Sdílet prostřednictvím


LogProviderEnumerator.Current Property

Definition

Gets the current LogProvider element in the collection.

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

Property Value

The current LogProvider element in the collection.

Examples

The following code example adds and removes log providers for the package, in addition to creating an enumerator by using the GetEnumerator method, 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 Microsoft.SqlServer.SSIS.Samples  
{  
    class Program  
    {  
        static void Main(string[] args)  
        {  
            Package pkg = new Package();  
            // Make several log providers available to the package.  
            LogProvider log1 = pkg.LogProviders.Add("DTS.LogProviderEventLog.1");  
            LogProvider log2 = pkg.LogProviders.Add("DTS.LogProviderSQLProfiler.1");  
            LogProvider log3 = pkg.LogProviders.Add("DTS.LogProviderTextFile.1");  
            LogProvider log4 = pkg.LogProviders.Add("DTS.LogProviderTextFile.1");  
            // Show the log providers available to the package.  
            Console.WriteLine("Log providers available in the Package:");  
            LogProviders logs = pkg.LogProviders;  
            foreach (LogProvider lp in logs)  
                Console.WriteLine(lp.CreationName);  

            // Pick a log provider for the package.  
            pkg.LoggingOptions.SelectedLogProviders.Add(log4);  
            pkg.LoggingOptions.SelectedLogProviders.Add(log1);  
            SelectedLogProviders provs = pkg.LoggingOptions.SelectedLogProviders;  
            Console.WriteLine();  
            Console.WriteLine("Selected Log Providers for Package: {0}", provs.Count);  

            foreach (LogProvider lp in provs)  
                Console.WriteLine(lp.CreationName);  

            pkg.LoggingOptions.SelectedLogProviders.Remove(0);  
            Console.WriteLine();  
            Console.WriteLine("Count after one has been removed {0}", provs.Count);  

            // Test both the indexer and Contains method.  
            if (logs.Contains(0))  
                Console.WriteLine("Index zero in collection contains:  {0}", logs[0].CreationName);  
            else  
                throw new Exception();  

            // Show the use of the GetEnumerator.  
            LogProviderEnumerator myEnum = pkg.LogProviders.GetEnumerator();  
            Console.WriteLine("The collection contains the following values:");  
            while ((myEnum.MoveNext()) && (myEnum.Current != null))  
                Console.WriteLine("{0}", myEnum.Current.Name);  
        }  
    }  
}  
Imports System  
Imports System.Collections.Generic  
Imports System.Text  
Imports Microsoft.SqlServer.Dts.Runtime  

Namespace Microsoft.SqlServer.SSIS.Samples  
    Class Program  
        Shared  Sub Main(ByVal args() As String)  
            Dim pkg As Package =  New Package()   
            ' Make several log providers available to the package.  
            Dim log1 As LogProvider =  pkg.LogProviders.Add("DTS.LogProviderEventLog.1")   
            Dim log2 As LogProvider =  pkg.LogProviders.Add("DTS.LogProviderSQLProfiler.1")   
            Dim log3 As LogProvider =  pkg.LogProviders.Add("DTS.LogProviderTextFile.1")   
            Dim log4 As LogProvider =  pkg.LogProviders.Add("DTS.LogProviderTextFile.1")   
            ' Show the log providers available to the package.  
            Console.WriteLine("Log providers available in the Package:")  
            Dim logs As LogProviders =  pkg.LogProviders   
            Dim lp As LogProvider  
            For Each lp In logs  
                Console.WriteLine(lp.CreationName)  
            Next  

            ' Pick a log provider for the package.  
            pkg.LoggingOptions.SelectedLogProviders.Add(log4)  
            pkg.LoggingOptions.SelectedLogProviders.Add(log1)  
            Dim provs As SelectedLogProviders =  pkg.LoggingOptions.SelectedLogProviders   
            Console.WriteLine()  
            Console.WriteLine("Selected Log Providers for Package: {0}", provs.Count)  

            Dim lp As LogProvider  
            For Each lp In provs  
                Console.WriteLine(lp.CreationName)  
            Next  

            pkg.LoggingOptions.SelectedLogProviders.Remove(0)  
            Console.WriteLine()  
            Console.WriteLine("Count after one has been removed {0}", provs.Count)  

            ' Test both the indexer and Contains method.  
            If logs.Contains(0) Then  
                Console.WriteLine("Index zero in collection contains:  {0}", logs(0).CreationName)  
            Else   
                Throw New Exception()  
            End If  

            ' Show the use of the GetEnumerator.  
            Dim myEnum As LogProviderEnumerator =  pkg.LogProviders.GetEnumerator()   
            Console.WriteLine("The collection contains the following values:")  
            While (myEnum.MoveNext()) &&(myEnum.Current <> Nothing)  
                Console.WriteLine("{0}", myEnum.Current.Name)  
            End While  
        End Sub  
    End Class  
End Namespace  

Sample Output:

Log providers available in the Package:

DTS.LogProviderTextFile.1

DTS.LogProviderSQLProfiler.1

DTS.LogProviderEventLog.1

DTS.LogProviderTextFile.1

Selected Log Providers for Package: 2

DTS.LogProviderTextFile.1

DTS.LogProviderEventLog.1

Count after one has been removed 1

Index zero in collection contains: DTS.LogProviderTextFile.1

The collection contains the following values:

{9A4FD6D3-7DE2-43AD-8B02-CE9B02E7504B}

{AB1C156F-8018-4063-A1A5-48E122CE6FFD}

{B8E93B36-36FE-4E65-9814-9752915E9E15}

{E586A867-86EC-4901-8F5A-C945D4469C46}

Remarks

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.

Applies to