关于xml序列化报Use the XmlInclude or SoapInclude attribute to specify types that are not known statically.

        在进行xml序列化时，正常单个类可以正常序列化，当遇到派生类时，就会报错The type xx' was not expected.Use the XmlInclude or SoapInclude attribute to specify types that are not known statically.如下图情况：

        

当我们使用MessageResponseHeader时就会报上述错误，

第一种方法是在基类添加XmlInclude特性

 第二种方法就是在XmlSerializer的构造函数内指定派生类型

var xs =new XmlSerializer(typeof(MessageResponseHeader), new Type[] {typeof(MessageHeader) });