overriding

问题 I'm trying to override the vector class and add a custom function to it, but coming from Java I'm not really familiar with the mechanics of overriding, inheriting and that kind of stuff. 回答1: The standard containers aren't polymorphic, so you can't override their behaviour; and have no protected members so there's no point inheriting from them to extend them. While you could do that, as suggested by another answer, you would have to reimplement all the constructors (or, since 2011, explicitly

问题 I have a decent understanding about polymorphism but my question is for example, in the code I posted below, what is so special about being able to make an object of Cat while using an animal type for the variable. What purpose does that serve? Also assume that the makenoise method is being override in each objects own class and that the class all the other classes are inheriting from is the animal class. public class Demo { public static void main(String[] args) { Animal a1 = new Cat(); /

问题 I am using Dialog components from material-ui ReactJs. <Dialog fullScreen open={this.state.open} PaperProps={{ classes: {root: classes.dialogPaper} }} onClose={this.handleClose.bind(this)} transition={this.props.transition}> {this.props.children} </Dialog> In the above code I already override the root classes of PaperProps. Now I also want to override the style in the PaperProps. Is that possible in the PaperProps to override the styles. Something like PaperProps={{ classes: {root: classes

问题 When I tried to understand how to work with collections in java, I realised that I don't understand how polymorphism works for inner classes. Simple code example: class Parent { public static void main(String[] args) { new Parent().newInnerClass().myMethod(); new Child().newInnerClass().myMethod(); } public I newInnerClass() { return new InnerClass(); } private final class InnerClass implements I { @Override public void myMethod() { System.out.println("parent inner class"); foo(); } } public

问题 I have a custom class which I derived from the UIView class. What I want to accomplish is just drawing vertical black lines with a predefined distance between. When I override the drawRect method and write my code to draw vertical lines, the view just shows a complete black background. Then I noticed that even an empty overridden drawRect which only calls the superclass' drawRect results in a black background. When I comment out the drawRect, then the view shows through and becomes

问题 I've read some stuff about overriding Equal and GetHashcode but do I need it when just having a simple own Equal method like below? And if I do have to override it: Why is that? - Should I use Id.GetHashCode() when overriding GetHashCode()? public class Foo { public Guid Id { get; } = new Guid(); public bool Equal(Foo other) { if (other == null) return false; return Id == other.Id; } } 回答1: Your code looks like you want to implement IEquatable<Foo> for your object. And MSDN advice to oveeride

问题 I have just overide my back button in my code like this @Override public boolean onKeyDown(int keyCode, KeyEvent event) { if (keyCode == KeyEvent.KEYCODE_BACK) { return true; } return super.onKeyDown(keyCode, event); } @Override public boolean onKeyUp(int keyCode, KeyEvent event) { { startActivity(new Intent(context, MainDialog.class)); finish(); return true; } return super.onKeyUp(keyCode, event); } Now I am facing a weird problem, I have a edit text on the current Activity. At the time of

问题 I have site which uses $(selector).load(path) function in more than 300 pages. Now my client's requirement has changed and I need to access cross domain to call these pages. For the purpose I have to replace all the .load( function to some cross-domain function with the help of YQL. Is it possible to override my .load function and call prevent default and do my own code? 回答1: There is no clean way to do this, especially since $.fn.load does different things depending on the arguments and

问题 I have '-Wredundant-decls' in my CXXFLAGS but for one file, I want it removed. In my GNU makefile, how can I structure a rule to remove just that part of the CXXFLAGS. I know how to add only for that file, I would do something like this: $O/just_one_file.o: CXXFLAGS += -Wredundant-decls So, ideally I'd do something like this (which doesn't work) to remove it: $O/just_one_file.o: CXXFLAGS -= -Wredundant-decls However, maybe with some $ magic, I can construct some kind of sed or perl script to

问题 I have '-Wredundant-decls' in my CXXFLAGS but for one file, I want it removed. In my GNU makefile, how can I structure a rule to remove just that part of the CXXFLAGS. I know how to add only for that file, I would do something like this: $O/just_one_file.o: CXXFLAGS += -Wredundant-decls So, ideally I'd do something like this (which doesn't work) to remove it: $O/just_one_file.o: CXXFLAGS -= -Wredundant-decls However, maybe with some $ magic, I can construct some kind of sed or perl script to