WCF 序列化 Type对象

Question

现在我有一个方法：public object Fetch(Type objectType){}这个方法调用一个WCF的方法，并且把objectType作为参数传进去，因为WCF不能很好的序列化Type类型，所以每次都是报错：Type 'System.RuntimeType' with data contract name 'RuntimeType:http://schemas.datacontract.org/2004/07/System' is not expected. Add any types not known statically to the list of known types - for example, by using the KnownTypeAttribute attribute or by adding them to the list of known types passed to DataContractSerializer.希望大家帮忙？怎么解决