CodeAccessPermission.FromXml(SecurityElement) Metode

Definisi

Ruang nama:

System.Security

Rakitan:

System.Security.Permissions.dll

Saat ditimpa di kelas turunan, merekonstruksi objek keamanan dengan status tertentu dari pengodean XML.

public:
 abstract void FromXml(System::Security::SecurityElement ^ elem);

public abstract void FromXml (System.Security.SecurityElement elem);

abstract member FromXml : System.Security.SecurityElement -> unit

Public MustOverride Sub FromXml (elem As SecurityElement)

Parameter

elem

SecurityElement

Pengodean XML yang digunakan untuk merekonstruksi objek keamanan.

Penerapan

FromXml(SecurityElement)

Pengecualian

ArgumentNullException

Parameternya elem adalah null.

ArgumentException

Parameter elem tidak berisi pengodean XML untuk instans dengan jenis yang sama dengan instans saat ini.

-atau-

Nomor elem versi parameter tidak didukung.

Contoh

Contoh kode berikut menunjukkan penimpaan FromXml metode . Contoh kode ini adalah bagian dari contoh yang lebih besar yang disediakan untuk CodeAccessPermission kelas .

public:
   virtual void FromXml( SecurityElement^ e ) override
   {
      // The following code for unrestricted permission is only included as an example for
      // permissions that allow the unrestricted state. It is of no value for this permission.
      String^ elUnrestricted = e->Attribute("Unrestricted");
      if ( nullptr != elUnrestricted )
      {
         m_Unrestricted = Boolean::Parse( elUnrestricted );
         return;
      }

      String^ elName = e->Attribute("Name");
      m_Name = elName == nullptr ? nullptr : elName;
   }

public override void FromXml(SecurityElement e)
 {
     // The following code for unrestricted permission is only included as an example for
     // permissions that allow the unrestricted state. It is of no value for this permission.
     String elUnrestricted = e.Attribute("Unrestricted");
     if (null != elUnrestricted)
     {
         m_Unrestricted = bool.Parse(elUnrestricted);
         return;
     }

     String elName = e.Attribute( "Name" );
     m_Name = elName == null ? null : elName;
 }

Public Overrides Sub FromXml(ByVal e As SecurityElement)
    ' The following code for unrestricted permission is only included as an example for
    ' permissions that allow the unrestricted state. It is of no value for this permission.
    Dim elUnrestricted As String = e.Attribute("Unrestricted")
    If Nothing <> elUnrestricted Then
        m_Unrestricted = Boolean.Parse(elUnrestricted)
        Return
    End If

    Dim elName As String = e.Attribute("Name")
    m_name = IIf(elName Is Nothing, Nothing, elName)
End Sub

Keterangan

Kode kustom yang memperluas objek keamanan perlu menerapkan ToXml metode dan FromXml untuk membuat objek dapat dikodekan keamanan.

Catatan Bagi Implementer

Anda harus mengambil alih metode ini di kelas turunan.