SqlCeClientSyncProvider-Klasse
Abstrahiert einen Clientsynchronisierungsanbieter für SQL Server Compact, der mit dem Client kommuniziert und den Synchronisierungs-Agent vor der spezifischen Implementierung der Clientdatenbank abschirmt.
Namespace: Microsoft.Synchronization.Data.SqlServerCe
Assembly: Microsoft.Synchronization.Data.SqlServerCe (in Microsoft.Synchronization.Data.SqlServerCe.dll)
Syntax
'Declaration
Public Class SqlCeClientSyncProvider _
Inherits ClientSyncProvider
'Usage
Dim instance As SqlCeClientSyncProvider
public class SqlCeClientSyncProvider : ClientSyncProvider
public ref class SqlCeClientSyncProvider : public ClientSyncProvider
type SqlCeClientSyncProvider =
class
inherit ClientSyncProvider
end
public class SqlCeClientSyncProvider extends ClientSyncProvider
Hinweise
Der Clientsynchronisierungsanbieter hat hauptsächlich die folgenden Aufgaben:
Speichern von Informationen zu Tabellen auf dem Client, die für die Synchronisierung aktiviert sind
Abrufen von Änderungen, die seit der letzten Synchronisierung in der Clientdatenbank vorgenommen wurden
Übernehmen inkrementeller Änderungen für die Clientdatenbank
Erkennen sich widersprechender Änderungen
Beispiele
Das folgende Codebeispiel erstellt eine Klasse, die von der SqlCeClientSyncProvider-Klasse abgeleitet ist. Die Klasse erstellt eine Verbindung mit der Clientdatenbank und behandelt eine Reihe häufiger Ereignisse, darunter die Schemaerstellung in der Clientdatenbank. Eine Darstellung dieses Codes im Kontext eines vollständigen Beispiels finden Sie unter Vorgehensweise: Arbeiten mit Ereignissen und Programmgeschäftslogik.
public class SampleClientSyncProvider : SqlCeClientSyncProvider
{
public SampleClientSyncProvider()
{
//Specify a connection string for the sample client database.
Utility util = new Utility();
this.ConnectionString = Utility.ConnStr_SqlCeClientSync;
//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 Sync Framework uses
//to create the schema on the client.
if (tableName == "Customer")
{
Utility.MakeSchemaChangesOnClient(e.Connection, e.Transaction, "Customer");
}
if (tableName == "OrderHeader")
{
Utility.MakeSchemaChangesOnClient(e.Connection, e.Transaction, "OrderHeader");
}
if (tableName == "OrderDetail")
{
Utility.MakeSchemaChangesOnClient(e.Connection, e.Transaction, "OrderDetail");
}
}
}
Public Class SampleClientSyncProvider
Inherits SqlCeClientSyncProvider
Public Sub New()
'Specify a connection string for the sample client database.
Dim util As New Utility()
Me.ConnectionString = Utility.ConnStr_SqlCeClientSync
'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 Sync Framework uses
'to create the schema on the client.
If tableName = "Customer" Then
Utility.MakeSchemaChangesOnClient(e.Connection, e.Transaction, "Customer")
End If
If tableName = "OrderHeader" Then
Utility.MakeSchemaChangesOnClient(e.Connection, e.Transaction, "OrderHeader")
End If
If tableName = "OrderDetail" Then
Utility.MakeSchemaChangesOnClient(e.Connection, e.Transaction, "OrderDetail")
End If
End Sub 'SampleClientSyncProvider_SchemaCreated
End Class 'SampleClientSyncProvider
Vererbungshierarchie
System. . :: . .Object
Microsoft.Synchronization. . :: . .SyncProvider
Microsoft.Synchronization.Data. . :: . .ClientSyncProvider
Microsoft.Synchronization.Data.SqlServerCe..::..SqlCeClientSyncProvider
Threadsicherheit
Alle öffentlichen static (Shared in Visual Basic) Member dieses Typs sind threadsicher. Bei Instanzmembern ist die Threadsicherheit nicht gewährleistet.