Stored procedure cannot get return type parameter

Common people will use SqlDataReader to do the return result set, but if the business has a return parameter, the argument is empty value, and the stored procedure has the value of this parameter,

If there is no problem with a DataTable, the reason is that the DataReader query has been disconnected before the return parameter is stored, so the value is not saved, so it is null.

The DataTable saves all the data and then disconnects the link, so the value is taken out. This thing is really troublesome, I hope you do not go this detour in the future.

Stored procedure cannot get return type parameter