List with Parameter’s object name gets Prefixed with @

Before passing to the Stored Procedure, all the parameters will be prefixed with @. i.e, outside the region of my foreach loop and from the second iteration all the parameters name will prefixed to @ and getting an exception message from the second iteration, when a call is made to the stored procedure

{"Procedure or function UspUpdateProctorSignalByScheduleUserID has too many arguments specified."}

Here is the partial code of the snippets shown below:

[WebMethod]
public static List UpdateAllProctorStatus(ProctoringScheduledUserInfoList scheduledUsersList)
{
#region Outside of foreach loop parameter's name will be prefixed to @ from the second iteration of the loop
List<object> parameters = new List<object>();
parameters.Add(SqlHelper.BuildSqlParameter("Status", SqlDbType.VarChar, 10, "status", null, ParameterDirection.Output));
if (proctorStatus == "PAUSE")
parameters.Add(SqlHelper.BuildSqlParameter("ScheduleExtensionTime", SqlDbType.Int, sizeof(Int16), "ScheduleExtensionTime", scheduledUsersList.PauseTime));
parameters.Add(SqlHelper.BuildSqlParameter("ProctorSignal", SqlDbType.TinyInt, sizeof(Int16), "ProctorSignal", scheduledUsersList.ProctorSignal));
#endregion
foreach (Int64 scheduleUserID in scheduledUsersList.ScheduleUserID)
{
parameters.Add(SqlHelper.BuildSqlParameter("ScheduleDetailUserID", SqlDbType.BigInt, sizeof(Int64), "ScheduleDetailUserID", scheduleUserID));
proctoringUserListDT = SqlHelper.ExecuteDataTable(CommandType.StoredProcedure, "UspUpdateProctorSignalByScheduleUserID", parameters.ToArray(), false);
if (proctorStatus == "PAUSE")
parameters.RemoveAt(3);
else
parameters.RemoveAt(2);
}
}

Actual Result:

a. For the I iteration

parameters | Count = 4

[0] {Status}

Value null

[1] {ScheduleExtensionTime}

Value 0

[2] {ProctorSignal}

Value 1

[3] {ScheduleDetailUserID}

Value 943417

declare @p1 varchar(10)

set @p1='S001'

exec UspUpdateProctorSignalByScheduleUserID @Status=@p1 output,@ScheduleExtensionTime=0,@ProctorSignal=1,@ScheduleDetailUserID=943417

select @p1

b. For the II iteration

parameters | Count = 4

[0] {@Status}

Value "S001"

[1] {@ScheduleExtensionTime}

Value 0

[2] {@ProctorSignal}

Value 1

[3] {ScheduleDetailUserID}

Value 943419

declare @p1 varchar(10)

set @p1=NULL

exec UspUpdateProctorSignalByScheduleUserID @@Status=@p1 output,@@ScheduleExtensionTime=0,@@ProctorSignal=1,@ScheduleDetailUserID=943419

select @p1

Expected Result:

b. For the II iteration

parameters | Count = 4

[0] {Status}

Value null

[1] {ScheduleExtensionTime}

Value 0

[2] {ProctorSignal}

Value 1

[3] {ScheduleDetailUserID}

Value 943419

declare @p1 varchar(10)

set @p1='S001'

exec UspUpdateProctorSignalByScheduleUserID @Status=@p1 output,@ScheduleExtensionTime=0,@ProctorSignal=1,@ScheduleDetailUserID=943419

select @p1

Here the property gets changed from the second iteration onward

> ParameterName = "@Status"

> ParameterNameFixed = "@Status"

> _parameterName = "@Status"

The same piece of snippets when declared and initialized within foreach loop works perfectly.

But inside the foreach loop, the condition if (proctorStatus == "PAUSE") checks whether to remove parameters.RemoveAt(3); the list at particular index 3 or not.

Does the same condition can be written making use of LINQ or Lambda operator i.e, by removing the object for particular ScheduleDetailUserID within each iteration of the loop?