overriding

An abstract method overrides an abstract method

由 与世无争的帅哥 提交于 2019-12-04 03:28:22
问题 public abstract class A { public abstract void Process(); } public abstract class B : A { public abstract override void Process(); } public class C : B { public override void Process() { Console.WriteLine("abc"); } } This code throws an Compilation Error: 'B' does not implement inherited abstract member 'A.Process()'. Is there any way to do this? 回答1: Just leave out the method completely in class B. B inherits it anyway from A, and since B itself is abstract, you do not explicitly need to

Why is overriding ActiveRecord::Base.initialize wrong?

由 扶醉桌前 提交于 2019-12-04 03:24:51
问题 In several places, I've seen claims that overriding ActiveRecord::Base.initialize is wrong because it might not always be called: How can I set default values in ActiveRecord? http://blog.dalethatcher.com/2008/03/rails-dont-override-initialize-on.html With never versions of ActiveRecord (3.0+), is this still true? If so, what specifically are the circumstances under which it is not called when one might expect that it would be? 回答1: It's not that it won't be called, it's that there already is

Is it possible to override a method at runtime?

由 三世轮回 提交于 2019-12-04 03:08:47
问题 Is there anyway to override a method at run time? Even if it requires dynamically creating a subclass from that instance? 回答1: With plain Java, no. With ByteBuddy(preferred), asm, cglib or aspectj, yes. In plain Java, the thing to do in a situation like that is to create an interface-based proxy that handles the method invocation and delegates to the original object (or not). 回答2: You could create an anonymous class that overrides the method and uses the strategy pattern to decide what to do.

Hide virtual function with non-virtual override

由 核能气质少年 提交于 2019-12-04 02:59:27
问题 Having #include <iostream> using namespace std; class A { public: virtual void foo() { cout << "A" << endl; } }; class B : public A { public: void foo() { cout << "B" << endl; } }; class C : public B { public: void foo() { cout << "C" << endl; } }; int main() { C c; B* b = &c; b->foo(); return 0; } The output is C , but I expected B . I didn't declare B::foo() with the virtual modifier, so I expect the function call to be determined by the static type (no polymorphism). Why is C::foo() being

In java, Can we override a method by passing subclass of the parameter used in super class method?

由 天涯浪子 提交于 2019-12-04 02:57:54
问题 As per the rule, while overriding a method in subclass, parameters cannot be changed and have to be the same as in the super class. What if we pass subclass of parameter while overriding method ? Will it be called as overloading or overriding? Based on my query I have written some code below. I was expecting the output as "Dog eats Flesh Food" but to my surprise the output is "Animal eats Flesh Food" Will appreciate if someone can explain how does Animal method gets called when the object

How to override a generic method

由 回眸只為那壹抹淺笑 提交于 2019-12-04 02:50:37
问题 Generic method : public <T> void foo(T t); Desired overridden method : public void foo(MyType t); What is the java syntax to achieve this? 回答1: A better design is. interface Generic<T> { void foo(T t); } class Impl implements Generic<MyType> { @Override public void foo(MyType t) { } } 回答2: You might want to do something like this : abstract class Parent { public abstract <T extends Object> void foo(T t); } public class Implementor extends Parent { @Override public <MyType> void foo(MyType t)

Is it possible to override a native method in a Java class in Android/dalvik?

由 只谈情不闲聊 提交于 2019-12-04 02:46:16
I am unit testing a class TestMe using EasyMock, and one of its methods (say method(N n) ) expects a parameter of type N which has a native method (say nativeMethod() ). class TestMe { void method(N n) { // Do stuff n.nativeMethod(); // Do more stuff } } method() needs to invoke N.nativeMethod() at some point, and the problem I'm having is that my Easymock mock object for N is unable to override the native method. I do not own class N but I can refactor TestMe in any way necessary. I decided to make my own class FakeN extends N which overrides nativeMethod to do nothing: class FakeN extends N

Turn off CSS property

由 狂风中的少年 提交于 2019-12-04 02:31:26
Lets say I have a plugin's CSS which loads later as my style.css /*style.css*/ .something { position:absolute; left: 0px !important; } /*plugin's CSS*/ .something { position:absolute; left: -50px; } / now it has 0px but i want no left value at all / i know i can set !important so that property wont be overriden, but is there any solution to turn "left" off as Chrome DevTools uncheck a property? As far as I am aware (someone please feel free to correct me) there is no way to directly "turn off" a CSS property like in the Chrome DevTools. The closest you can get it to reset the property to its

Determine if Equals() is an override?

由 北城余情 提交于 2019-12-04 01:42:31
问题 I have an instance of Type (type). How can I determine if it overrides Equals()? 回答1: private static bool IsObjectEqualsMethod(MethodInfo m) { return m.Name == "Equals" && m.GetBaseDefinition().DeclaringType.Equals(typeof(object)); } public static bool OverridesEqualsMethod(this Type type) { var equalsMethod = type.GetMethods() .Single(IsObjectEqualsMethod); return !equalsMethod.DeclaringType.Equals(typeof(object)); } Note that this reveals whether object.Equals has been overridden anywhere

Override core jQuery functions on Element level

由 孤街浪徒 提交于 2019-12-04 01:41:01
Is it possible to override core jQuery functions on Element level, so for an example, i want to override val() function only on one <select> element. if i do something like this var element = $('select'); var old_val = element.val; element.val = function () { console.log('The new val'); return old_val.apply(this, arguments); } element.val(19); it works as expected, but as soon as i address the same field with new jQuery instance var element = $('select'); element.val(19); it stops working because we have new instance of jQuery object. if i fiddle with $.fn.val function i change that behavior
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