AsnEncodedDataCollection.Item Property (Int32)

 
System_CAPS_noteNote

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Gets an AsnEncodedData object from the AsnEncodedDataCollection object.

Namespace:   System.Security.Cryptography
Assembly:  System (in System.dll)

public AsnEncodedData this[
	int index
] { get; }

Parameters

index
Type: System.Int32

The location in the collection.

Use this method to retrieve an AsnEncodedData object from an AsnEncodedDataCollection object, if you know its location.

The following code example shows how to use the AsnEncodedDataCollection class.

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.");
		}
	}
}

.NET Framework
Available since 2.0
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