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Why .Net Sucks today

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csharpc++oop
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  • realJSOPR realJSOP

    The lack of multiple inheritance. Instead of using collections in their native appearance, I like to create a class that inherits from a desired collection type, like so:

    public class MyCollection : List<MyClass>

    I do this because it allows me to write code specific to that collection, such as custom Add/Remove methods. In this case, I want to create a custom event that these collections send when something happens. Because there's no multiple inheritance, I can't simply write a little base class that implements the custom event code, because I'm already inheriting the List object. Instead, I have to duplicate the event code in every class from which I wish to implement it. Grrr... I now return you to your government-mandated stupors.

    ".45 ACP - because shooting twice is just silly" - JSOP, 2010
    -----
    You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
    -----
    When you pry the gun from my cold dead hands, be careful - the barrel will be very hot. - JSOP, 2013

    U Offline
    U Offline
    U G Leander
    wrote on last edited by
    #9

    Why not write a class with your custom event code which inherits the List object, and then inherit this class in MyCollection/whatever? At least then you wouldn't have to duplicate the event code... ...or use the custom event code class as a Property in MyCollection? (just some thoughts, of course it may not work this way for your purposes...)

    1 Reply Last reply
    0
    • S Sascha Lefevre

      This wouldn't do?

      class EventCollection<T> : List<T>
      {
      // event methods
      }

      class MyCollection : EventCollection<MyClass>
      {
      // ...
      }

      If the brain were so simple we could understand it, we would be so simple we couldn't. — Lyall Watson

      U Offline
      U Offline
      U G Leander
      wrote on last edited by
      #10

      Oops, it took me too long to write my reply (see below) :^)

      1 Reply Last reply
      0
      • S Sascha Lefevre

        This wouldn't do?

        class EventCollection<T> : List<T>
        {
        // event methods
        }

        class MyCollection : EventCollection<MyClass>
        {
        // ...
        }

        If the brain were so simple we could understand it, we would be so simple we couldn't. — Lyall Watson

        realJSOPR Offline
        realJSOPR Offline
        realJSOP
        wrote on last edited by
        #11

        Why yes, that would work. But I still want multiple inheritance. :)

        ".45 ACP - because shooting twice is just silly" - JSOP, 2010
        -----
        You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
        -----
        When you pry the gun from my cold dead hands, be careful - the barrel will be very hot. - JSOP, 2013

        1 Reply Last reply
        0
        • D Duncan Edwards Jones

          When do you need it?

          M Offline
          M Offline
          Marc Clifton
          wrote on last edited by
          #12

          Duncan Edwards Jones wrote:

          When do you need it?

          The use case that I've come up against in the past is the ability to extend a UI control's behavior to include some common behaviors. For example, what I want is: class MySmartLabel : Label, CommonToAllControls {} The idea being here that I can implement behaviors in CommonToAllControls and access them through the derived instance, and the instance can access methods in CommonToAllControls. If I write it as an interface: public class MyLabel : Label, ICommonToAllControls {} I have to implement the interface functions in each class. At best, this means having stubby functions like void DoSomething() {commonality.DoSomething();} and, as you point out, use IoC to pass in an instance of ICommonToAllControls. Or, I can invert it:

          class CommonToAllControls
          {
          Control target;
          // ... common stuff I want to do ...
          }

          But then I lose the ability to reference, without casting, the specific properties/methods of a control when I need them. There are now other ways to skin the cat -- extension methods, for example. Now, arguably, one might say that multiple inheritance is bad design because it fixes the implementation, whereas I might want to vary the implementation of CommonToAllControls. I can to a large extend agree with that, it's just that interfaces are a sort of klunky half-way solution to that problem. Then again, maybe I've got some big gaping hole in my understanding of OOP! Marc

          Imperative to Functional Programming Succinctly Contributors Wanted for Higher Order Programming Project!

          P 1 Reply Last reply
          0
          • realJSOPR realJSOP

            The lack of multiple inheritance. Instead of using collections in their native appearance, I like to create a class that inherits from a desired collection type, like so:

            public class MyCollection : List<MyClass>

            I do this because it allows me to write code specific to that collection, such as custom Add/Remove methods. In this case, I want to create a custom event that these collections send when something happens. Because there's no multiple inheritance, I can't simply write a little base class that implements the custom event code, because I'm already inheriting the List object. Instead, I have to duplicate the event code in every class from which I wish to implement it. Grrr... I now return you to your government-mandated stupors.

            ".45 ACP - because shooting twice is just silly" - JSOP, 2010
            -----
            You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
            -----
            When you pry the gun from my cold dead hands, be careful - the barrel will be very hot. - JSOP, 2013

            Sander RosselS Offline
            Sander RosselS Offline
            Sander Rossel
            wrote on last edited by
            #13

            List<T> probably isn't the class you want to inherit anyway. Try Collection<T>[^] instead :rolleyes:

            Visit my blog at Sander's bits - Writing the code you need. Or read my articles at my CodeProject profile.

            Simplicity is prerequisite for reliability. — Edsger W. Dijkstra

            Regards, Sander

            S realJSOPR 2 Replies Last reply
            0
            • Sander RosselS Sander Rossel

              List<T> probably isn't the class you want to inherit anyway. Try Collection<T>[^] instead :rolleyes:

              Visit my blog at Sander's bits - Writing the code you need. Or read my articles at my CodeProject profile.

              Simplicity is prerequisite for reliability. — Edsger W. Dijkstra

              Regards, Sander

              S Offline
              S Offline
              Slacker007
              wrote on last edited by
              #14

              :thumbsup:

              1 Reply Last reply
              0
              • Sander RosselS Sander Rossel

                List<T> probably isn't the class you want to inherit anyway. Try Collection<T>[^] instead :rolleyes:

                Visit my blog at Sander's bits - Writing the code you need. Or read my articles at my CodeProject profile.

                Simplicity is prerequisite for reliability. — Edsger W. Dijkstra

                Regards, Sander

                realJSOPR Offline
                realJSOPR Offline
                realJSOP
                wrote on last edited by
                #15

                No, I really do want List.

                ".45 ACP - because shooting twice is just silly" - JSOP, 2010
                -----
                You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
                -----
                When you pry the gun from my cold dead hands, be careful - the barrel will be very hot. - JSOP, 2013

                1 Reply Last reply
                0
                • M Marc Clifton

                  John Simmons / outlaw programmer wrote:

                  The lack of multiple inheritance.

                  Yup. When you need it, you really need it, and interfaces are a pathetic replacement. Marc

                  Imperative to Functional Programming Succinctly Contributors Wanted for Higher Order Programming Project!

                  J Offline
                  J Offline
                  Jeremy Falcon
                  wrote on last edited by
                  #16

                  I'm glad I'm not the only one that thought that was a WTF thing to do in C#.

                  Jeremy Falcon

                  1 Reply Last reply
                  0
                  • realJSOPR realJSOP

                    The lack of multiple inheritance. Instead of using collections in their native appearance, I like to create a class that inherits from a desired collection type, like so:

                    public class MyCollection : List<MyClass>

                    I do this because it allows me to write code specific to that collection, such as custom Add/Remove methods. In this case, I want to create a custom event that these collections send when something happens. Because there's no multiple inheritance, I can't simply write a little base class that implements the custom event code, because I'm already inheriting the List object. Instead, I have to duplicate the event code in every class from which I wish to implement it. Grrr... I now return you to your government-mandated stupors.

                    ".45 ACP - because shooting twice is just silly" - JSOP, 2010
                    -----
                    You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
                    -----
                    When you pry the gun from my cold dead hands, be careful - the barrel will be very hot. - JSOP, 2013

                    P Offline
                    P Offline
                    Philippe Mori
                    wrote on last edited by
                    #17
                    1. You can use extension methods. 2) For future maintenance purpose, almost always a better idea to use composition instead of multiple inheritance. 3) If the list is a private member of a class, then the custom method could be added to that class instead. 4) You can also use composition and have a property that returns the list if for example, your class purpose is to build a list. In practice, you might loose a few minutes now but the application will usually be more maintainable if every class follow the SOLID principle. When refactoring code, complex hierarchy are much harder to work with...

                    Philippe Mori

                    1 Reply Last reply
                    0
                    • M Marc Clifton

                      Duncan Edwards Jones wrote:

                      When do you need it?

                      The use case that I've come up against in the past is the ability to extend a UI control's behavior to include some common behaviors. For example, what I want is: class MySmartLabel : Label, CommonToAllControls {} The idea being here that I can implement behaviors in CommonToAllControls and access them through the derived instance, and the instance can access methods in CommonToAllControls. If I write it as an interface: public class MyLabel : Label, ICommonToAllControls {} I have to implement the interface functions in each class. At best, this means having stubby functions like void DoSomething() {commonality.DoSomething();} and, as you point out, use IoC to pass in an instance of ICommonToAllControls. Or, I can invert it:

                      class CommonToAllControls
                      {
                      Control target;
                      // ... common stuff I want to do ...
                      }

                      But then I lose the ability to reference, without casting, the specific properties/methods of a control when I need them. There are now other ways to skin the cat -- extension methods, for example. Now, arguably, one might say that multiple inheritance is bad design because it fixes the implementation, whereas I might want to vary the implementation of CommonToAllControls. I can to a large extend agree with that, it's just that interfaces are a sort of klunky half-way solution to that problem. Then again, maybe I've got some big gaping hole in my understanding of OOP! Marc

                      Imperative to Functional Programming Succinctly Contributors Wanted for Higher Order Programming Project!

                      P Offline
                      P Offline
                      Philippe Mori
                      wrote on last edited by
                      #18

                      In such case, extension method is definitively the best solution if you don't need events and properties... Otherwise, I would use an interface and an helper class. The less coupled the code is, the easier it will be to maintain.

                      Philippe Mori

                      1 Reply Last reply
                      0
                      • realJSOPR realJSOP

                        The lack of multiple inheritance. Instead of using collections in their native appearance, I like to create a class that inherits from a desired collection type, like so:

                        public class MyCollection : List<MyClass>

                        I do this because it allows me to write code specific to that collection, such as custom Add/Remove methods. In this case, I want to create a custom event that these collections send when something happens. Because there's no multiple inheritance, I can't simply write a little base class that implements the custom event code, because I'm already inheriting the List object. Instead, I have to duplicate the event code in every class from which I wish to implement it. Grrr... I now return you to your government-mandated stupors.

                        ".45 ACP - because shooting twice is just silly" - JSOP, 2010
                        -----
                        You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
                        -----
                        When you pry the gun from my cold dead hands, be careful - the barrel will be very hot. - JSOP, 2013

                        S Offline
                        S Offline
                        Shelby Robertson
                        wrote on last edited by
                        #19

                        public class CollectionBase: List
                        {
                        //custom events
                        }

                        public class MyCollection : CollectionBase
                        {
                        }

                        Could be lack of sleep, but why wouldn't that work?

                        CPallini wrote:

                        You cannot argue with agile people so just take the extreme approach and shoot him. :Smile:

                        1 Reply Last reply
                        0
                        • realJSOPR realJSOP

                          The lack of multiple inheritance. Instead of using collections in their native appearance, I like to create a class that inherits from a desired collection type, like so:

                          public class MyCollection : List<MyClass>

                          I do this because it allows me to write code specific to that collection, such as custom Add/Remove methods. In this case, I want to create a custom event that these collections send when something happens. Because there's no multiple inheritance, I can't simply write a little base class that implements the custom event code, because I'm already inheriting the List object. Instead, I have to duplicate the event code in every class from which I wish to implement it. Grrr... I now return you to your government-mandated stupors.

                          ".45 ACP - because shooting twice is just silly" - JSOP, 2010
                          -----
                          You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
                          -----
                          When you pry the gun from my cold dead hands, be careful - the barrel will be very hot. - JSOP, 2013

                          S Offline
                          S Offline
                          snorkie
                          wrote on last edited by
                          #20

                          According to Eric Lippert, you don't need it... Why C# does not support multiple inheritance? - Stack Overflow[^]

                          Hogan

                          1 Reply Last reply
                          0
                          • realJSOPR realJSOP

                            The lack of multiple inheritance. Instead of using collections in their native appearance, I like to create a class that inherits from a desired collection type, like so:

                            public class MyCollection : List<MyClass>

                            I do this because it allows me to write code specific to that collection, such as custom Add/Remove methods. In this case, I want to create a custom event that these collections send when something happens. Because there's no multiple inheritance, I can't simply write a little base class that implements the custom event code, because I'm already inheriting the List object. Instead, I have to duplicate the event code in every class from which I wish to implement it. Grrr... I now return you to your government-mandated stupors.

                            ".45 ACP - because shooting twice is just silly" - JSOP, 2010
                            -----
                            You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
                            -----
                            When you pry the gun from my cold dead hands, be careful - the barrel will be very hot. - JSOP, 2013

                            P Offline
                            P Offline
                            PIEBALDconsult
                            wrote on last edited by
                            #21

                            There's always my way: Implanting Common Code in Unrelated Classes[^] :cool:

                            1 Reply Last reply
                            0
                            • realJSOPR realJSOP

                              The lack of multiple inheritance. Instead of using collections in their native appearance, I like to create a class that inherits from a desired collection type, like so:

                              public class MyCollection : List<MyClass>

                              I do this because it allows me to write code specific to that collection, such as custom Add/Remove methods. In this case, I want to create a custom event that these collections send when something happens. Because there's no multiple inheritance, I can't simply write a little base class that implements the custom event code, because I'm already inheriting the List object. Instead, I have to duplicate the event code in every class from which I wish to implement it. Grrr... I now return you to your government-mandated stupors.

                              ".45 ACP - because shooting twice is just silly" - JSOP, 2010
                              -----
                              You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
                              -----
                              When you pry the gun from my cold dead hands, be careful - the barrel will be very hot. - JSOP, 2013

                              C Offline
                              C Offline
                              Camilo Reyes
                              wrote on last edited by
                              #22

                              My previous team got around this by implementing 15 layers of bullshit inheritance. What? Not good enough? ;P

                              1 Reply Last reply
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