asp.net(c#)获取存储过程返回值

CREATE proc sp_uptmp @tmpName varchar(50),@srcPos varchar(255)
as

Begin TRAN
insert into t_template values(@tmpName,@srcPos)
COMMIT

return isnull(@@identity,0)
GO


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在 ado.net 里面获取返回值的方法为(c#):
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SqlConnection dbconn = new SqlConnection(connStr);
SqlCommand cmd = new SqlCommand("sp_uptmp",dbconn);
cmd.CommandType = CommandType.StoredProcedure;

SqlParameter tmpName = cmd.Parameters.Add("@tmpName",SqlDbType.VarChar);
SqlParameter srcPos = _cmd.Parameters.Add("@srcPos",SqlDbType.VarChar);
SqlParameter rtnval = cmd.Parameters.Add("rval",SqlDbType.Int);

tmpName.Direction = ParameterDirection.Input;
srcPos.Direction = ParameterDirection.Input;
rtnval.Direction = ParameterDirection.ReturnValue;

tmpName.Value = "";
srcPos.Value = "";
dbconn.Open();
cmd.ExecuteNonQuery();
dbconn.Close();

tmpid = (int)rtnval.Value; //此处即为返回值