methods

问题 Given the following code: import javax.swing.*; import java.awt.*; public class NewClass extends JPanel { public void paintComponent(Graphics g) { g.drawLine(0, 0, 90, 90); } public static void main(String[] args) { JFrame jf = new JFrame(); jf.add(new NewClass()); jf.setSize(500, 500); jf.setVisible(true); } } Why does it draw a line if the method drawLine is abstract and, as I managed to understand, an abstract method has no definition? Thank you in advance! 回答1: paintComponent() gets a non

问题 My Web view is not calling the javascript function it is returning warning like below. Can anybody suggest how to get rid of the below warning. 07-30 10:15:44.031: W/webview_proxy(3770): java.lang.Throwable: Warning: A WebView method was called on thread 'WebViewCoreThread'. All WebView methods must be called on the UI thread. Future versions of WebView may not support use on other threads. Below is my function. public boolean onLongClick(View v){ System.out.println("dfdsf"); // Tell the

问题 My Web view is not calling the javascript function it is returning warning like below. Can anybody suggest how to get rid of the below warning. 07-30 10:15:44.031: W/webview_proxy(3770): java.lang.Throwable: Warning: A WebView method was called on thread 'WebViewCoreThread'. All WebView methods must be called on the UI thread. Future versions of WebView may not support use on other threads. Below is my function. public boolean onLongClick(View v){ System.out.println("dfdsf"); // Tell the

问题 The Principle Engineer at my last company had a rule that private static methods should be implemented as functions in the implementation file, not as class methods. I don't remember if there were any exceptions to his rule. I have stumbled into the motivation for it at my current job: If the arguments or return type of the function in question are objects that would require the inclusion of a definition file in the header, this can cause unnecessary difficulties. That's enough to steer me

问题 What is the difference between calling the methods with following types 1. [self methodName]; and 2. [self performSelector:@selector(methodName)]; // no afterDelay is used Is it like performSelector will use different thread to work?? 回答1: In most cases, they are equivalent. According to the documentation, the purpose of the performSelector: variant is so that you can call methods that are defined dynamically and not actually present at compile-time. That's all. For calling a method that is

问题 This seems like it should be fairly straight-forward, but I can't see anything obvious. What I basically want to do it to point at a method and refactor->extract class. This would take the method in question to a new class with that method as top level public API. The refactoring would also drag any required methods and variables along with it to the new class, deleting them from the old class if nothing else in the old class is using it. This is a repetitive task I often encounter when

问题 so im just trying to print a random word and thats it Dictionary secret = new Dictionary(); secret.getRandomWord(); System.out.println(secret); ^all that is in my main program. And what was given to me that i have to use public String getRandomWord(){ Random generator = new Random(); String temp = new String(); temp += dictionary[generator.nextInt(NUMBER_OF_WORDS)]; return temp; the above code is a class that was given to me that i have to work with. when i run my code i get program3

问题 I'm trying to render a list of notes and in that list I would like to include the note's user name based on the user_id stored in the note's table. I have something like this, but at the moment it is logging an error stating Cannot read property 'user_id' of undefined , which I get why. My question is, in Vue how can something like this be executed? Template: <div v-for="note in notes"> <h2>{{note.title}}</h2> <em>{{user.name}}</em> </div> Scripts: methods:{ fetchNotes(id){ return this.$http

问题 I'm using classes here to input a fraction (when given the numerator and denominator), as well as add and multiply two fractions together. For some reason, the imported fractions module only works correctly for part of the program; the gcd method works, but the Fraction method (where when given two numbers, puts into fraction format) does not work, instead throwing a NameError (specifically, "global name 'Fractions' is not defined"). What am I doing wrong? I am relatively new to Python, and

问题 If one does something on the client like Foo.insert({blah : 1}) where Foo is a Meteor collection, this actually triggers a Meteor.method call as documented in the last paragraph of http://docs.meteor.com/#meteor_methods that executes code on both the client and the server. However, let's say I define a method (on client and server) that does the same thing: Meteor.methods({ bar: function() { Foo.insert({blah : 1}) } }); Now, I trigger this on the client with Meteor.call("bar"); Foo.insert