WCF 数据结构中返回的只读属性 TotalCount 也需要声明 Set 方法。

[DataContract]
public class BookShelfDataModel
{
    public BookShelfDataModel()
    {
        BookList = new List<BookDataModel>();
    }
    [DataMember]
    public List<BookDataModel> BookList { get; set; }
    [DataMember]
    public int TotalCount { get { return BookList.Sum(t => t.Count); } set { } }
}

未声明 Set 方法将抛出异常如下：

System.Exception: {"ClassName":"System.ServiceModel.CommunicationException","Message":"An error occurred while receiving the HTTP response to http://localhost:6274/TestService.svc. This could be due to the service endpoint binding not using the HTTP protocol. This could also be due to an HTTP request context being aborted by the server (possibly due to the service shutting down). See server logs for more details.","Data":{},"InnerException":{"ClassName":"System.Net.WebException","Message":"The underlying connection was closed: An unexpected error occurred on a receive.","Data":{},"InnerException":{"ClassName":"System.IO.IOException","Message":"Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host.","Data":{},"InnerException":{"NativeErrorCode":10054,"ClassName":"System.Net.Sockets.SocketException","Message":"An existing connection was forcibly closed by the remote host","Data":{},"InnerException":null,"HelpURL":null,"StackTraceString":" at System.Net.Sockets.Socket.Receive(Byte[] buffer, Int32 offset, Int32 size, SocketFlags socketFlags)\r\n at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)","RemoteStackTraceString":null,"RemoteStackIndex":0,"ExceptionMethod":"8\nReceive\nSystem, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089\nSystem.Net.Sockets.Socket\nInt32 Receive(Byte[], Int32, Int32, System.Net.Sockets.SocketFlags)","HResult":-2147467259,"Source":"System","WatsonBuckets":null},"HelpURL":null,"StackTraceString":" at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)\r\n at System.Net.PooledStream.Read(Byte[] buffer, Int32 offset, Int32 size)\r\n at System.Net.Connection.SyncRead(HttpWebRequest request, Boolean userRetrievedStream, Boolean probeRead)","RemoteStackTraceString":null,"RemoteStackIndex":0,"ExceptionMethod":"8\nRead\nSystem, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089\nSystem