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DtsEventHandlerEnumerator.Current Properti

Definisi

Mendapatkan elemen saat ini dalam koleksi.

public:
 property Microsoft::SqlServer::Dts::Runtime::DtsEventHandler ^ Current { Microsoft::SqlServer::Dts::Runtime::DtsEventHandler ^ get(); };
public Microsoft.SqlServer.Dts.Runtime.DtsEventHandler Current { get; }
member this.Current : Microsoft.SqlServer.Dts.Runtime.DtsEventHandler
Public ReadOnly Property Current As DtsEventHandler

Nilai Properti

Elemen saat ini dalam koleksi.

Contoh

Sampel kode berikut membuat dua penanganan aktivitas untuk paket. Untuk satu penanganan aktivitas, dua tugas ditambahkan. DtsEventHandlerEnumerator Kemudian dibuat, dan menggunakan Current metode dan MoveNext untuk menavigasi koleksi.

using System;  
using System.Collections.Generic;  
using System.Text;  
using Microsoft.SqlServer.Dts.Runtime;  
using Microsoft.SqlServer.Dts.Tasks.SendMailTask;  
using Microsoft.SqlServer.Dts.Tasks.BulkInsertTask;  

namespace DtsEventHandler_API  
{  
    class Program  
    {  
        static void Main(string[] args)  
        {  
            Package pkg = new Package();  

            // Set up a DtsEventHandler for the OnError event of the package.  
            DtsEventHandler dtsEHOE = (DtsEventHandler)pkg.EventHandlers.Add("OnError");  
            DtsEventHandler dtsEHW = (DtsEventHandler)pkg.EventHandlers.Add("OnWarning");  

            // When an OnError Event occurs, the Executables collection contains  
            // the items to run. For this example, there will be a SendMailtTask  
            // and a BulkInsertTask with a precedence constraint between them.  
            Executable dtsEH1 = dtsEHOE.Executables.Add("STOCK:SendMailTask");  
            TaskHost th = (TaskHost)dtsEH1;  
            SendMailTask smTask = (SendMailTask)th.InnerObject;  
            smTask.Subject = "Send Mail task";  

            // Add a second executable to the DtsEventHandler.  
            Executable dtsEH2 = dtsEHOE.Executables.Add("STOCK:BulkInsertTask");  
            TaskHost th2 = (TaskHost)dtsEH2;  

            //Create the Enumerator. Since we added the DtsEventhandler to the   
            // package, then that's where to get the EventHandlers collection.  
            DtsEventHandlerEnumerator myEnum = pkg.EventHandlers.GetEnumerator();  
            Console.WriteLine("The collection contains the following values:");  
            int i = 0;  
            while ((myEnum.MoveNext()) && (myEnum.Current != null))  
                Console.WriteLine("[{0}] {1}", i++, myEnum.Current.Name);  
        }  
    }  
}  
Imports System  
Imports System.Collections.Generic  
Imports System.Text  
Imports Microsoft.SqlServer.Dts.Runtime  
Imports Microsoft.SqlServer.Dts.Tasks.SendMailTask  
Imports Microsoft.SqlServer.Dts.Tasks.BulkInsertTask  

Namespace DtsEventHandler_API  
    Class Program  
        Shared  Sub Main(ByVal args() As String)  
            Dim pkg As Package =  New Package()   

            ' Set up a DtsEventHandler for the OnError event of the package.  
            Dim dtsEHOE As DtsEventHandler = CType(pkg.EventHandlers.Add("OnError"), DtsEventHandler)  
            Dim dtsEHW As DtsEventHandler = CType(pkg.EventHandlers.Add("OnWarning"), DtsEventHandler)  

            ' When an OnError Event occurs, the Executables collection contains  
            ' the items to run. For this example, there will be a SendMailtTask  
            ' and a BulkInsertTask with a precedence constraint between them.  
            Dim dtsEH1 As Executable =  dtsEHOE.Executables.Add("STOCK:SendMailTask")   
            Dim th As TaskHost = CType(dtsEH1, TaskHost)  
            Dim smTask As SendMailTask = CType(th.InnerObject, SendMailTask)  
            smTask.Subject = "Send Mail task"  

            ' Add a second executable to the DtsEventHandler.  
            Dim dtsEH2 As Executable =  dtsEHOE.Executables.Add("STOCK:BulkInsertTask")   
            Dim th2 As TaskHost = CType(dtsEH2, TaskHost)  

            'Create the Enumerator. Since we added the DtsEventhandler to the   
            ' package, then that's where to get the EventHandlers collection.  
            Dim myEnum As DtsEventHandlerEnumerator =  pkg.EventHandlers.GetEnumerator()   
            Console.WriteLine("The collection contains the following values:")  
            Dim i As Integer =  0   
            While (myEnum.MoveNext()) &&(myEnum.Current <> Nothing)  
            Console.WriteLine("[{0}] {1}",i = Console.WriteLine("[{0}] {1}",i + 1  
            End While  
        End Sub  
    End Class  
End Namespace  

Contoh Output:

Koleksi berisi nilai berikut:

[0] OnError

[1] OnWarning

Keterangan

Setelah enumerator dibuat, atau setelah panggilan ke Reset metode , MoveNext metode harus dipanggil untuk memajukan enumerator ke elemen pertama koleksi sebelum membaca nilai Current properti; jika tidak, Current tidak terdefinisi dan melempar pengecualian.

Current juga melempar pengecualian jika panggilan terakhir untuk MoveNext dikembalikan false, yang menunjukkan akhir koleksi.

Current tidak memindahkan posisi enumerator, dan panggilan berturut-turut untuk Current mengembalikan objek yang sama sampai atau MoveNextReset dipanggil.

Enumerator tetap valid selama koleksi tetap tidak berubah. Jika perubahan dilakukan pada koleksi, seperti menambahkan, memodifikasi, atau menghapus elemen, enumerator tidak valid dan menjadi tidak dapat dipulihkan; dengan demikian, panggilan berikutnya ke MoveNext atau Reset melempar InvalidOperationException. Jika koleksi dimodifikasi antara panggilan ke MoveNext dan Current, Current mengembalikan elemen yang diatur ke, bahkan jika enumerator telah dibatalkan.

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