AsnEncodedDataEnumerator.Current 属性

参考

定义

命名空间:: System.Security.Cryptography

程序集:: System.Security.Cryptography.Encoding.dll

程序集:: System.Security.Cryptography.dll

程序集:: System.dll

程序集:: netstandard.dll

重要

一些信息与预发行产品相关，相应产品在发行之前可能会进行重大修改。对于此处提供的信息，Microsoft 不作任何明示或暗示的担保。

在 AsnEncodedData 对象中获取当前 AsnEncodedDataCollection 对象。

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

属性值

AsnEncodedData

集合中的当前 AsnEncodedData 对象。

示例

下面的代码示例演示如何使用 AsnEncodedDataEnumerator 类。

#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

注解

创建枚举器后， MoveNext 必须调用该方法才能在读取属性的值 Current 之前将枚举器提升到集合的第一个元素;否则返回 Current null 或引发异常。

Current如果最后一次调用返回MoveNextfalse，则返回null或引发异常，这表示已到达集合的末尾。

Current 不会移动枚举器的位置，并且连续调用以 Current 返回相同的对象，直到 MoveNext 调用为止。

适用于

AsnEncodedDataEnumerator.Current 属性

定义

属性值

示例

注解

适用于

其他资源