ExtendedPropertyEnumerator.Current Property
Returns the current ExtendedProperty object from the collection.
Espacio de nombres: Microsoft.SqlServer.Dts.Runtime
Ensamblado: Microsoft.SqlServer.ManagedDTS (in microsoft.sqlserver.manageddts.dll)
Sintaxis
'Declaración
Public ReadOnly Property Current As ExtendedProperty
public ExtendedProperty Current { get; }
public:
property ExtendedProperty^ Current {
ExtendedProperty^ get ();
}
/** @property */
public ExtendedProperty get_Current ()
public function get Current () : ExtendedProperty
Valor de propiedad
The current ExtendedProperty object.
Notas
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. 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.
Ejemplo
The following code sample creates an enumerator, and then uses the Current and MoveNext methods to navigate over the collection.
using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.SqlServer.Dts.Runtime;
namespace ExtendedProperties_Testing
{
class Program
{
static void Main(string[] args)
{
// The package is one of the SSIS Samples.
string mySample = @"C:\Program Files\Microsoft SQL Server\90\Tools\Samples\1033\DataTransformationServices\Package Samples\CalculatedColumns Sample\CalculatedColumns\CalculatedColumns.dtsx";
// Create the Application, and load the sample.
Application app = new Application();
Package pkg = app.LoadPackage(mySample, null);
// Get the Extended properties collection from the package.
ExtendedProperties myExtProps = pkg.ExtendedProperties;
//Create the Enumerator.
ExtendedPropertyEnumerator myEnumerator = myExtProps.GetEnumerator();
Console.WriteLine("The collection contains the following values:");
int i = 0;
ExtendedProperty myExtProp;
while ((myEnumerator.MoveNext()) && (myEnumerator.Current != null))
{
myExtProp = (ExtendedProperty)myEnumerator.Current;
Console.WriteLine("[{0}] {1}, {2}", i++, myExtProp.ID, myExtProp.DataType);
Console.WriteLine("------------------------------");
}
// Reset puts the index pointer before the beginning.
// Do not retrieve from the collection until MoveNext is called.
myEnumerator.Reset();
myEnumerator.MoveNext();
// Now that the enumerator has been reset, and moved to the
// first item in the collection, show the first item.
myExtProp = (ExtendedProperty)myEnumerator.Current;
Console.WriteLine("The first item in the enumerator after Reset:");
Console.WriteLine("{0}, {1}", myExtProp.ID, myExtProp.DataType);
Console.WriteLine();
}
}
}
Imports System
Imports System.Collections.Generic
Imports System.Text
Imports Microsoft.SqlServer.Dts.Runtime
Namespace ExtendedProperties_Testing
Class Program
Shared Sub Main(ByVal args() As String)
' The package is one of the SSIS Samples.
Dim mySample As String = "C:\Program Files\Microsoft SQL Server\90\Tools\Samples\1033\DataTransformationServices\Package Samples\CalculatedColumns Sample\CalculatedColumns\CalculatedColumns.dtsx"
' Create the Application, and load the sample.
Dim app As Application = New Application()
Dim pkg As Package = app.LoadPackage(mySample,Nothing)
' Get the Extended properties collection from the package.
Dim myExtProps As ExtendedProperties = pkg.ExtendedProperties
'Create the Enumerator.
Dim myEnumerator As ExtendedPropertyEnumerator = myExtProps.GetEnumerator()
Console.WriteLine("The collection contains the following values:")
Dim i As Integer = 0
Dim myExtProp As ExtendedProperty
While (myEnumerator.MoveNext()) &&(myEnumerator.Current <> Nothing)
myExtProp = CType(myEnumerator.Current, ExtendedProperty)
Console.WriteLine("[{0}] {1}, {2}",i = Console.WriteLine("[{0}] {1}, {2}",i + 1
Console.WriteLine("------------------------------")
End While
' Reset puts the index pointer before the beginning.
' Do not retrieve from the collection until MoveNext is called.
myEnumerator.Reset()
myEnumerator.MoveNext()
' Now that the enumerator has been reset, and moved to the
' first item in the collection, show the first item.
myExtProp = CType(myEnumerator.Current, ExtendedProperty)
Console.WriteLine("The first item in the enumerator after Reset:")
Console.WriteLine("{0}, {1}", myExtProp.ID, myExtProp.DataType)
Console.WriteLine()
End Sub
End Class
End Namespace
Sample Output:
The collection contains the following values:
[0] {F3B7314E-DB1E-4CCA-A856-2E617A1B3265}, String
------------------------------
[1] {AA947F2D-C3B3-420F-B39E-4B7C77DAAFC0}, String
------------------------------
[2] {AB2CCC33-3090-4C36-B444-5B50BB481324}, String
------------------------------
[3] {FE85601C-4ECC-41D4-BEAA-1318DDF7EE2A}, String
------------------------------
[4] {4D1641B9-94EF-4144-9820-1B30ABD2214F}, String
------------------------------
[5] {4E76A01C-BFF8-462D-AAB0-FB48B3EEAE00}, String
------------------------------
[6] {A56842E2-11C1-487E-B670-33F25B534146}, String
------------------------------
The first item in the enumerator after Reset:
{F3B7314E-DB1E-4CCA-A856-2E617A1B3265}, String
Seguridad para subprocesos
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.
Plataformas
Plataformas de desarrollo
Para obtener una lista de las plataformas compatibles, vea Requisitos de hardware y software para instalar SQL Server 2005.
Plataformas de destino
Para obtener una lista de las plataformas compatibles, vea Requisitos de hardware y software para instalar SQL Server 2005.
Vea también
Referencia
ExtendedPropertyEnumerator Class
ExtendedPropertyEnumerator Members
Microsoft.SqlServer.Dts.Runtime Namespace