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DtsEnumerator-Klasse

Defines an abstract base class that implements the IEnumerator methods.

Vererbungshierarchie

System.Object
  Microsoft.SqlServer.Dts.Runtime.DtsEnumerator
    Mehr…

Namespace:  Microsoft.SqlServer.Dts.Runtime
Assembly:  Microsoft.SqlServer.ManagedDTS (in Microsoft.SqlServer.ManagedDTS.dll)

Syntax

'Declaration
Public MustInherit Class DtsEnumerator _
    Implements IEnumerator
'Usage
Dim instance As DtsEnumerator
public abstract class DtsEnumerator : IEnumerator
public ref class DtsEnumerator abstract : IEnumerator
[<AbstractClassAttribute>]
type DtsEnumerator =  
    class 
        interface IEnumerator 
    end
public abstract class DtsEnumerator implements IEnumerator

Der DtsEnumerator-Typ macht folgende Elemente verfügbar.

Konstruktoren

  Name Beschreibung
Öffentliche Methode DtsEnumerator Initializes a new instance of the DtsEnumerator class.

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Eigenschaften

  Name Beschreibung
Öffentliche Eigenschaft Current Gets the current element in the collection.

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Methoden

  Name Beschreibung
Öffentliche Methode Equals (Geerbt von Object.)
Geschützte Methode Finalize (Geerbt von Object.)
Öffentliche Methode GetHashCode (Geerbt von Object.)
Öffentliche Methode GetType (Geerbt von Object.)
Geschützte Methode MemberwiseClone (Geerbt von Object.)
Öffentliche Methode MoveNext Advances the enumerator to the next element of the collection.
Öffentliche Methode Reset Sets the enumerator to its initial position, which is before the first element in the collection.
Öffentliche Methode ToString (Geerbt von Object.)

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Hinweise

DtsEnumerator is the base interface for all enumerators. The DtsEnumerator allows only reading of the data in the collection and is not used to modify the underlying collection.

Initially, the enumerator is positioned before the first element in the collection. Reset also brings the enumerator back to this position. At this position, calling Current throws an exception. Therefore, you must call MoveNext to advance the enumerator to the first element of the collection before reading the value of Current.

Current returns the same object until either MoveNext or Reset is called. MoveNext sets Current to the next element.

After the end of the collection is passed, the enumerator is positioned after the last element in the collection, and calling MoveNext returns false. If the last call to MoveNext returned false, calling Current throws an exception. To set Current to the first element of the collection again, you can call Reset followed by MoveNext.

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 irrecoverably invalidated and the next call to MoveNext or Reset throws an InvalidOperationException. If the collection is modified between MoveNext and Current, Current will return the element that it is set to, even if the enumerator is already invalidated.

The enumerator does not have exclusive access to the collection; therefore, enumerating through a collection is not a thread-safe procedure. Even when a collection is synchronized, other threads could still modify the collection, which causes the enumerator to throw an exception. To guarantee thread safety during enumeration, you can lock the collection during the entire enumeration or catch the exceptions that result from changes made by other threads.

Beispiele

The following code example adds a task to a package then runs the package. The warnings collection is shown by creating a WarningEnumerator, which inherits from this DtsEnumerator class, and displays each warning description.

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

namespace Microsoft.SqlServer.SSIS.Samples
{
    class Program
    {
        static void Main(string[] args)
        {
            Package package = new Package();
            Console.WriteLine("Package warnings count before running: {0}", package.Warnings.Count);

            TaskHost taskH2 = (TaskHost)package.Executables.Add("STOCK:SendMailTask");
            taskH2.FailPackageOnFailure = false;
            taskH2.FailParentOnFailure = false;
            Console.WriteLine("SendMailTask: {0}", taskH2.ID);
 
            // Test that warnings were successfully added to the collection.
            package.MaximumErrorCount = 100;
            package.FailPackageOnFailure = false;
            package.FailParentOnFailure = false;
            package.DelayValidation = true;
            package.Execute();

            Console.WriteLine("Package warnings count after running the package: {0}", package.Warnings.Count);

            // Create the enumerator.
            WarningEnumerator myEnumerator = package.Warnings.GetEnumerator();
            Console.WriteLine("The collection contains the following values:");
            int i = 0;
            while ((myEnumerator.MoveNext()) && (myEnumerator.Current != null))
                Console.WriteLine("[{0}] {1}", i++, myEnumerator.Current.Description);
        }
    }
}
Imports System
Imports System.Collections.Generic
Imports System.Text
Imports Microsoft.SqlServer.Dts.Runtime
Imports Microsoft.SqlServer.Dts.Tasks.ExecuteSQLTask
 
Namespace Microsoft.SqlServer.SSIS.Samples
    Class Program
        Shared  Sub Main(ByVal args() As String)
            Dim package As Package =  New Package() 
            Console.WriteLine("Package warnings count before running: {0}", package.Warnings.Count)
 
            Dim taskH2 As TaskHost = CType(package.Executables.Add("STOCK:SendMailTask"), TaskHost)
            taskH2.FailPackageOnFailure = False
            taskH2.FailParentOnFailure = False
            Console.WriteLine("SendMailTask: {0}", taskH2.ID)
 
            ' Test that warnings were successfully added to the collection.
            package.MaximumErrorCount = 100
            package.FailPackageOnFailure = False
            package.FailParentOnFailure = False
            package.DelayValidation = True
            package.Execute()
 
            Console.WriteLine("Package warnings count after running the package: {0}", package.Warnings.Count)
 
            ' Create the enumerator.
            Dim myEnumerator As WarningEnumerator =  package.Warnings.GetEnumerator() 
            Console.WriteLine("The collection contains the following values:")
            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:

Package warnings count before running: 0

SendMailTask: {34CAEFF9-64BF-401D-B646-C88B705DB971}

Package warnings count after running the package: 2

The collection contains the following values:

[0] The address in the From line is not formed correctly. It is missing an @ or it is not valid.

[1] Subject is empty

Threadsicherheit

Alle öffentlichen static (Shared in Visual Basic)-Elemente dieses Typs sind Threadsicher. Für Instanzelemente wird die Threadsicherheit nicht gewährleistet.

Siehe auch

Verweis

Microsoft.SqlServer.Dts.Runtime-Namespace

Vererbungshierarchie

System.Object
  Microsoft.SqlServer.Dts.Runtime.DtsEnumerator
    Microsoft.SqlServer.Dts.Runtime.BreakpointTargetEnumerator
    Microsoft.SqlServer.Dts.Runtime.ConfigurationEnumerator
    Microsoft.SqlServer.Dts.Runtime.ConnectionEnumerator
    Microsoft.SqlServer.Dts.Runtime.ConnectionInfoEnumerator
    Microsoft.SqlServer.Dts.Runtime.DBProviderInfoEnumerator
    Microsoft.SqlServer.Dts.Runtime.DtsEventHandlerEnumerator
    Microsoft.SqlServer.Dts.Runtime.ErrorEnumerator
    Microsoft.SqlServer.Dts.Runtime.EventInfoEnumerator
    Microsoft.SqlServer.Dts.Runtime.ExecutableEnumerator
    Microsoft.SqlServer.Dts.Runtime.ExtendedPropertyEnumerator
    Microsoft.SqlServer.Dts.Runtime.ForEachEnumeratorInfosEnumerator
    Microsoft.SqlServer.Dts.Runtime.ForEachVariableMappingEnumerator
    Microsoft.SqlServer.Dts.Runtime.LogEntryInfoEnumerator
    Microsoft.SqlServer.Dts.Runtime.LogProviderEnumerator
    Microsoft.SqlServer.Dts.Runtime.LogProviderInfoEnumerator
    Microsoft.SqlServer.Dts.Runtime.PackageInfoEnumerator
    Microsoft.SqlServer.Dts.Runtime.PackageParameterEnumerator
    Microsoft.SqlServer.Dts.Runtime.PipelineComponentInfoEnumerator
    Microsoft.SqlServer.Dts.Runtime.PrecedenceConstraintEnumerator
    Microsoft.SqlServer.Dts.Runtime.PropertyEnumerator
    Microsoft.SqlServer.Dts.Runtime.RunningPackagesEnumerator
    Microsoft.SqlServer.Dts.Runtime.TaskInfoEnumerator
    Microsoft.SqlServer.Dts.Runtime.VariableEnumerator
    Microsoft.SqlServer.Dts.Runtime.WarningEnumerator