To get output decimal val

create procedure SPName
(
  @par1 int,
  @outParameter varchar output
)
as 
begin
   --insert upadate query or whatever
   --assign value to outparameter
   set   @outParameter='1.1'

end

SqlParameter outParameter = new SqlParameter("@outParameter", SqlDbType.VarChar, 255); 
                outParameter.Direction = ParameterDirection.InputOutput;
                outParameter.Value = "";
                _sqlCmd.Parameters.Add(outParameter);
                _sqlCmd.ExecuteScalar();
                _transaction.Commit();
//to get value of out parameter
string outvalue = _sqlCmd.Parameters["@outParameter"].Value.toString();