處理 SMO 事件

適用於：sql ServerAzure SQL 資料庫 Azure SQL 受控執行個體 Microsoft Fabric 中的 Azure Synapse Analytics SQL 資料庫

您可以使用事件處理程式和 ServerConnection 物件來訂閱伺服器事件類型。

當伺服器上發生特定動作時，SQL Server 管理物件 （SMO） 中的許多實例類別都可以觸發事件。

設定事件處理程式並訂閱相關聯的事件，即可以程式設計方式處理這些事件。 這種類型的事件處理是暫時性的，因為 SMO 用戶端程式結束時會移除所有訂閱。

ConnectionContext 事件處理

物件 ServerConnection 支援數種事件類型。 事件屬性必須設定為適當事件處理程序的實例，而且事件處理程式對象必須定義為處理事件的受保護函式。

事件訂閱

您可以撰寫事件處理程序類別、建立它的實例、將事件處理程式指派給父對象，然後訂閱事件，以處理事件。

事件處理程式類別必須寫入以處理事件。 事件處理程式類別可以包含多個事件處理程式函式，而且必須安裝才能處理的事件。 事件處理程式函式會從 ServerEventNotificatificationArgs 參數接收事件的相關信息，可用來報告事件的相關信息。

可以處理的資料庫和伺服器事件類型會列在 類別和ServerEventSet類別中DatabaseEventSet。

範例

若要使用提供的任何程式代碼範例，您必須選擇程式設計環境、程式設計範本，以及用來建立應用程式的程式設計語言。 如需詳細資訊，請參閱 如何在Visual Studio .NET 中建立Visual C# SMO 專案。

註冊事件處理程式，並訂閱 .NET 中的事件處理

下列程式代碼範例示範如何在 .NET 中設定事件處理程式，以及如何訂閱資料庫事件。

'Create an event handler subroutine that runs when a table is created.
Private Sub MyCreateEventHandler(ByVal sender As Object, ByVal e As ServerEventArgs)
    Console.WriteLine("A table has just been added to the AdventureWorks2022 database.")
End Sub

'Create an event handler subroutine that runs when a table is deleted.
Private Sub MyDropEventHandler(ByVal sender As Object, ByVal e As ServerEventArgs)
    Console.WriteLine("A table has just been dropped from the AdventureWorks2022 database.")
End Sub

Sub Main()
    'Connect to the local, default instance of SQL Server.

    Dim srv As Server
    srv = New Server

    'Reference the AdventureWorks2022 database.
    Dim db As Database
    db = srv.Databases("AdventureWorks2022")

    'Create a database event set that contains the CreateTable event only.
    Dim databaseCreateEventSet As New DatabaseEventSet
    databaseCreateEventSet.CreateTable = True

    'Create a server event handler and set it to the first event handler subroutine.
    Dim serverCreateEventHandler As ServerEventHandler
    serverCreateEventHandler = New ServerEventHandler(AddressOf MyCreateEventHandler)

    'Subscribe to the first server event handler when a CreateTable event occurs.
    db.Events.SubscribeToEvents(databaseCreateEventSet, serverCreateEventHandler)

    'Create a database event set that contains the DropTable event only.
    Dim databaseDropEventSet As New DatabaseEventSet
    databaseDropEventSet.DropTable = True

    'Create a server event handler and set it to the second event handler subroutine.
    Dim serverDropEventHandler As ServerEventHandler
    serverDropEventHandler = New ServerEventHandler(AddressOf MyDropEventHandler)

    'Subscribe to the second server event handler when a DropTable event occurs.
    db.Events.SubscribeToEvents(databaseDropEventSet, serverDropEventHandler)

    'Start event handling.
    db.Events.StartEvents()

    'Create a table on the database.
    Dim tb As Table
    tb = New Table(db, "Test_Table")

    Dim mycol1 As Column
    mycol1 = New Column(tb, "Name", DataType.NChar(50))
    mycol1.Collation = "Latin1_General_CI_AS"
    mycol1.Nullable = True

    tb.Columns.Add(mycol1)
    tb.Create()

    'Remove the table.
    tb.Drop()

    'Wait until the events have occurred.
    Dim x As Integer
    Dim y As Integer
    For x = 1 To 1000000000
        y = x*2
    Next

    'Stop event handling.
    db.Events.StopEvents()
End Sub

//Create an event handler subroutine that runs when a table is created.
private void MyCreateEventHandler(object sender, ServerEventArgs e)
{
    Console.WriteLine("A table has just been added to the AdventureWorks2022 database.");
}

//Create an event handler subroutine that runs when a table is deleted.
private void MyDropEventHandler(object sender, ServerEventArgs e)
{
    Console.WriteLine("A table has just been dropped from the AdventureWorks2022 database.");
}

public void Main()
{
    //Connect to the local, default instance of SQL Server.
    var srv = new Server();

    //Reference the AdventureWorks2022 database.
    Database db = srv.Databases["AdventureWorks2022"];

    //Create a database event set that contains the CreateTable event only.
    var databaseCreateEventSet = new DatabaseEventSet
    {
        CreateTable = true
    };

    //Create a server event handler and set it to the first event handler subroutine.
    var serverCreateEventHandler = new ServerEventHandler(MyCreateEventHandler);

    //Subscribe to the first server event handler when a CreateTable event occurs.
    db.Events.SubscribeToEvents(databaseCreateEventSet, serverCreateEventHandler);

    //Create a database event set that contains the DropTable event only.
    var databaseDropEventSet = new DatabaseEventSet
    {
        DropTable = true
    };

    //Create a server event handler and set it to the second event handler subroutine.
    var serverDropEventHandler = new ServerEventHandler(MyDropEventHandler);

    //Subscribe to the second server event handler when a DropTable event occurs.
    db.Events.SubscribeToEvents(databaseDropEventSet, serverDropEventHandler);
    
    //Start event handling.
    db.Events.StartEvents();

    //Create a table on the database.
    var tb = new Table(db, "Test_Table");

    var myCol1 = new Column(tb, "Name", DataType.NChar(50))
    {
        Collation = "Latin1_General_CI_AS",
        Nullable = true
    };

    tb.Columns.Add(myCol1);
    tb.Create();

    //Remove the table.
    tb.Drop();
    
    //Wait until the events have occurred.
    int x;
    int y;
    for (x = 1; x <= 1000000000; x++)
    {
        y = x * 2;
    }

    //Stop event handling.
    db.Events.StopEvents();
}