VariableEnumerator.Current Properti

Definisi

Ruang nama:

Microsoft.SqlServer.Dts.Runtime

Rakitan:

Microsoft.SqlServer.ManagedDTS.dll

Mendapatkan objek saat ini Variable dari koleksi.

public:
 property Microsoft::SqlServer::Dts::Runtime::Variable ^ Current { Microsoft::SqlServer::Dts::Runtime::Variable ^ get(); };

public Microsoft.SqlServer.Dts.Runtime.Variable Current { get; }

member this.Current : Microsoft.SqlServer.Dts.Runtime.Variable

Public ReadOnly Property Current As Variable

Nilai Properti

Variable

Objek saat ini Variable .

Contoh

Contoh kode berikut menambahkan variabel ke paket. Contoh kode menggunakan berbagai metode untuk menemukan variabel dan mencetak nama, nilai, dan namespace.

using System;  
using System.Collections.Generic;  
using System.Text;  
using Microsoft.SqlServer.Dts.Runtime;  
namespace Adding_Variables  
{  
    class Program  
    {  
        static void Main(string[] args)  
        {  
            Application app = new Application();  
            // Load a sample package that contains a variable that sets the File Name.  
            Package pkg = app.LoadPackage(@"C:\Program Files\Microsoft SQL Server\100\Samples\Integration Services\Package Samples\CalculatedColumns Sample\CalculatedColumns\CalculatedColumns.dtsx", null);  
            Variables pkgVars = pkg.Variables;  
            Variable myVar = pkg.Variables.Add("myCustomVar", false, "User", "3");  

            // See if the variable is in the collection now.  
            Boolean hasMyVar = pkg.Variables.Contains("myCustomVar");  
            Console.WriteLine("The variable was found? {0}", hasMyVar);  

            // Loop over the collection using foreach keyword.  
            foreach (Variable pkgVar in pkgVars)  
            {  
                // Only print variables from the User namespace.  
                if (pkgVar.Namespace == "User")  
                {  
                Console.WriteLine("Variable: {0}, {1}", pkgVar.Name, pkgVar.Value.ToString());  
                 }  
            }  
            Console.WriteLine("---------------------------");  
            // Loop over the collection using the Enumerator.   
            VariableEnumerator myEnum = pkg.Variables.GetEnumerator();  
            int i = 0;  
            while ((myEnum.MoveNext()) && (myEnum.Current != null))  
                // Again only show User namespace variables.  
                if (myEnum.Current.Namespace == "User")  
                {                  
                    Console.WriteLine("[{0}] {1}, {2}", i++, myEnum.Current.Name, myEnum.Current.Namespace);  
                }  

            myEnum.Reset();  
            Console.WriteLine("---------------------------");  

            //Using the Item method syntax of [x], obtain the  
            // first entry in the collection.  
            myVar = pkgVars[0];  
            Console.WriteLine("The name and namespace of the first variable is: {0}, {1}", myVar.Name, myVar.Namespace);  
            String nameOfFirstItem = pkgVars[0].Name;  
            Console.WriteLine("The name of the first variable is: {0}", nameOfFirstItem);  
            //}  
        }  
    }  
}  

Imports System  
Imports System.Collections.Generic  
Imports System.Text  
Imports Microsoft.SqlServer.Dts.Runtime  

Namespace Adding_Variables  
    Class Program  
        Shared  Sub Main(ByVal args() As String)  
            Dim app As Application =  New Application()   
            ' Load a sample package that contains a variable that sets the File Name.  
            Dim pkg As Package =  app.LoadPackage("C:\Program Files\Microsoft SQL Server\100\Samples\Integration Services\Package Samples\CalculatedColumns Sample\CalculatedColumns\CalculatedColumns.dtsx",Nothing)   
            Dim pkgVars As Variables =  pkg.Variables   
            Dim myVar As Variable =  pkg.Variables.Add("myCustomVar",False,"User","3")   

            ' See if the variable is in the collection now.  
            Dim hasMyVar As Boolean =  pkg.Variables.Contains("myCustomVar")   
            Console.WriteLine("The variable was found? {0}", hasMyVar)  

            ' Loop over the collection using foreach keyword.  
            Dim pkgVar As Variable  
            For Each pkgVar In pkgVars  
                ' Only print variables from the User namespace.  
                If pkgVar.Namespace = "User" Then  
                Console.WriteLine("Variable: {0}, {1}", pkgVar.Name, pkgVar.Value.ToString())  
                End If  
            Next  
            Console.WriteLine("---------------------------")  
            ' Loop over the collection using the Enumerator.   
            Dim myEnum As VariableEnumerator =  pkg.Variables.GetEnumerator()   
            Dim i As Integer =  0   
            While (myEnum.MoveNext()) &&(myEnum.Current <> Nothing)  
                    Console.WriteLine("[{0}] {1}, {2}",i = Console.WriteLine("[{0}] {1}, {2}",i + 1  
            End While  

            myEnum.Reset()  
            Console.WriteLine("---------------------------")  

            'Using the Item method syntax of [x], obtain the  
            ' first entry in the collection.  
            myVar = pkgVars(0)  
            Console.WriteLine("The name and namespace of the first variable is: {0}, {1}", myVar.Name, myVar.Namespace)  
            Dim nameOfFirstItem As String =  pkgVars(0).Name   
            Console.WriteLine("The name of the first variable is: {0}", nameOfFirstItem)  
            '}  
        End Sub  
    End Class  
End Namespace  

Contoh Output:

Variabel ditemukan? True

Variabel: myCustomVar, 3

---------------------------

[0] myCustomVar, Pengguna

---------------------------

Nama dan namespace variabel pertama adalah: CancelEvent, System

Nama variabel pertama adalah: CancelEvent

Keterangan

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

Current juga melemparkan 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 hingga 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. Namun, jika koleksi dimodifikasi antara panggilan ke MoveNext dan Current, Current mengembalikan elemen yang diatur ke, bahkan jika enumerator telah dibatalkan.