subclass

问题 As you can see below I have a super class (Article) and two sub classes. I want each of the sub classes to have a static array that shall hold all it's objects. abstract class Article { public static $articles = array(); // Variable for storing all the objects of each sub-class. public function add_Object_To_Array() { array_push(self::$articles, $this); } } class Report extends Article{} class Interview extends Article{} -Making two Report objects and adding them to their array: $tmp = new

问题 Within a method at runtime, is there a way to know if that method has been called via super in a subclass? E.g. module SuperDetector def via_super? # what goes here? end end class Foo include SuperDetector def bar via_super? ? 'super!' : 'nothing special' end end class Fu < Foo def bar super end end Foo.new.bar # => "nothing special" Fu.new.bar # => "super!" How could I write via_super? , or, if necessary, via_super?(:bar) ? 回答1: The ultimate mix between my other, @mudasobwa's and @sawa's

问题 The Scenario I'm making a program in Java that involves cars. NOTE: I've simplified this scenario (to the best of my ability) to make it both more general and easier to understand. I'm not actually working with cars. I've created a Cars class, which is a collection of Car objects. The Car object has a speed (double) and a year (int). The constructor takes the year as a parameter, for example: public class Car { private int year; private double speed; public Car(int year) { this.year = year; }

问题 I am currently subclassing UIView to create custom objects, they work perfectly fine In interface builder i drag and drop a uiview and I set the class name to my custom view, and in runtime the view will populate according to my code. QUESTION: Is it possible to make it so that my custom view DRAWS in interface builder, And maybe drag and drop my custom view ? 回答1: I've researched this myself a while back, as far as i know this is not possible using the iPhone SDK. When developing for the Mac

问题 If a class defined an annotation, is it somehow possible to force its subclass to define the same annotation? For instance, we have a simple class/subclass pair that share the @Author @interface. What I'd like to do is force each further subclass to define the same @Author annotation, preventing a RuntimeException somewhere down the road. TestClass.java: import java.lang.annotation.*; @Retention(RetentionPolicy.RUNTIME) @interface Author { String name(); } @Author( name = "foo" ) public

问题 When using drawRect for a custom UIButton subclass, it never seems to get called to draw the button when highlighted. Do I need to call setNeedsDisplay for my button in my touch events? 回答1: As far as i can tell there is no straight forward way to subclass UIButton. UIButton is not the actual class type that is returned by the initializers. UIButton is kind of a front for a series of private classes. Say you had: UIButton *myButton = [UIButton buttonWithType:UIButtonTypeRoundedRect]; NSLog(@

问题 I have a QLabel with a 'StyledPanel, raised' frame. It is clickable, by subclassing QLabel; class InteractiveLabel(QtGui.QLabel): def __init__(self, parent): QtGui.QLabel.__init__(self, parent) def mouseReleaseEvent(self, event): self.emit(QtCore.SIGNAL('clicked()')) However, a general opinion is that this 'Box' is not easily recognised as clickable. In an effort toward usability, I'd like the 'Box' to show it is clickable when the mouse is hovered over it. Obviously a reaction to a mouse

问题 There is a base class Base and a subclass Special . class Base(object): def __init__(self, name): self.name = name def greet(self): return 'Hello %s' % self.name class Special(Base): def __init__(self, name): super(Special, self).__init__(name) def rhyme(self): return 'Hi %s! How are you? Fine, thanks. What about you?' % self.name How can I turn an instance of Base into an instance Special ? Currently I have a classmethod defined on Special that just reassignes __dict__ : class Special(Base):

问题 Python print isn't using __repr__ , __unicode__ or __str__ for my unicode subclass when printing. Any clues as to what I am doing wrong? Here is my code: Using Python 2.5.2 (r252:60911, Oct 13 2009, 14:11:59) >>> class MyUni(unicode): ... def __repr__(self): ... return "__repr__" ... def __unicode__(self): ... return unicode("__unicode__") ... def __str__(self): ... return str("__str__") ... >>> s = MyUni("HI") >>> s '__repr__' >>> print s 'HI' I'm not sure if this is an accurate

问题 I'm working on extending the Python webapp2 web framework for App Engine to bring in some missing features (in order to make creating apps a little quicker and easier). One of the requirements here is that each subclass needs to have some specific static class variables. Is the best way to achieve this to simply throw an exception if they are missing when I go to utilise them or is there a better way? Example (not real code): Subclass: class Bar(Foo): page_name = 'New Page' page_name needs to