public void ReadFrom(XmlDictionaryReader reader, TransformFactory transformFactory, DictionaryManager dictionaryManager) { reader.MoveToStartElement(dictionaryManager.XmlSignatureDictionary.Transforms, dictionaryManager.XmlSignatureDictionary.Namespace); this.prefix = reader.Prefix; reader.Read(); while (reader.IsStartElement(dictionaryManager.XmlSignatureDictionary.Transform, dictionaryManager.XmlSignatureDictionary.Namespace)) { string attribute = reader.GetAttribute(dictionaryManager.XmlSignatureDictionary.Algorithm, null); Transform transform = transformFactory.CreateTransform(attribute); transform.ReadFrom(reader, dictionaryManager); this.Add(transform); } reader.MoveToContent(); reader.ReadEndElement(); if (this.TransformCount == 0) { throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new CryptographicException(System.IdentityModel.SR.GetString("AtLeastOneTransformRequired"))); } }