PropertyEnumerator.Current Property

Статья
12/15/2008

Returns the current DtsProperty element in the collection.

Пространство имен: Microsoft.SqlServer.Dts.Runtime
Сборка: Microsoft.SqlServer.ManagedDTS (in microsoft.sqlserver.manageddts.dll)

Синтаксис

'Декларация
Public ReadOnly Property Current As DtsProperty

public DtsProperty Current { get; }

public:
property DtsProperty^ Current {
    DtsProperty^ get ();
}

/** @property */
public DtsProperty get_Current ()

public function get Current () : DtsProperty

Значение свойства

A DtsProperty object.

Замечания

After an enumerator is created, or after a call to the Reset method, the MoveNext method must be called to advance the enumerator to the first element of the collection before the enumerator can read the value of the Current property; otherwise, Current is undefined and throws an exception.

Current also throws an exception if the last call to MoveNext returned false, which indicates the end of the collection.

Current does not move the position of the enumerator, and consecutive calls to Current return the same object until either MoveNext or Reset is called.

An enumerator remains valid as long as the collection remains unchanged. If changes are made to the collection, such as adding, modifying, or deleting elements, the enumerator is invalidated and becomes irrecoverable; thus, the next call to MoveNext or Reset throws an InvalidOperationException. However, if the collection is modified between calls to MoveNext and Current, Current returns the element that it is set to, even if the enumerator has been invalidated.

Пример

The following code sample creates a PropertyEnumerator, then shows the use of the MoveNext and Current methods to move over the collection.

using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.SqlServer.Dts.Runtime;

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

            // Get the Properties collection from the package.
            // This shows the default properties set on new packages.
            DtsProperties pkgProperties = pkg.Properties;

           // Create the enumerator.
            PropertyEnumerator myEnumerator = pkgProperties.GetEnumerator();

            // Show the use of the Contains method.
            Boolean containsCertObj = pkgProperties.Contains("CertificateObject");
            Console.WriteLine("Contains CertificateObject? {0}", containsCertObj);

            // Show the use of the item[x] syntax.
            String aName = pkgProperties[5].Name;
            Console.WriteLine("Property 5 is {0}", aName);

            // Show the use of the MoveNext and Current methods.
            int i = 0;
            while ((myEnumerator.MoveNext()) && (myEnumerator.Current != null))
            {
                Console.WriteLine("[{0}] {1}", i++, myEnumerator.Current.Name);
            }
        }
    }
}

Imports System
Imports System.Collections.Generic
Imports System.Text
Imports Microsoft.SqlServer.Dts.Runtime
 
Namespace DtsProperties_API
    Class Program
        Shared  Sub Main(ByVal args() As String)
            Dim pkg As Package =  New Package() 
 
            ' Get the Properties collection from the package.
            ' This shows the default properties set on new packages.
            Dim pkgProperties As DtsProperties =  pkg.Properties 
 
           ' Create the enumerator.
            Dim myEnumerator As PropertyEnumerator =  pkgProperties.GetEnumerator() 
 
            ' Show the use of the Contains method.
            Dim containsCertObj As Boolean =  pkgProperties.Contains("CertificateObject") 
            Console.WriteLine("Contains CertificateObject? {0}", containsCertObj)
 
            ' Show the use of the item[x] syntax.
            Dim aName As String =  pkgProperties(5).Name 
            Console.WriteLine("Property 5 is {0}", aName)
 
            ' Show the use of the MoveNext and Current methods.
            Dim i As Integer =  0 
            While (myEnumerator.MoveNext()) &&(myEnumerator.Current <> Nothing)
                Console.WriteLine("[{0}] {1}",i = Console.WriteLine("[{0}] {1}",i + 1
            End While
        End Sub
    End Class
End Namespace

Sample Output:

Contains CertificateObject? True

Property 5 is Configurations

[0] CertificateContext

[1] CertificateObject

[2] CheckpointFileName

[3] CheckpointUsage

[4] CheckSignatureOnLoad

[5] Configurations

[6] Connections

[7] CreationDate

[8] CreationName

[9] CreatorComputerName

[10] CreatorName

[11] DelayValidation

. . .

[63] VersionGUID

[64] VersionMajor

[65] VersionMinor

[66] Warnings

Синхронизация потоков

Any public static (Shared in Microsoft Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Платформы

Платформы разработки

Список поддерживаемых платформ см. в разделе Hardware and Software Requirements for Installing SQL Server 2005.

Целевые платформы