public shared function GetFile (fileURL as String , resolver as XmlResolver) as Object
 
  '  Generate the default PermissionSet using the file URL.
  Dim evidence as Evidence = XmlSecureResolver.CreateEvidenceForUrl(fileURL)
  Dim myPermissions as PermissionSet = SecurityManager.ResolvePolicy(evidence)

  '  Modify the PermissionSet to only allow access to http://www.contoso.com.
  '  Create a WebPermission that only allows access to http://www.contoso.com.
  Dim myWebPermission as WebPermission = new WebPermission(NetworkAccess.Connect, "http://www.contoso.com")
  '  Replace the existing WebPermission in myPermissions with the updated WebPermission.
  myPermissions.SetPermission(myWebPermission)

  '  Use the modified PermissionSet to construct the XmlSecureResolver.
  Dim sResolver as XmlSecureResolver = new XmlSecureResolver(resolver, myPermissions)

  '  Get the object.
  Dim fullUri as Uri = sResolver.ResolveUri(nothing, fileURL)
  return sResolver.GetEntity(fullUri, nothing, nothing)
end function

Dim myEvidence As Evidence = Me.GetType().Assembly.Evidence
Dim myResolver As XmlSecureResolver
myResolver = New XmlSecureResolver(New XmlUrlResolver(), myEvidence)