AsnEncodedDataEnumerator.MoveNext Method ()
Assembly: System (in System.dll)
The collection was modified after the enumerator was created.
After an enumerator is created, it is positioned before the first element of the collection, and the first call to themethod moves the enumerator over the first element of the collection. Subsequent calls to advance the enumerator past subsequent elements.
After the end of the collection is passed, calls toreturn false.
An enumerator is valid as long as the collection remains unchanged. If changes are made to the collection, such as adding, modifying, or deleting elements, the enumerator becomes invalid and the next call to InvalidOperationException.can throw an
The following code example shows how to use the AsnEncodedDataEnumerator 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. 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 'Main End Class 'AsnEncodedDataSample
Available since 2.0