C# Notes

• Operator Overloading: the operator must be defined in the same type on which it performs the operation.

  private void btnStart_Click(object sender, System.EventArgs e)
  {
   MyClass myClass1 = new MyClass();
   MyClass myClass2 = new MyClass();
   myClass1.MyStringField = "Hello ";
   myClass2.MyStringField = "World!";
   // Displays: Hello World!
   MessageBox.Show((myClass1 + myClass2).MyStringField);
   // Displays: Hello 1
   MessageBox.Show((myClass1 + 1).MyStringField);
  }
  
  
  public class MyClass 
  {
   public String MyStringField = "";
   public static MyClass operator + (MyClass myClass1, MyClass myClass2) 
   {
    MyClass myClass = new MyClass();
    myClass.MyStringField = myClass1.MyStringField + myClass2.MyStringField;
    return myClass;
   }
   public static MyClass operator + (MyClass myClass, int Number) 
   {
    myClass.MyStringField += Number.ToString();
    return myClass;
   }
  }
  

• Making sure only an interface type can access an interface's members:

    private void btnStart_Click(object sender, System.EventArgs e)
    {
     // MyMethod() not accessible from mc:
     MyClass mc = new MyClass();
     // MyMethod() is accessible from imc:
     IMyClass imc = new MyClass();
     imc.MyMethod();
    }
  
    private interface IMyClass 
    {
     void MyMethod();
    }
  
    private class MyClass : IMyClass
    {
     // This method only accessible via a IMyClass type:
     void IMyClass.MyMethod() {}
    }