處理 SMO 事件

有些伺服器事件類型可以藉由事件處理常式和 ServerConnection 物件進行訂閱。

SQL Server 管理物件 (SMO) 中的許多執行個體類別，都會在伺服器上發生特定動作時觸發事件。

這些事件可以藉由設定事件處理常式及訂閱相關事件，以程式設計的方式來處理。這種事件處理類型是暫時性的，因為當 SMO 用戶端程式結束時會將訂閱全數移除。

ConnectionContext 事件處理

ServerConnection 物件支援數種事件類型。事件屬性必須設定為具有適當事件處理常式的執行個體，而事件處理常式物件則必須定義為可以處理事件的受保護函數。

事件訂閱

您可藉由下列步驟來處理事件：撰寫事件處理常式類別、建立其執行個體、將事件處理常式指派給父物件，然後再訂閱事件。

您必須撰寫事件處理常式類別，才能處理事件。事件處理常式類別可以包含一個以上的事件處理常式函數，而且必須加以安裝，才能處理事件。事件處理常式函數會從可用於報告事件相關資訊的 ServerEventNotificatificationArgs 參數接收事件的相關資訊。

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

範例

如果要使用所提供的任何程式碼範例，您必須選擇建立應用程式用的程式設計環境、程式設計範本，及程式設計語言。如需詳細資訊，請參閱《SQL Server 線上叢書》中的＜如何：在 Visual Studio .NET 中建立 Visual Basic SMO 專案＞(英文) 或＜如何：在 Visual Studio .NET 中建立 Visual C# SMO 專案＞(英文)。

在 Visual Basic 中註冊事件處理常式及訂閱事件處理

此程式碼範例示範如何設定事件處理常式，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 AdventureWorks 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 AdventureWorks database.")
End Sub
Sub Main()
    'Connect to the local, default instance of SQL Server.
    Dim srv As Server
    srv = New Server
    'Reference the AdventureWorks database.
    Dim db As Database
    db = srv.Databases("AdventureWorks")
    '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 occured.
    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

在 Visual C# 中註冊事件處理常式及訂閱事件處理

此程式碼範例示範如何設定事件處理常式，以及如何訂閱資料庫事件。

//Create an event handler subroutine that runs when a table is created. 
private void MyCreateEventHandler(object sender, ServerEventArgs e) 
{ 
Console.WriteLine("A table has just been added to the AdventureWorks 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 AdventureWorks database."); 
} 
public void Main() 
{ 
//Connect to the local, default instance of SQL Server. 
Server srv; 
srv = new Server(); 
//Reference the AdventureWorks database. 
Database db; 
db = srv.Databases("AdventureWorks"); 
//Create a database event set that contains the CreateTable event only. 
DatabaseEventSet databaseCreateEventSet = new DatabaseEventSet(); 
databaseCreateEventSet.CreateTable = true; 
//Create a server event handler and set it to the first event handler subroutine. 
ServerEventHandler serverCreateEventHandler; 
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. 
DatabaseEventSet databaseDropEventSet = new DatabaseEventSet(); 
databaseDropEventSet.DropTable = true; 
//Create a server event handler and set it to the second event handler subroutine. 
ServerEventHandler serverDropEventHandler; 
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. 
Table tb; 
tb = new Table(db, "Test_Table"); 
Column mycol1; 
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 occured. 
int x; 
int y; 
for (x = 1; x <= 1000000000; x++) { 
    y = x * 2; 
} 
//Stop event handling. 
db.Events.StopEvents(); 
}