Notes for future development

1. The Enumeration type must have a default value.

An Enumeration type is usually used to indicate whether the value is null or not assigned a value.

If no value is assigned, an error message indicating the second is displayed during the transfer of WCF.

I have seen: "An existing connection was forcibly closed by the remote host ",

"System. collections. listdictionaryinternal \ r \ n data: An error occurred while loading ing the HTTP Response to SVC path. this cocould be due to the service endpoint binding not using the HTTP protocol. this coshould 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."

If you encounter such a prompt when using WCF, first check whether the transmitted data contains an enumeration type without assigning a value.