"Learning notes" C # interface

• Defining an interface using the interface keyword
• Interfaces define a group of members but do not implement them directly
• Implementing interfaces
  • Any class that implements an interface must implement all of its member methods
  • Interfaces cannot be instantiated directly
  • Interfaces can contain methods and property declarations and cannot contain fields
  • All properties and methods in the interface default to public
  • A subclass can inherit one parent class and implement multiple interfaces at the same time
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  1 usingSystem;2 3 namespaceInterfacedemo4 {5     //Food Interface6      Public Interface Food7     {8         //Properties are defined in the interface, and properties are not implemented9         floatPrice {Set;Get; }Ten  One         //in the interface, define the method A         //1. Cannot add access modifiers, default is public -         //2. The method in the interface cannot be implemented -         voidEat (); the     } -      Public InterfaceB -     { -  +     } -     //Apple class +     //Apple inherits from Class A and implements the food interface and the B interface A     //3. Once a class implements an interface, it must implement all the members defined in the interface at      Public classApple:food, B -     { -          Public float Price -         { -             Get -             { in                 return 1.5f; -             } to             Set +             { -                  This. Price =value; the             } *         } $         //implements the Eat method in food interfacePanax Notoginseng          Public voidEat () -         { theConsole.WriteLine ("after eating the apple, HP + ten"); +         } A     } the  +      Public classBanana:food, B -     { $          Public float Price $         { -             Get -             { the                 return 3.8f; -             }Wuyi             Set the             { -                  This. Price =value; Wu             } -         } About         //implements the Eat method in food interface $          Public voidEat () -         { -Console.WriteLine ("after eating the banana, HP +"); -         } A     } +     class Program the     { -         Static voidMain (string[] args) $         { theApple A =NewApple (); the a.eat (); the  the Console.WriteLine (a.price); -  in             //Polymorphic --Polymorphism using interface implementations theFood B =NewApple (); the b.eat (); About  the  theBanana ba =NewBanana (); the BA. Eat (); + Console.WriteLine (ba.price); -             //4. Can not instantiate interface directly the             //Food f = new food ();Bayi         } the     } the}

"Learning notes" C # interface