overriding

What is the purpose of an abstract method?

由 纵饮孤独 提交于 2019-12-06 05:59:05
abstract public class car { abstract void drive(); } As in the code snippet above, what exactly is the purpose of an abstract method in Java? From what I can gather, by definition, they aren't allowed to have bodies. When you make things implement the same abstract class, you are saying, these things are alike at a high level, but they vary in the particulars of how they do things. An abstract method is how you say, "Here's something that all the things that extend this class have to do, but they each get to specify how exactly they will do it." By declaring a method abstract you are not

Magento Override getPrice()

由 牧云@^-^@ 提交于 2019-12-06 05:51:01
问题 I have overrode the price rule of Magento product by overriding the getPrice() method in " Mage_Catalog_Model_Product_Type_Price " class, simple products are working fine and show the updated price which I mentioned in getPrice() i.e public function getPrice($product) { return 80; } But in the case of downloadable products it shows the original price, Any one here can tell me how can I override price in downloadable products. Thanks 回答1: I would guess that this will be chased down to the

OverrideComponent with TestBed

由 こ雲淡風輕ζ 提交于 2019-12-06 05:47:33
问题 I have MainComponent that uses ChildComponentA as a @ViewChild . MainComponent is calling a method on ChildComponentA . I want to write an unit test case mocking ChildComponentA . How can I do this using TestBed (in Angular 2 RC5)? Before I used to use overrideDirective(MainComponentName, ChildComponentA, MockChildComponentA); Is there an equivalent to this using TestBed ? I tried using TestBed.overrideComponent(ChildComponentA,{ set: { template: '<div></div>' } }); which just sets the

Override the enter key, but keep default behavior for other keys in a wpf datagrid

由 喜你入骨 提交于 2019-12-06 05:27:28
问题 It really bothers me that the pressing the enter key in a Datagrid moves the selection down one item, I'd like to be able to decide what it does in a normal keydown event. So what I did was create a new class that inherits DataGrid and override the OnKeyDown event and use that as my datagrid. This creates a whole new set of problems, since I apparently have to rewrite all the other keypresses (arrow key navigation, shift+arrow key selection, pgup/pgdn, etc..). I've been trying to hack it, but

Customize display of an enumeration class

由 旧城冷巷雨未停 提交于 2019-12-06 05:22:21
I'd like to customize the display of an enumeration class using matlab.mixin.CustomDisplay . If I have a regular (non-enumeration) class such as the following: classdef test < handle & matlab.mixin.CustomDisplay properties value end methods function obj = test(value) obj.value = value; end end methods (Access = protected) function displayScalarObject(obj) disp(['hello ', num2str(obj.value)]) end end end then everything works fine - for example, >> a = test(1) a = hello 1 But if I have an enumeration class such as the following (note the addition of the enumeration block): classdef test <

Objective C Method Swizzling using dynamic library

由 有些话、适合烂在心里 提交于 2019-12-06 04:14:29
问题 I am trying to learn method swizzling. I have created a program in objective C which just calls a method within its class. Now my I am trying to load a dynamic library using DYLD_INSERT_LIBRARIES so I can override my method implementation with new method which is defined in my dynamic library. The aim is to modify the argument and then call the original function call. Program code is available at http://pastebin.com/a0b3qkgB The code for dynamic library is available at http://pastebin.com

Override method in inherited interface with subtype with generics

由 爷，独闯天下 提交于 2019-12-06 03:36:56
问题 I have the following hierarchy in java: interface ObserverA {} interface A { void method1(); addObserver(Observer o); } And I want to extend it like this: interface ObserverB extends ObserverA{} interface B extends A { void method2(); addObserver(ObserverB o); } in such a way that the addObserver() method of B would override the same method in A . As it is it doesn't work, implementations of B would need to implement both versions of addObserver() , I wan't to have just one. Can this be done

function overriding with different return types

由 非 Y 不嫁゛ 提交于 2019-12-06 02:33:07
问题 Does the return type influence on function overriding? (As far as I know return typde is not a part of a function/method signature) In a base class I have a function, which doesn't get arguments, returns int and is pure virtual. In each derived class, I define an enum for the return type.The function is overridden in the derived classes, i.e. it has the same signature but different behavior. The question is: Is that legal for overriding and return type is not a part of function overriding?

Overriding multiple inherited templated functions with specialized versions

由 你离开我真会死。 提交于 2019-12-06 02:26:12
问题 Okay, sample code first; this is my attempt at communicating what it is that I'm trying to do, although it doesn't compile: #include <iostream> template <class T> class Base { public: virtual void my_callback() = 0; }; class Derived1 : public Base<int> , public Base<float> { public: void my_callback<int>() { cout << "Int callback for Derived1.\n"; } void my_callback<float>() { cout << "Float callback for Derived\n"; } }; class Derived2 : public Base<int> , public Base<float> { public: void my

How to override a virtual function with a non-virtual function?

由 那年仲夏 提交于 2019-12-06 02:17:25
Refer to this question: Hide virtual function with non-virtual override And this question: override on non-virtual functions A function that overrides a virtual function is virtual too, even though it's not explicitly declared virtual. My technical question is: Is there away to make that overriding function non-virtual (and applies that to classes lower in the hierarchy)? In other words, can I turn the "virtuality" off? Obviously we can override a non-virtual function with a virtual function. Can we do the opposite, i.e. to override a virtual function with a non-virtual function? You are
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