今天写WCf 时遇到如下报错：

调试过程发现，各个过程都无异常，但是返回给调用端数据时出现如下错误。

Failed to invoke the service. Possible causes: The service is offline or inaccessible; the client-side configuration does not match the proxy; the existing proxy is invalid. Refer to the stack trace for more detail. You can try to recover by starting a new proxy, restoring to default configuration, or refreshing the service.

最后检查，导致此错误的原因是
[DataContract]
    public class Student
    {
        [DataMember]
        public int PersonId { get; }
        [DataMember]
        public string Name { get; set; }
        
    }
    
    改成如下就好了：
    [DataContract]
    public class Student
    {
        [DataMember]
        public int PersonId { get;private set; }
        [DataMember]
        public string Name { get; set; }
        
    }
    
   wcf 服务序列化只读属性会出现问题，导致Failed to invoke the service.