C#

ListBox1.DataSource = payItemClass.GetPayItems();
ListBox1.DisplayMember = "PayItem.Code";
ListBox1.ValueMember = "PayItem.Id";

private void CheckExcelfile()
       {
           string path = @"C:\Servicedeatils.xls";
           if (!File.Exists(path))
           {
               using (StreamWriter sw = File.CreateText(path))
               {
               How to add columns to the created excel file??

               }
           }


       }

public class Student : INotifyPropertyChanged
   {       
           const int MINIMUM_AGE = 1;
           int rollNumber = 0;
           int age = 0;
           string studentName = string.Empty;
    
           #region INotifyPropertyChanged Members
           public event PropertyChangedEventHandler PropertyChanged;
           #endregion
    
           public Student() { }
           public Student(string studentName, int age, int rollNumber)
           {           
               this.StudentName = studentName;
               this.StudentAge = age;
               this.RollNumber = rollNumber;
           }
    
           public string Name
           {
               get
               {
                   return this.studentName;
               }
               set
               {
                   if (value != this.studentName)//guard clause
                   {
                       if (value.Trim() == string.Empty)
                           throw new Exception("Name assigned does not confirms to the format. Please assign a proper alphanumeric value.");
                       this.studentName = value;
                       this.DisplayPropertyChange("StudentName");
                   }
               }
           }
    
           public int StudentAge
           {
               get
               {
                   return this.age;
               }
               set
               {
                   if (value != this.age)//guard clause
                   {
                       //any value lesss than minumum age goes to minimum ages.
                       if (value < MINIMUM_AGE)
                           this.age = MINIMUM_AGE;                                   
                       else
                           this.age = value;
                        this.DisplayPropertyChange("StudentAge");
                   }
               }
           }
    
           public int RollNumber
           {
               get
               {
                   return this.rollNumber;
               }
               set
               {
                   if (value != this.rollNumber)//guard clause
                   {
                       if (value < 0)
                           throw new Exception("Wrong value supplied. Only non negative integers allowed.");
                       this.rollNumber = value;
                       this.DisplayPropertyChange("RollNumber");
    
                   }
               }
           }
    
           void DisplayPropertyChange(string propertyName)
           {
               if (null!=this.PropertyChanged)
               {
                   this.PropertyChanged(this,new PropertyChangedEventArgs(propertyName));
               }
           }        
   }

public class StudentName
 {
       string firstName = string.Empty;
       string lastName = string.Empty;

       public string FirstName
       {
           get { return firstName; }
           set { firstName = value; }
       }
       public string LastName
       {
           get { return lastName; }
           set { lastName = value; }
       }

       public string FullName
       {
           get { return String.Concat(this.firstName," ",this.lastName); }
       }
       //Default
       public StudentName()
       {}
       //Overloaded
       public StudentName(string firstName, string lastName)
       {
           this.firstName = firstName;
           this.lastName = lastName;
       }
}

Student student=new Student();
  string.Format("The student's name is {0}",student.Name.FullName);

public List<string> GetSerialDevice()
        {

            // Get a list of serial port names.
            
            
            strPorts = SerialPort.GetPortNames();

            List<string> strAmplifiers = new List<string>();

            //Console.WriteLine("The following serial ports were found:" );

        //    // Display each port name to the console.
        //    foreach (string strPort in strPorts)
        //    {
        //        Console.WriteLine(strPort);
        //    }
            


            foreach (string strPort in strPorts)
            {
                serialPort1 = new SerialPort(strPort, 115200, Parity.None, 8, StopBits.One);
                serialPort1.Handshake = Handshake.None;
                serialPort1.Close();
                serialPort1.ReadTimeout = 500;
                serialPort1.WriteTimeout = 500;
                serialPort1.Open();
                serialPort1.WriteLine("!001:USR1?\r");
                string strUSR1Return = serialPort1.ReadTo("\r");

                //Console.WriteLine(USR1Return);


                //Each unit will need to have 2.0 written to USR1 for this to work properly
                if (strUSR1Return == "+2.000000")
                {
                    serialPort1.WriteLine("!001:SERL?\r");
                    string strSerialLow = serialPort1.ReadTo("\r");
                    serialPort1.WriteLine("!001:SERH?\r");
                    string strSerialHigh = serialPort1.ReadTo("\r");
                    //SN coding per mfg
                    double dblSerialNumber = double.Parse(strSerialHigh) * 65536 + double.Parse(strSerialLow);
                    Console.WriteLine("On" + " " + strPort + " " + "there is a valid amplifier with S/N "
                        + dblSerialNumber.ToString());

                    strAmplifiers.Add(dblSerialNumber.ToString());
                    
                                           
                }//End of if
                
            }//End of foreach
            Console.WriteLine(strAmplifiers[0]);

            serialPort1.Close();

            return strAmplifiers;