User-defined Custom Exception in C#

C# exceptions are represented by classes. The exception classes in C# are mainly directly or indirectly derived from the System.Exception class.

You can also define your own exception. User-defined exception classes are derived from the Exception class.

The following is an example −

Example

using System; namespace UserDefinedException {    class TestTemperature {       static void Main(string[] args) {          Temperature temp = new Temperature();          try {             temp.showTemp();          } catch(TempIsZeroException e) {             Console.WriteLine("TempIsZeroException: {0}", e.Message);          }          Console.ReadKey();       }    } } public class TempIsZeroException: Exception {    public TempIsZeroException(string message): base(message) {    } } public class Temperature {    int temperature = 0;    public void showTemp() {       if(temperature == 0) {          throw (new TempIsZeroException("Zero Temperature found"));       } else {          Console.WriteLine("Temperature: {0}", temperature);       }    } }