Question

我尝试创建JButton（r）并设置其绝对位置。我也想改变背景颜色。当我像这样插入一个新的FlowLayout时：setLayout(new FlowLayout());背景的颜色在绝对位置时不会改变。

同时删除此项时：setLayout(new FlowLayout());绝对位置在颜色不变的情况下不会发生变化。所以任何人都可以解释为什么会发生这种情况，我怎么能改变代码的方式，它们的颜色和JButton变化的绝对绝对值？

这是我的代码：

import java.awt.*;
import java.awt.event.*;
import javax.swing.event.*;
import javax.swing.*;
import java.util.Random;

public class Back extends JFrame{

    private JButton r;
    private JButton c;
    private Container container;
    public Back(){
        super("title");
        //setLayout(new FlowLayout());
        ran = new Random();
        value = nextValue();

        r=new JButton("ROLL");
        add(r,BorderLayout.SOUTH);

        thehandler hand=new thehandler(this);//konstruktori i handler merr nje instance te Background
        r.addActionListener(hand);
    }

    private class thehandler implements ActionListener{
        public void actionPerformed(ActionEvent event) {
        }
    }

    public static void main(String[] args) {
         Back  d = new Back() ;

         d.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         d.getContentPane().setBackground(Color.GREEN);
         d.setSize(700,500);

         d.setVisible(true);    
    }
}

Answer 1

我编辑了你的代码，以便编译：

import java.awt.*;
import java.awt.event.*;
import javax.swing.event.*;
import javax.swing.*;
import java.util.Random;

public class Back extends JFrame {

    private JButton r;
    private Random ran;
    private String position = BorderLayout.NORTH;
    private Container container;

    public Back() {
        super("title");
        ran = new Random();
        int value = ran.nextInt();

        r = new JButton("ROLL");
        thehandler hand = new thehandler(this);//konstruktori i handler merr     nje instance te Background
        r.addActionListener(hand);

        this.change();

    }

    private class thehandler implements ActionListener {
        private final Back back;

        public thehandler(Back back) {
            this.back = back;
        }
        public void actionPerformed(ActionEvent event) {
            back.change();
        }
    }

    private void change() {
        this.remove(r);
        String newPos = null;
        if (position.equals(BorderLayout.NORTH))
            newPos = BorderLayout.SOUTH;
        else 
            newPos = BorderLayout.NORTH;
        this.add(r, newPos);
        this.position = newPos;
        int r = ran.nextInt(255);
        int g = ran.nextInt(255);
        int b = ran.nextInt(255);
        this.getContentPane().setBackground(new Color(r, g, b));
        this.revalidate();
        this.repaint();
    }

    public static void main(String[] args) {
        Back d = new Back();

        d.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        d.setSize(700, 500);
        d.setVisible(true);
    }
}

布局将在您的程序中安排JComponents：因此注释或取消注释行＆＃34; setLayout（new FlowLayout（））;＆＃34;将移动按钮。有不同的布局，如FLowLayout，BorderLayout或GridLayout。我强烈建议你使用Layouts而不是绝对定位！

我无法重现您删除该行会改变颜色的问题。相反，我认为颜色是在＃34; d.getContentPane（）。setBackground（Color.GREEN）;＆＃34;如果你想要一种不同的颜色，你可以在这里设置一个不同的颜色！

Answer 2

var io = require('socket.io')(server);
io.on('event', function(data){});

var socketUsers = [];

io.use(sharedSession(session, {
    autoSave: true
}));

io.on('connection', function(socket) {
    socketUsers.push(socket);

    console.log('Player connected: ' + socket.id); 
    console.log('Connected players: ' + socketUsers.length);

    io.on('disconnect', function() {
        for(var i = 0; i < socketUsers.length; i++) {
            console.log(socketUsers[i].id);
            if(socketUsers[i].id == socket.id) {
                //delete socketUsers[i];
                socketUsers.splice(i);
                break;
            }
        }
        console.log(socketUsers.length + ' players online.');
    });
    io.on('chat message', function(msg){
        io.emit('chat message', msg);
        console.log('message: ' + msg);
    });
    function broadcast(key, value) {
        io.emit(key, value);
    }
});

Answer 3

我知道这可能不是您正在寻找的答案。但是把它作为推荐。如果您想要绝对位置，则需要将布局更改为

setLayout(null);

我建议你使用GridBagLayout： Oralce's documentation GridBagLayout

和帮助我很多的YouTube视频： GridBagLayout tutorial

尝试更改背景颜色和Java GUI中元素的绝对位置时出错

3 个答案: