AsnEncodedDataEnumerator.Current Vlastnost

Definice

Obor názvů:

System.Security.Cryptography

Sestavení:

System.Security.Cryptography.Encoding.dll

Sestavení:

System.Security.Cryptography.dll

Sestavení:

System.dll

Sestavení:

netstandard.dll

Získá aktuální AsnEncodedData objekt v objektu AsnEncodedDataCollection .

public:
 property System::Security::Cryptography::AsnEncodedData ^ Current { System::Security::Cryptography::AsnEncodedData ^ get(); };

public System.Security.Cryptography.AsnEncodedData Current { get; }

member this.Current : System.Security.Cryptography.AsnEncodedData

Public ReadOnly Property Current As AsnEncodedData

Hodnota vlastnosti

AsnEncodedData

Aktuální AsnEncodedData objekt v kolekci.

Příklady

Následující příklad kódu ukazuje, jak používat AsnEncodedDataEnumerator třídu.

#using <System.dll>
#using <System.Security.dll>

using namespace System;
using namespace System::Security::Cryptography;
using namespace System::Security::Cryptography::X509Certificates;

int main()
{
   
   //The following example demonstrates the usage of the AsnEncodedData classes.
   // Asn encoded data is read from the extensions of an X509 certificate.
   try
   {
      
      // Open the certificate store.
      X509Store^ store = gcnew X509Store( L"MY",StoreLocation::CurrentUser );
      store->Open( static_cast<OpenFlags>(OpenFlags::ReadOnly | OpenFlags::OpenExistingOnly) );
      X509Certificate2Collection^ collection = dynamic_cast<X509Certificate2Collection^>(store->Certificates);
      X509Certificate2Collection^ fcollection = dynamic_cast<X509Certificate2Collection^>(collection->Find( X509FindType::FindByTimeValid, DateTime::Now, false ));
      
      // Select one or more certificates to display extensions information.
      X509Certificate2Collection^ scollection = X509Certificate2UI::SelectFromCollection(fcollection, L"Certificate Select",L"Select certificates from the following list to get extension information on that certificate",X509SelectionFlag::MultiSelection);
      
      // Create a new AsnEncodedDataCollection object.
      AsnEncodedDataCollection^ asncoll = gcnew AsnEncodedDataCollection;
      for ( int i = 0; i < scollection->Count; i++ )
      {
         
         // Display certificate information.
         Console::ForegroundColor = ConsoleColor::Red;
         Console::WriteLine( L"Certificate name: {0}", scollection[i]->GetName() );
         Console::ResetColor();
         
         // Display extensions information.
         System::Collections::IEnumerator^ myEnum = scollection[i]->Extensions->GetEnumerator();
         while ( myEnum->MoveNext() )
         {
            X509Extension^ extension = safe_cast<X509Extension ^>(myEnum->Current);
            
            // Create an AsnEncodedData object using the extensions information.
            AsnEncodedData^ asndata = gcnew AsnEncodedData( extension->Oid,extension->RawData );
            Console::ForegroundColor = ConsoleColor::Green;
            Console::WriteLine( L"Extension type: {0}", extension->Oid->FriendlyName );
            Console::WriteLine( L"Oid value: {0}", asndata->Oid->Value );
            Console::WriteLine( L"Raw data length: {0} {1}", asndata->RawData->Length, Environment::NewLine );
            Console::ResetColor();
            Console::WriteLine( asndata->Format(true) );
            Console::WriteLine( Environment::NewLine );
            
            // Add the AsnEncodedData object to the AsnEncodedDataCollection object.
            asncoll->Add( asndata );
         }

         Console::WriteLine( Environment::NewLine );

      }
      Console::ForegroundColor = ConsoleColor::Red;
      Console::WriteLine( L"Number of AsnEncodedData items in the collection: {0} {1}", asncoll->Count, Environment::NewLine );
      Console::ResetColor();
      store->Close();
      
      //Create an enumerator for moving through the collection.
      AsnEncodedDataEnumerator^ asne = asncoll->GetEnumerator();
      
      //You must execute a MoveNext() to get to the first item in the collection.
      asne->MoveNext();
      
      // Write out AsnEncodedData in the collection.
      Console::ForegroundColor = ConsoleColor::Blue;
      Console::WriteLine( L"First AsnEncodedData in the collection: {0}", asne->Current->Format(true) );
      Console::ResetColor();
      asne->MoveNext();
      Console::ForegroundColor = ConsoleColor::DarkBlue;
      Console::WriteLine( L"Second AsnEncodedData in the collection: {0}", asne->Current->Format(true) );
      Console::ResetColor();
      
      //Return index in the collection to the beginning.
      asne->Reset();
   }
   catch ( CryptographicException^ ) 
   {
      Console::WriteLine( L"Information could not be written out for this certificate." );
   }

   return 1;
}

using System;
using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;

class AsnEncodedDataSample
{
    static void Main()
    {		
        //The following example demonstrates the usage the AsnEncodedData classes.
        // Asn encoded data is read from the extensions of an X509 certificate.
        try
        {
            // Open the certificate store.
            X509Store store = new X509Store("MY", StoreLocation.CurrentUser);
            store.Open(OpenFlags.ReadOnly | OpenFlags.OpenExistingOnly);
            X509Certificate2Collection collection = (X509Certificate2Collection)store.Certificates;
            X509Certificate2Collection fcollection = (X509Certificate2Collection)collection.Find(X509FindType.FindByTimeValid, DateTime.Now, false);
            // Select one or more certificates to display extensions information.
            X509Certificate2Collection scollection = X509Certificate2UI.SelectFromCollection(fcollection, "Certificate Select", "Select certificates from the following list to get extension information on that certificate", X509SelectionFlag.MultiSelection);

            // Create a new AsnEncodedDataCollection object.
            AsnEncodedDataCollection asncoll = new AsnEncodedDataCollection();
            for (int i = 0; i < scollection.Count; i++)
            {
                // Display certificate information.
                Console.ForegroundColor = ConsoleColor.Red;
                Console.WriteLine("Certificate name: {0}", scollection[i].GetName());
                Console.ResetColor();
                // Display extensions information.
                foreach (X509Extension extension in scollection[i].Extensions)
                {
                    // Create an AsnEncodedData object using the extensions information.
                    AsnEncodedData asndata = new AsnEncodedData(extension.Oid, extension.RawData);
                    Console.ForegroundColor = ConsoleColor.Green;
                    Console.WriteLine("Extension type: {0}", extension.Oid.FriendlyName);
                    Console.WriteLine("Oid value: {0}",asndata.Oid.Value);
                    Console.WriteLine("Raw data length: {0} {1}", asndata.RawData.Length, Environment.NewLine);
                    Console.ResetColor();
                    Console.WriteLine(asndata.Format(true));
                    Console.WriteLine(Environment.NewLine);
                    // Add the AsnEncodedData object to the AsnEncodedDataCollection object.
                    asncoll.Add(asndata);
                }
                Console.WriteLine(Environment.NewLine);
            }
            Console.ForegroundColor = ConsoleColor.Red;
            Console.WriteLine("Number of AsnEncodedData items in the collection: {0} {1}", asncoll.Count, Environment.NewLine);
            Console.ResetColor();

            store.Close();
            //Create an enumerator for moving through the collection.
            AsnEncodedDataEnumerator asne = asncoll.GetEnumerator();
            //You must execute a MoveNext() to get to the first item in the collection.
            asne.MoveNext();
            // Write out AsnEncodedData in the collection.
            Console.ForegroundColor = ConsoleColor.Blue;
            Console.WriteLine("First AsnEncodedData in the collection: {0}", asne.Current.Format(true));
            Console.ResetColor();

            asne.MoveNext();
            Console.ForegroundColor = ConsoleColor.DarkBlue;
            Console.WriteLine("Second AsnEncodedData in the collection: {0}", asne.Current.Format(true));
            Console.ResetColor();
            //Return index in the collection to the beginning.
            asne.Reset();
        }
        catch (CryptographicException)
        {
            Console.WriteLine("Information could not be written out for this certificate.");
        }
    }
}

Imports System.Security.Cryptography
Imports System.Security.Cryptography.X509Certificates



Class AsnEncodedDataSample
   Shared msg As String
   Shared Sub Main()
      'The following example demonstrates the usage the AsnEncodedData classes.
      ' Asn encoded data is read from the extensions of an X509 certificate.
      Try
         ' Open the certificate store.
         Dim store As New X509Store("MY", StoreLocation.CurrentUser)
         store.Open((OpenFlags.ReadOnly Or OpenFlags.OpenExistingOnly))
         Dim collection As X509Certificate2Collection = CType(store.Certificates, X509Certificate2Collection)
         Dim fcollection As X509Certificate2Collection = CType(collection.Find(X509FindType.FindByTimeValid, DateTime.Now, False), X509Certificate2Collection)
         ' Select one or more certificates to display extensions information.
         Dim scollection As X509Certificate2Collection = X509Certificate2UI.SelectFromCollection(fcollection, "Certificate Select", "Select certificates from the following list to get extension information on that certificate", X509SelectionFlag.MultiSelection)
         
         ' Create a new AsnEncodedDataCollection object.
         Dim asncoll As New AsnEncodedDataCollection()
         Dim i As Integer
         For i = 0 To scollection.Count - 1
            ' Display certificate information.
        msg = "Certificate name: "& scollection(i).GetName()
            MsgBox(msg)

            ' Display extensions information.
            Dim extension As X509Extension
            For Each extension In  scollection(i).Extensions
               ' Create an AsnEncodedData object using the extensions information.
               Dim asndata As New AsnEncodedData(extension.Oid, extension.RawData)
           msg = "Extension type: " & extension.Oid.FriendlyName & Environment.NewLine & "Oid value: " & asndata.Oid.Value _
        & Environment.NewLine & "Raw data length: " & asndata.RawData.Length & Environment.NewLine _
        & asndata.Format(True) & Environment.NewLine
               MsgBox(msg)
        
               ' Add the AsnEncodedData object to the AsnEncodedDataCollection object.
               asncoll.Add(asndata)
            Next extension
         Next i
     msg = "Number of AsnEncodedData items in the collection: " & asncoll.Count
         MsgBox(msg)         
         store.Close()

         'Create an enumerator for moving through the collection.
         Dim asne As AsnEncodedDataEnumerator = asncoll.GetEnumerator()
         'You must execute a MoveNext() to get to the first item in the collection.
         asne.MoveNext()
         ' Write out AsnEncodedData in the collection.
     msg = "First AsnEncodedData in the collection: " & asne.Current.Format(True)
     MsgBox(msg)
    
         
         asne.MoveNext()
     msg = "Second AsnEncodedData in the collection: " & asne.Current.Format(True)
     MsgBox(msg)
        
         'Return index in the collection to the beginning.
         asne.Reset()
      Catch 
         MsgBox("Information could not be written out for this certificate.")
      End Try
   End Sub
End Class

Poznámky

Po vytvoření enumerátoru MoveNext je nutné metodu volat, aby se enumerátor před přečtením hodnoty Current vlastnosti převolal na první prvek kolekce, Current jinak vrátí null nebo vyvolá výjimku.

Current vrátí null nebo vyvolá výjimku, pokud se poslední volání MoveNext vrátí false, což znamená, že konec kolekce byl dosažen.

Current nepřesune pozici enumerátoru a po sobě jdoucí volání, která Current vrátí stejný objekt, dokud MoveNext se nevolá.