.CleanUpServer()
'Exit.
Console.Write(vbLf + "Press Enter to close the window.")
Console.ReadLine()
End Sub 'Main
End Class 'Program
'Create a class that is derived from
'Microsoft.Synchronization.SyncAgent.
Public Class SampleSyncAgent
Inherits SyncAgent
Public Sub New()
'Instantiate a client synchronization provider and specify it
'as the local provider for this synchronization agent.
Me.LocalProvider = New SampleClientSyncProvider()
'Instantiate a server synchronization provider and specify it
'as the remote provider for this synchronization agent.
Me.RemoteProvider = New SampleServerSyncProvider()
'Create two SyncGroups so that changes to OrderHeader
'and OrderDetail are made in one transaction. Depending on
'application requirements, you might include Customer
'in the same group.
Dim customerSyncGroup As New SyncGroup("Customer")
Dim orderSyncGroup As New SyncGroup("Order")
'Add each table: specify a synchronization direction of
'Bidirectional.
Dim customerSyncTable As New SyncTable("Customer")
customerSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable
customerSyncTable.SyncDirection = SyncDirection.Bidirectional
customerSyncTable.SyncGroup = customerSyncGroup
Me.Configuration.SyncTables.Add(customerSyncTable)
Dim orderHeaderSyncTable As New SyncTable("OrderHeader")
orderHeaderSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable
orderHeaderSyncTable.SyncDirection = SyncDirection.Bidirectional
orderHeaderSyncTable.SyncGroup = orderSyncGroup
Me.Configuration.SyncTables.Add(orderHeaderSyncTable)
Dim orderDetailSyncTable As New SyncTable("OrderDetail")
orderDetailSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable
orderDetailSyncTable.SyncDirection = SyncDirection.Bidirectional
orderDetailSyncTable.SyncGroup = orderSyncGroup
Me.Configuration.SyncTables.Add(orderDetailSyncTable)
'Handle the StateChanged and SessionProgress events, and
'display information to the console.
Dim sampleStats As New SampleStatsAndProgress()
AddHandler Me.StateChanged, AddressOf sampleStats.DisplaySessionProgress
AddHandler Me.SessionProgress, AddressOf sampleStats.DisplaySessionProgress
End Sub 'New
End Class 'SampleSyncAgent
'Create a class that is derived from
'Microsoft.Synchronization.Server.DbServerSyncProvider.
Public Class SampleServerSyncProvider
Inherits DbServerSyncProvider
Public Sub New()
'Create a connection to the sample server database.
Dim util As New Utility()
Dim serverConn As New SqlConnection(util.ServerConnString)
Me.Connection = serverConn
'Create a command to retrieve a new anchor value from
'the server. In this case, we use a timestamp value
'that is retrieved and stored in the client database.
'During each synchronization, the new anchor value and
'the last anchor value from the previous synchronization
'are used: the set of changes between these upper and
'lower bounds is synchronized.
'
'SyncSession.SyncNewReceivedAnchor is a string constant;
'you could also use @sync_new_received_anchor directly in
'your queries.
Dim selectNewAnchorCommand As New SqlCommand()
Dim newAnchorVariable As String = "@" + SyncSession.SyncNewReceivedAnchor
With selectNewAnchorCommand
.CommandText = "SELECT " + newAnchorVariable + " = min_active_rowversion() - 1"
.Parameters.Add(newAnchorVariable, SqlDbType.Timestamp)
.Parameters(newAnchorVariable).Direction = ParameterDirection.Output
.Connection = serverConn
End With
Me.SelectNewAnchorCommand = selectNewAnchorCommand
'Create SyncAdapters for each table by using the SqlSyncAdapterBuilder:
' * Specify the base table and tombstone table names.
' * Specify the columns that are used to track when
' and where changes are made.
' * Specify bidirectional synchronization.
' * Call ToSyncAdapter to create the SyncAdapter.
' * Specify a name for the SyncAdapter that matches the
' the name specified for the corresponding SyncTable.
' Do not include the schema names (Sales in this case).
'Customer table
Dim customerBuilder As New SqlSyncAdapterBuilder(serverConn)
With customerBuilder
.TableName = "Sales.Customer"
.TombstoneTableName = customerBuilder.TableName + "_Tombstone"
.SyncDirection = SyncDirection.Bidirectional
.CreationTrackingColumn = "InsertTimestamp"
.UpdateTrackingColumn = "UpdateTimestamp"
.DeletionTrackingColumn = "DeleteTimestamp"
.CreationOriginatorIdColumn = "InsertId"
.UpdateOriginatorIdColumn = "UpdateId"
.DeletionOriginatorIdColumn = "DeleteId"
End With
Dim customerSyncAdapter As SyncAdapter = customerBuilder.ToSyncAdapter()
customerSyncAdapter.TableName = "Customer"
Me.SyncAdapters.Add(customerSyncAdapter)
'OrderHeader table.
Dim orderHeaderBuilder As New SqlSyncAdapterBuilder(serverConn)
With orderHeaderBuilder
.TableName = "Sales.OrderHeader"
.TombstoneTableName = orderHeaderBuilder.TableName + "_Tombstone"
.SyncDirection = SyncDirection.Bidirectional
.CreationTrackingColumn = "InsertTimestamp"
.UpdateTrackingColumn = "UpdateTimestamp"
.DeletionTrackingColumn = "DeleteTimestamp"
.CreationOriginatorIdColumn = "InsertId"
.UpdateOriginatorIdColumn = "UpdateId"
.DeletionOriginatorIdColumn = "DeleteId"
End With
Dim orderHeaderSyncAdapter As SyncAdapter = orderHeaderBuilder.ToSyncAdapter()
orderHeaderSyncAdapter.TableName = "OrderHeader"
Me.SyncAdapters.Add(orderHeaderSyncAdapter)
'OrderDetail table.
Dim orderDetailBuilder As New SqlSyncAdapterBuilder(serverConn)
With orderDetailBuilder
.TableName = "Sales.OrderDetail"
.TombstoneTableName = orderDetailBuilder.TableName + "_Tombstone"
.SyncDirection = SyncDirection.Bidirectional
.CreationTrackingColumn = "InsertTimestamp"
.UpdateTrackingColumn = "UpdateTimestamp"
.DeletionTrackingColumn = "DeleteTimestamp"
.CreationOriginatorIdColumn = "InsertId"
.UpdateOriginatorIdColumn = "UpdateId"
.DeletionOriginatorIdColumn = "DeleteId"
End With
Dim orderDetailSyncAdapter As SyncAdapter = orderDetailBuilder.ToSyncAdapter()
orderDetailSyncAdapter.TableName = "OrderDetail"
Me.SyncAdapters.Add(orderDetailSyncAdapter)
'Log information for the following events.
AddHandler Me.ChangesSelected, AddressOf EventLogger.LogEvents
AddHandler Me.ChangesApplied, AddressOf EventLogger.LogEvents
AddHandler Me.ApplyChangeFailed, AddressOf EventLogger.LogEvents
'Handle the ApplyingChanges event so that we can
'make changes to the dataset.
AddHandler Me.ApplyingChanges, AddressOf SampleServerSyncProvider_ApplyingChanges
End Sub 'New
'Look for inserted rows in the dataset that have a CustomerType
'of Wholesale and update these rows. With access to the dataset,
'you can write any business logic that your application requires.
Private Sub SampleServerSyncProvider_ApplyingChanges(ByVal sender As Object, ByVal e As ApplyingChangesEventArgs)
Dim customerDataTable As DataTable = e.Changes.Tables("Customer")
Dim i As Integer
For i = 1 To customerDataTable.Rows.Count - 1
If customerDataTable.Rows(i).RowState = DataRowState.Added _
AndAlso customerDataTable.Rows(i)("CustomerType") = "Wholesale" Then
customerDataTable.Rows(i)("CustomerType") = "Wholesale (from mobile sales)"
End If
Next i
End Sub
End Class 'SampleServerSyncProvider
'Create a class that is derived from
'Microsoft.Synchronization.Data.SqlServerCe.SqlCeClientSyncProvider.
'You can just instantiate the provider directly and associate it
'with the SyncAgent, but here we use this class to handle client
'provider events.
Public Class SampleClientSyncProvider
Inherits SqlCeClientSyncProvider
Public Sub New()
'Specify a connection string for the sample client database.
Dim util As New Utility()
Me.ConnectionString = util.ClientConnString
'Log information for the following events.
AddHandler Me.SchemaCreated, AddressOf EventLogger.LogEvents
AddHandler Me.ChangesSelected, AddressOf EventLogger.LogEvents
AddHandler Me.ChangesApplied, AddressOf EventLogger.LogEvents
AddHandler Me.ApplyChangeFailed, AddressOf EventLogger.LogEvents
'Use the following events to fix up schema on the client.
'We use the CreatingSchema event to change the schema
'by using the API. We use the SchemaCreated event
'to change the schema by using SQL.
'Note that both schema events fire for the Customer table,
'even though we already created the table. This allows us
'to work with the table at this point if we have to.
AddHandler Me.CreatingSchema, AddressOf SampleClientSyncProvider_CreatingSchema
AddHandler Me.SchemaCreated, AddressOf SampleClientSyncProvider_SchemaCreated
End Sub 'New
Private Sub SampleClientSyncProvider_CreatingSchema(ByVal sender As Object, ByVal e As CreatingSchemaEventArgs)
Dim tableName As String = e.Table.TableName
If tableName = "Customer" Then
'Set the RowGuid property because it is not copied
'to the client by default. This is also a good time
'to specify literal defaults with .Columns[ColName].DefaultValue,
'but we will specify defaults like NEWID() by calling
'ALTER TABLE after the table is created.
e.Schema.Tables("Customer").Columns("CustomerId").RowGuid = True
End If
If tableName = "OrderHeader" Then
e.Schema.Tables("OrderHeader").Columns("OrderId").RowGuid = True
End If
End Sub 'SampleClientSyncProvider_CreatingSchema
Private Sub SampleClientSyncProvider_SchemaCreated(ByVal sender As Object, ByVal e As SchemaCreatedEventArgs)
Dim tableName As String = e.Table.TableName
Dim util As New Utility()
'Call ALTER TABLE on the client. This must be done
'over the same connection and within the same
'transaction that Synchronization Services uses
'to create the schema on the client.
If tableName = "Customer" Then
util.MakeSchemaChangesOnClient(e.Connection, e.Transaction, "Customer")
End If
If tableName = "OrderHeader" Then
util.MakeSchemaChangesOnClient(e.Connection, e.Transaction, "OrderHeader")
End If
If tableName = "OrderDetail" Then
util.MakeSchemaChangesOnClient(e.Connection, e.Transaction, "OrderDetail")
End If
End Sub 'SampleClientSyncProvider_SchemaCreated
End Class 'SampleClientSyncProvider
'Handle SyncAgent events and the statistics that are returned by the SyncAgent.
Public Class SampleStatsAndProgress
Public Sub DisplayStats(ByVal syncStatistics As SyncStatistics, ByVal syncType As String)
Console.WriteLine(String.Empty)
If syncType = "initial" Then
Console.WriteLine("****** Initial Synchronization Stats ******")
ElseIf syncType = "subsequent" Then
Console.WriteLine("***** Subsequent Synchronization Stats ****")
End If
Console.WriteLine("Start Time: " & syncStatistics.SyncStartTime)
Console.WriteLine("Upload Changes Applied: " & syncStatistics.UploadChangesApplied)
Console.WriteLine("Upload Changes Failed: " & syncStatistics.UploadChangesFailed)
Console.WriteLine("Total Changes Uploaded: " & syncStatistics.TotalChangesUploaded)
Console.WriteLine("Download Changes Applied: " & syncStatistics.DownloadChangesApplied)
Console.WriteLine("Download Changes Failed: " & syncStatistics.DownloadChangesFailed)
Console.WriteLine("Total Changes Downloaded: " & syncStatistics.TotalChangesDownloaded)
Console.WriteLine("Complete Time: " & syncStatistics.SyncCompleteTime)
Console.WriteLine(String.Empty)
End Sub 'DisplayStats
Public Sub DisplaySessionProgress(ByVal sender As Object, ByVal e As EventArgs)
Dim outputText As New StringBuilder()
If TypeOf e Is SessionStateChangedEventArgs Then
Dim args As SessionStateChangedEventArgs = CType(e, SessionStateChangedEventArgs)
If args.SessionState = SyncSessionState.Synchronizing Then
outputText.AppendLine(String.Empty)
outputText.Append("** SyncAgent is synchronizing")
Else
outputText.Append("** SyncAgent is ready to synchronize")
End If
ElseIf TypeOf e Is SessionProgressEventArgs Then
Dim args As SessionProgressEventArgs = CType(e, SessionProgressEventArgs)
outputText.Append("Percent complete: " & args.PercentCompleted & " (" & args.SyncStage.ToString() & ")")
Else
outputText.AppendLine("Unknown event occurred")
End If
Console.WriteLine(outputText.ToString())
End Sub 'DisplaySessionProgress
End Class 'SampleStatsAndProgress
Public Class EventLogger
'Create client and server log files, and write to them
'based on data from several EventArgs classes.
Public Shared Sub LogEvents(ByVal sender As Object, ByVal e As EventArgs)
Dim logFile As String = String.Empty
Dim site As String = String.Empty
If TypeOf sender Is SampleServerSyncProvider Then
logFile = "ServerLogFile.txt"
site = "server"
ElseIf TypeOf sender Is SampleClientSyncProvider Then
logFile = "ClientLogFile.txt"
site = "client"
End If
Dim streamWriter As StreamWriter = File.AppendText(logFile)
Dim outputText As New StringBuilder()
If TypeOf e Is ChangesSelectedEventArgs Then
Dim args As ChangesSelectedEventArgs = CType(e, ChangesSelectedEventArgs)
outputText.AppendLine("Client ID: " & args.Session.ClientId.ToString())
outputText.AppendLine("Changes selected from " & site & " for group " & args.GroupMetadata.GroupName)
outputText.AppendLine("Inserts selected from " & site & " for group: " & args.Context.GroupProgress.TotalInserts.ToString())
outputText.AppendLine("Updates selected from " & site & " for group: " & args.Context.GroupProgress.TotalUpdates.ToString())
outputText.AppendLine("Deletes selected from " & site & " for group: " & args.Context.GroupProgress.TotalDeletes.ToString())
ElseIf TypeOf e Is ChangesAppliedEventArgs Then
Dim args As ChangesAppliedEventArgs = CType(e, ChangesAppliedEventArgs)
outputText.AppendLine("Client ID: " & args.Session.ClientId.ToString())
outputText.AppendLine("Changes applied to " & site & " for group " & args.GroupMetadata.GroupName)
outputText.AppendLine("Inserts applied to " & site & " for group: " & args.Context.GroupProgress.TotalInserts.ToString())
outputText.AppendLine("Updates applied to " & site & " for group: " & args.Context.GroupProgress.TotalUpdates.ToString())
outputText.AppendLine("Deletes applied to " & site & " for group: " & args.Context.GroupProgress.TotalDeletes.ToString())
ElseIf TypeOf e Is SchemaCreatedEventArgs Then
Dim args As SchemaCreatedEventArgs = CType(e, SchemaCreatedEventArgs)
outputText.AppendLine("Schema creation for group: " & args.Table.SyncGroup.GroupName)
outputText.AppendLine("Table: " & args.Table.TableName)
outputText.AppendLine("Direction : " & args.Table.SyncDirection)
outputText.AppendLine("Creation Option: " & args.Table.CreationOption)
ElseIf TypeOf e Is ApplyChangeFailedEventArgs Then
Dim args As ApplyChangeFailedEventArgs = CType(e, ApplyChangeFailedEventArgs)
outputText.AppendLine("** APPLY CHANGE FAILURE AT " & site.ToUpper() & " **")
outputText.AppendLine("Table for which failure occurred: " & args.TableMetadata.TableName)
outputText.AppendLine("Error message: " & args.Error.Message)
Else
outputText.AppendLine("Unknown event occurred")
End If
streamWriter.WriteLine(DateTime.Now.ToShortTimeString() + " | " + outputText.ToString())
streamWriter.Flush()
streamWriter.Dispose()
End Sub 'LogEvents
End Class 'EventLogger