webserviceSoapExtensionAttribute和SoapExtension

SoapExtension和SoapExtensionAttribute两个类用于控制webservice序列化和反序列化的一般过程，可对webservice进行压缩和日志等功能进行控制，关于对整个webservice传输的wsdl进行压缩的功能我没做过，不过下周有时间应该会先试试

SoapExtensionAttribute类：

public class ExtensionAttribute:SoapExtensionAttribute
    {
        int _priority = 1;

        public override int Priority
        {
            get
            {
                return _priority;
            }
            set
            {
                _priority = value;
            }
        }

        public override Type ExtensionType
        {
            get { return typeof(MyExtension); }//定义扩展soap的类型
        }
    }

这个SoapExtensionAttribute抽象类定义如下：

protected SoapExtensionAttribute();
        // 返回结果:
        //     SOAP 扩展的 System.Type。
        public abstract Type ExtensionType { get; }
        // 返回结果:
        //     SOAP 扩展的优先级。

 SOAP 扩展分配优先级，该优先级有助于确定当配置多个 SOAP 扩展以便使用 XML Web 服务方法时执行的相对顺序。SOAP 扩展的优先级越高，它的执行与通过网络发送或接收 SOAP 消息越近。SOAP 扩展属于三个优先级组中的任意一个。在每个组内，priority 属性区别每个成员。priority 属性越低，相对优先级就越高(0 是最高的)。
        public abstract int Priority { get; set; }

//以下为扩展的soapextension类

    public class MyExtension:SoapExtension
    {
       
        public override object GetInitializer(Type serviceType)
        {
            return GetType();
        }

        public override object GetInitializer(LogicalMethodInfo methodInfo, SoapExtensionAttribute attribute)
        {
            return null;
        }

        public override void Initialize(object initializer)
        {
          
        }

        //这个override的方法会被调用四次
        //分别是SoapMessageStage的BeforeSerialize,AfterSerialize,BeforeDeserialize,AfterDeserialize
        public override void ProcessMessage(SoapMessage message)
        {
            if (message.Stage == SoapMessageStage.AfterDeserialize) //反序列化后处理
            {
                bool check = false;
                foreach (SoapHeader header in message.Headers)
                {
                    if (header is CertficateSoapHeader)
                    {
                        CertficateSoapHeader myHeader = (CertficateSoapHeader)header;

                        if (myHeader.UserName == null || myHeader.PassWord == null)
                        {                          
                            break;
                        }

                        if (myHeader.UserName.Equals("LY") && myHeader.PassWord.Equals("LY"))
                        {
                            check = true;
                            break;
                        }
                    }
                }

                if (!check)
                {
                    throw new SoapHeaderException("认证失败", SoapException.ClientFaultCode);
                }
            }
        }
    }

通过SoapMessage中的stream可以获取发送和收到的流数据

上面的功能实现了soapheader的权限认证

实现上面的类后，我们就不需要在webmethod中进行判断，只需要加入相关的属性即可

如：

        public CertficateSoapHeader soapHeader;

        [ExtensionAttribute]
        [SoapHeader("soapHeader",Direction=SoapHeaderDirection.In)]
        [WebMethod]
        public string HelloWorld()
        {
             return "Hello World";
        }

客户端的调用和前面一样，可见在webservice中soapextension中的ProcessMessage就相当于一个拦截器，能对进入webmethod的stream进行相关的截获

测试代码如下

：下载/Files/fujinliang/WebService.rar