AsnEncodedDataCollection.Count Property


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Gets the number of AsnEncodedData objects in a collection.

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

Public ReadOnly Property Count As Integer

Property Value

Type: System.Int32

The number of AsnEncodedData objects.

Use this property to determine how many AsnEncodedData objects the collection contains.

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

Imports System
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.
         ' 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()

            ' 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

               ' Add the AsnEncodedData object to the AsnEncodedDataCollection object.
            Next extension
         Next i
	 msg = "Number of AsnEncodedData items in the collection: " & asncoll.Count

         '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.
         ' Write out AsnEncodedData in the collection.
	 msg = "First AsnEncodedData in the collection: " & asne.Current.Format(True)

	 msg = "Second AsnEncodedData in the collection: " & asne.Current.Format(True)

         'Return index in the collection to the beginning.
         MsgBox("Information could not be written out for this certificate.")
      End Try
   End Sub 'Main
End Class 'AsnEncodedDataSample

.NET Framework
Available since 2.0
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