Getting DateTime from stored procedure error

Question

I am trying to pull a DateTime from a stored procedure on my SQL Server.

Stored procedure variable:

@TempDateTime DateTime = '' OUTPUT
SET @TempDateTime = GETDATE()

Line that errors out in my C# CF 2.0 Program

DateTime tempDT = Convert.ToDateTime(sqlcmd.Parameters["@TempDateTime"].Value);

I get the following error, and I am at a lost on what it is. Can my stored procedure be sending back a null? I execute the stored procedure and it runs fine, on another bit of code. Getting the DateTime and inserting it into a table, but errors when I try to retrieve the DateTime var.

System.IndexOutOfRangeException was unhandled
Message="An {0} with {1} '{2}' is not contained by this {3}."

StackTrace:
at System.Data.SqlClient.SqlParameterCollection.RangeCheck()
at System.Data.SqlClient.SqlParameterCollection.get_Item()
at Missouri_Scanning_Utility.Form1.updateDatabase()
at Missouri_Scanning_Utility.Form1.tmrUpdateDatabase_Tick()
at System.Windows.Forms.Timer._WnProc()
at System.Windows.Forms.ApplicationThreadContext._InternalContextMessages()
at Microsoft.AGL.Forms.EVL.EnterMainLoop()
at System.Windows.Forms.Application.Run()
at Missouri_Scanning_Utility.Program.Main()

Answer 1

When you are defining the parameter values to your send to your call, you have to declare the OUTPUT parameters accordingly.

Since you do not have the relevant portions of your code posted, here is the general procedure for doing this:

var tempDateTimeParam = new SqlParameter("@TempDateTime", SqlDbType.DateTime)
{ 
    Direction = ParameterDirection.Output 
};

myCommand.CommandType = CommandType.StoredProcedure;
myCommand.Parameters.Add(tempDateTimeParam);
// Add additional params.

// Execute stored proc.

// Read result from output param which should now have a value.
var tempDateTimeValue = (DateTime)tempDateTimeParam.Value;