overriding

.NET events - blocking subscribers from subscribing on an event

由 ≡放荡痞女 提交于 2019-12-04 19:58:18
问题 Let's say I have a "Processor" interface exposing an event - OnProcess. Usually the implementors do the processing. Thus I can safely subscribe on this event and be sure it will be fired. But one processor doesn't do processing - thus I want to prevent subscribers to subscibe on it. Can I do that? In other words in the code below I want the last line to throw an exception: var emptyProcessor = new EmptyProcessor(); emptyProcessor.OnProcess += event_handler; // This line should throw an

How to “override” a defined (get-)property on a prototype?

由 帅比萌擦擦* 提交于 2019-12-04 19:13:21
问题 I have some code which defines a getter (but no setter, if such is relevant) on a prototype. The value returned is correct in 99.99% of the cases; however, the goal is to set the property to evaluate to a different value for a specific object. foo = {} Object.defineProperty(foo, "bar", { // only returns odd die sides get: function () { return (Math.random() * 6) | 1; } }); x = Object.create(foo); x.bar // => eg. 5 x.bar = 4 // by fair dice roll x.bar // nope => eg. 3 How can the property be

C++ Overridden method not getting called

由 安稳与你 提交于 2019-12-04 18:48:38
问题 Shape.h namespace Graphics { class Shape { public: virtual void Render(Point point) {}; }; } Rect.h namespace Graphics { class Rect : public Shape { public: Rect(float x, float y); Rect(); void setSize(float x, float y); virtual void Render(Point point); private: float sizeX; float sizeY; }; } struct ShapePointPair { Shape shape; Point location; }; Used like this: std::vector<Graphics::ShapePointPair> theShapes = theSurface.getList(); for(int i = 0; i < theShapes.size(); i++) { theShapes[i]

How to override a field in the parent class

由 早过忘川 提交于 2019-12-04 18:32:10
问题 I have parent and child classes in Django model. And I want to fill a field in parent class when initialize child class. Or override this field in child class. class Parent(models.Model): type = models.CharField() class Child(Parent): type = models.CharField() //Doesn't work Also trying override init method, but it doesn't work too. How can I accomplish this? 回答1: In normal Python class inheritance, it is permissible for a child class to override any attribute from the parent class. In Django

Angular2: How to override components template?

由 谁说胖子不能爱 提交于 2019-12-04 18:23:30
问题 I am considering migrating an angular 1.4 application to angular 2 and I wonder if it will be possible to override components' template like we do in angular1 using $provide.decorator (like Can you override specific templates in AngularUI Bootstrap?). I am looking for something like TestComponentBuilder.overrideTemplate but for a non-testing scenario. Does Angular2 comes with something similar? 回答1: Check out this answer from stackoverflow Override/extend third-party component's template. The

Java Eclipse @Override error

由 这一生的挚爱 提交于 2019-12-04 18:14:35
问题 I'm writing a Java class that's implementing an interface called Command, which contains the methods isValid() and run() , as follows: public class DailyEnergy implements Command { @Override public boolean isValid(String command) { return false; } @Override public void run(String command) throws Exception { } } and here's the Command.java file: public interface Command { public boolean isValid(String command); public void run(String command) throws Exception; } Within this class, I'm

Overriding User Library Classes in Java

由 不羁岁月 提交于 2019-12-04 18:13:36
I code java with BlueJ for Mac. I have added the stdlib.jar library (From princeton http://introcs.cs.princeton.edu/java/stdlib/ ). Before added this library I had my own class named StdDraw.java (The specific class I was using on the project) and copy/pasted the code. I also adjusted some of the code and added some new lines. Since I cannot edit the libraries code, how may I override or extend library classes to add additional functionality? Since the library classes are final , you can't extend them. Another option is to wrap them in your own classes. For example, you can create your own

Java - Upcasting and Downcasting

由 ♀尐吖头ヾ 提交于 2019-12-04 18:12:06
I Knew there are plenty of articles/questions in stackoverflow describing about upcasting and downcasting in Java. And I knew what is upcasting and downcasting. But my question is not specfic to that. Upcasting - Conversion from child to parent - Compiler takes care. No cast is required Downcasting - Conversion from parent to child - Explicit cast is required public class Animal { public void getAnimalName(){ System.out.println("Parent Animal"); } } public class Dog extends Animal{ public void getDogName(){ System.out.println("Dog"); } } public static void main(String[] args) { Dog d = new Dog

Is it possible to override a method with a derived parameter instead of a base one?

由 ∥☆過路亽．° 提交于 2019-12-04 18:09:44
问题 I'm stuck in this situation where: I have an abstract class called Ammo , with AmmoBox and Clip as children. I have an abstract class called Weapon , with Firearm and Melee as children. Firearm is abstract, with ClipWeapon and ShellWeapon as children. Inside Firearm , there's a void Reload(Ammo ammo); The problem is that, a ClipWeapon could use both a Clip and an AmmoBox to reload: public override void Reload(Ammo ammo) { if (ammo is Clip) { SwapClips(ammo as Clip); } else if (ammo is AmmoBox

Override Javascript Function Based on Passed Parameters

由 风流意气都作罢 提交于 2019-12-04 17:43:44
Is it possible to override a function based on the number of parameters that you are passing into it? For instance: function abc(name) { document.write ('My name is' + name); } function abc(name,friend) { document.write ('My name is' + name + 'and my best friend\'s name is' + friend); } So in the HTML if I just called abc(george) it would use the first version of the function, but if I called abc(george,john) it would use the second version. There may be other ways to accomplish the example I used, but I'm just wondering if the concept is sound in javascript. JavaScript does not support
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