subclass

问题 I am a beginner, taking a CompSci class in school. This chapter is making subclasses; however, The class is somehow causing the program to terminate. The world doesn't even appear, and there are no errors. (I am running Eclipse). Here is my code: package karel; import kareltherobot.*; public class Race implements Directions { public static void main(String args[]) { class Car extends UrRobot { public Car(int street, int avenue, Direction direction, int beepers) {super(5, 5, East, infinity); }

问题 I would like to roughly monitor the progress of a file upload. I know that I can override the MultipartEntity and make the writeTo(OutputStream out) method write to a FilterOutputStream class that I created to wrap the default InputStream. For full details on how I did that, see my answer here. However, upon closer inspection this counts every byte sent twice! I went to the documentation to see what was up. Looks like FilterOutputStream's write(byte[], int, int) method simply calls the

问题 I have been trying to adapt the code from the accelerometer example such that when the user depresses a uibutton a point is added to a line graph. Working on the converting two floats, which are the result of calculate as below into a CGPoint and converting the CGPoint into an NSValue and then adding this to a NSMutableArray with the following -(IBAction)calculate:(id)sender { self.points = [NSMutableArray array]; CGPoint pt = CGPointMake(d, c); [self.points addObject:[NSValue

问题 I have a <mx:Script> on the main file, where I define this: [Bindable] private var dpCols:ArrayCollection = new ArrayCollection([ {'prx':'bl', 'nmb':'Blanco', 'ral':'RAL1013', 'hex':'E8E4CD'}, {'prx':'am', 'nmb':'Amarillo', 'ral':'RAL1005', 'hex':'C79E03'}, {'prx':'gr', 'nmb':'Gris Perla', 'ral':'RAL7045', 'hex':'8E939E'} ]); I can use it as a dataProvider in many places, but not here: <mx:TileList dataProvider="{dpCols}"> <mx:itemRenderer> <mx:Component> <mx:Box backgroundColor="{int('0x' +

问题 I am trying to set up FXLabel https://github.com/nicklockwood/FXLabel in my project but i get an error i cant explain. I am using Interface Builder to manage the property. .h File @property (nonatomic) IBOutlet FXLabel *titleLabel; .m File self.titleLabel.shadowColor = [UIColor colorWithWhite:1.0f alpha:0.8f]; self.titleLabel.shadowOffset = CGSizeMake(1.0f, 2.0f); self.titleLabel.shadowBlur = 1.0f; self.titleLabel.innerShadowColor = [UIColor colorWithWhite:0.0f alpha:0.8f]; self.titleLabel

问题 I would like to cite between methods inside this subclass "ImDisp", whose father class is "mywindow". But I found in "Bs" method, the 'BsInf' cannot be cited. Why? class ImDisp(mywindow): def __init__(self): super(ImDisp,self).__init__() def BsFig(self): print('BsFig') def BsInf(self): print('BsInf') def Bs(self): self.BsInf #This doesn't work, why? print('Bs') 回答1: You should call the method by adding parentheses to the function object: self.BsInf() 来源： https://stackoverflow.com/questions

问题 My code uses to classes. When the function dizzy is called it changes the color of all the lines in the uiview. What I want it to do is only change lines colors that are drawn after the function is called. It should not change the color of the lines that are already drawn like it does now. class ViewController: UIViewController { @objc func dizzy() { canvas.strokeColor = .gray } var canvas = Canvas() } class Canvas: UIView { var strokeColor = UIColor.green { didSet { self.setNeedsDisplay() }

问题 I am writing a game using the slick 2D engine and my own entity engine to work out the details of a 2D side scroller The way my code currently works is like this: Entity class holds entity information. It can have an Ability, something like Animation or sound or movement. All abilities are subclasses of an abstract class called Ability. I have a method in the Entity class where I wish to get an instance of a specific ability, so that I can use its methods: public Ability getAbility(String id)

问题 I'm facing a rather odd problem. With subclassing some NSViews, NSTableView and NSScrollView to be specific. Situation : I'm working on a quite old (ca. 7 year) project for macOS. The codebase is about 50% objc and 50% swift 3.2 and uses XIB files for the individual views. The application runs smoothly on 10.10 - 10.12 but it crashes on 10.13 pretty much instantly. The backtrace shows the following: * thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address

问题 I want to sort some team base on their points (win: 3 points, draw: 1 points and defeat: 0 points). I have an array which contains some teams' names and their results, I have extracted their scores and then sorted them descending. Here is the code I have used: import java.util.*; import java.util.Map.Entry; public class SCAN{ public static void main(String[] args) { Map<String, Integer> points = new HashMap<>(); String[] challenges = new String[]{ "Team(A) 2 - 1 Team(C)", "Team(D) 3 - 1 Team