Bridge in design mode Learning)

Purpose:Separate the abstract part from its implementation part so that they can all change independently.
Implementation points:Separation and aggregation. Divides an object into two parts. They are maintained by aggregation.
UML:

Code:In this example, the electrical switch function is separated from the switch function to adapt to different changes.

    Public    Abstract     Class  SW
{
  Public     Abstract    Void  Openandclose ();
}
  //  Unidirectional Switch  
    Class  Singlesw: SW
{
  Public     Override     Void  Openandclose ()
{
Console. writeline (  " This is a single switch!  "  );
}
}
  //  Bidirectional Switch  
    Class  Doublesw: SW
{
  Public     Override     Void  Openandclose ()
{
Console. writeline (  " This is a double switch !!  "  );
}
}

  Public     Abstract     Class  El_device
{
  Protected  SW _ switcher;
  Public  SW switcher
{
  Set  {_ Switcher  = Value ;}
}
  Public     Virtual     Void  Openandclose ()
{
_ Switcher. openandclose ();
}
}
  //  Refrigerator class, playing the role of bridging  
    Public     Class  Frigde: el_device
{
 Public     Override     Void  Openandclose ()
{
_ Switcher. openandclose ();
}
}
  //  ------------------------- Execute --------------------------  
     Class  Program
{
  Static     Void Main (  String  [] ARGs)
{
  //  Xinfei refrigerator is a one-way switch  
  El_device Xinfei  =     New  Frigde ();
Xinfei. switcher  =     New  Singlesw ();
  // Midea refrigerator is a two-way switch  
  El_device Meidi  =     New  Frigde ();
Meidi. switcher  =     New  Doublesw ();

Xinfei. openandclose ();
Meidi. openandclose ();
Console. Readline ();
}
}