缓存数据处理（使用xml文件）

 使用在本地生成xml文件的方法，生成缓存，减少与数据库的交互，提高性能。XmlSerializer可以进行序列化和反序列化

public static CaseTypeEntity[] GetCaseTypeEntityCollection()
        {
            if (_IsReLoad || (_CaseTypeEntity == null))
            {
                if (File.Exists(MC_CaseTypeEntity_File))
                {
                    FileStream stream = new FileStream(MC_CaseTypeEntity_File, FileMode.Open);
                    XmlSerializer serializer = new XmlSerializer(typeof(CaseTypeEntity[]));
                    _CaseTypeEntity = (CaseTypeEntity[])serializer.Deserialize(stream);
                    stream.Close();
                }
                else
                {
                    try
                    {
                        _CaseTypeEntity = WebServicesProxy.GetCaseTypeEntityCollection();
                        FileStream stream2 = new FileStream(MC_CaseTypeEntity_File, FileMode.Create, FileAccess.ReadWrite);
                        new XmlSerializer(typeof(CaseTypeEntity[])).Serialize((Stream)stream2, _CaseTypeEntity);
                        stream2.Close();
                    }
                    catch (Exception)
                    {
                        return null;
                    }
                }
            }
            return _CaseTypeEntity;
        }