第二个JFrame中的组件未显示 [英] Components in second JFrame not showing up

问题描述

我想通过按下JFrame中的按钮来启动另一个JFrame。
但是，如果按下按钮，它会显示JFrame，但不会显示按钮和滑块。

i want to start another JFrame from pressing a button in a JFrame. But if I press the Button it shows the JFrame but not the Buttons and Sliders in it.

public class MainMenu extends JFrame {


private JFrame klick;
private static final long serialVersionUID = 9002;


public static void main(String[] args) {

    new MainMenu();

}


public MainMenu() {
    buildGUI1();

}
public void buildGUI1() throws NullPointerException {
    setTitle("Hauptmenü");      
    setSize(800, 480);
    setLayout(new GridLayout());
    setAlwaysOnTop(false);
    setLocation((Toolkit.getDefaultToolkit().getScreenSize().width)/4, (Toolkit.getDefaultToolkit().getScreenSize().height)/4);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setResizable(false);
    setVisible(true);
    final JButton startclickbt = new JButton("Start Clicker");
    startclickbt.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            dispose();
            if(klick == null ) {
                klick =new Clicker();
                add(klick);
            }


        }
    });

    add(startclickbt);


    }

}

第二个具有完全相同的costructor.sliders和按钮不是静态的。
在按钮出现的地方，屏幕是黑色的。

The second has quite the same costructor.sliders and buttons are not static. At the places where Buttons should appear the screen is black.

希望你能帮帮我:)

编辑：

public class Clicker extends JFrame {

    private static final long serialVersionUID = 9001;
    protected JPanel panel;
    static Click j = null;
    protected JSlider jsl;
    protected JTextField tf;
    static final int CPS_MIN= 0;
    static final int CPS_MAX= 100;
    static final int CPS_INIT= 25;
    private int amount;
    private boolean visible;

    public int getDelay() {
        return Math.abs(jsl.getValue()-100);
    }
    public int getAmount() {
        return amount;
    }
    public boolean getVisible() {
        return visible;
    }
    public void setOpen(boolean visible) {
        this.visible=visible;
    }

    public Clicker(boolean visible) {

        buildGUI(visible);
        j = new Click(false).addPosition(new Point((Toolkit.getDefaultToolkit().getScreenSize().width)/2, (Toolkit.getDefaultToolkit().getScreenSize().height)/2)).addPosition(new Point(getLocation().x+1, getLocation().y+20));
        while(true) {

            j.runClicks(getDelay());
        }
    }

    public Clicker() {
        buildGUI(true);
        j = new Click(false).addPosition(new Point((Toolkit.getDefaultToolkit().getScreenSize().width)/2, (Toolkit.getDefaultToolkit().getScreenSize().height)/2)).addPosition(new Point(getLocation().x+1, getLocation().y+20));
        while(true) {

            j.runClicks(getDelay());
        }
    }
    public void buildGUI(boolean visible) {

        setTitle("Clicker");
        setSize(340, 200);
        setLayout(new GridLayout());
        setAlwaysOnTop(true);
        setLocation(0, 0);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setResizable(false);
        setVisible(visible);

        final JButton bt1 = new JButton("Schließen");
        bt1.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                System.exit(0);
            }
        });
        final JButton bt2 = new JButton("Start  ");
        bt2.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                j.setClick(true);
            }
        });
        final JButton bt3 = new JButton("Stop       ");
        bt3.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                j.setClick(false);
                JOptionPane.showMessageDialog(null, "Klicken gestoppt. Klicks: " + j.getClickAmount());
                j.setClickAmout(0);
            }
        });
        final JButton bt4 = new JButton("StartAnzahl");
        bt4.addActionListener(new ActionListener() {
            private int amount;

            public void actionPerformed(ActionEvent e) {
                String wert = tf.getText();
                try {
                    amount = Integer.parseInt(wert);
                }catch(Exception ee) {
                    JOptionPane.showMessageDialog(null,"Das war keine Zahl oder mehr als ein Integer");
                }

                j.doClick(amount);


            }
        });
        tf = new JTextField("Anzahl gewünschte Clicks max "+ Integer.MAX_VALUE, 10);
        tf.setEditable(true);


        jsl = new JSlider(JSlider.HORIZONTAL,CPS_MIN,CPS_MAX,CPS_INIT);
        jsl.setMinorTickSpacing(5);
        jsl.setMajorTickSpacing(10);
        jsl.setPaintTicks(true);
        jsl.setPaintLabels(true);

        panel = new JPanel();
        panel.addMouseMotionListener(new MouseMotionListener() {

            @Override
            public void mouseDragged(MouseEvent event) {
                j.setClick(false);  
            }

            @Override
            public void mouseMoved(MouseEvent event) {
                j.setClick(false);          
            }
        });

        panel.addKeyListener(new KeyAdapter() {

            @Override
            public void keyPressed(KeyEvent e) {
                if(e.getKeyCode() == KeyEvent.VK_F1) {
                    j.setClick(true);
                }
                if(e.getKeyCode() == KeyEvent.VK_F2) {
                    j.setClick(false);
                }
            }

        });


        add(panel);
        add(bt2);
        add(bt3);
        add(bt1);
        add(bt4);
        add(jsl);
        add(tf);

        pack();
    }

}

推荐答案

让 setVisible 你调用的最后一件事......

Make setVisible the last thing you call...

public void buildGUI1() throws NullPointerException {
    setTitle("Hauptmenü");
    setSize(800, 480);
    setLayout(new GridLayout());
    setAlwaysOnTop(false);
    setLocation((Toolkit.getDefaultToolkit().getScreenSize().width) / 4, (Toolkit.getDefaultToolkit().getScreenSize().height) / 4);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setResizable(false);
    final JButton startclickbt = new JButton("Start Clicker");
    startclickbt.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            dispose();
            if (klick == null) {
                klick = new Clicker();
                add(klick);
                // Add this when you need to add/remove components
                revalidate();
                repaint();
            }

        }
    });

    add(startclickbt);
    // Move to here
    setVisible(true);

}

另外，使用 revalidate（） 和重绘（）以鼓励容器在添加新组件时更新其布局

Also, use revalidate() and repaint() to encourage the container to update it's layout when adding new components

建议：

• 确保您的UI在EDT的上下文中启动，请参阅初始主题了解更多详情


• 避免直接从顶级容器扩展喜欢 JFrame ，而是考虑使用 JPanel 作为基础容器。这个免费提供UI到更广泛的用例，并防止你被锁定（因为你不能将帧添加到其他帧）


• 使用多个JFrame，好/坏的做法？

• Make sure your UI is started within the context of the EDT, see Initial Threads for more details
• Avoid extending directly from top level containers like JFrame and instead consider using a JPanel as you base container. This free's up you UI to a wider range of use-cases and prevents you from getting locked in (as you can't add frames to other frames)
• The Use of Multiple JFrames, Good/Bad Practice?

已更新

您有两个直接问题

1. Clicker 从 JFrame 延伸，但你是试图将它添加到另一个容器，这在Swing中是不可能的，并且会导致异常，但是......


2. 您正在使用阻止事件调度线程while（true） loop，表示Swing无法处理任何新事件，包括重绘事件

1. Clicker extends from a JFrame, but you are trying to add it to another container, this is not possible in Swing and will cause an exception, however...
2. You are blocking the Event Dispatching Thread with your while (true) loop, meaning that Swing is unable to process any new events, including repaint events

例如......

public Clicker(boolean visible) {

    buildGUI(visible);
    j = new Click(false).addPosition(new Point((Toolkit.getDefaultToolkit().getScreenSize().width) / 2, (Toolkit.getDefaultToolkit().getScreenSize().height) / 2)).addPosition(new Point(getLocation().x + 1, getLocation().y + 20));
    // This is bad
    while (true) {

        j.runClicks(getDelay());
    }
}

public Clicker() {
    buildGUI(true);
    j = new Click(false).addPosition(new Point((Toolkit.getDefaultToolkit().getScreenSize().width) / 2, (Toolkit.getDefaultToolkit().getScreenSize().height) / 2)).addPosition(new Point(getLocation().x + 1, getLocation().y + 20));
    // This is bad
    while (true) {

        j.runClicks(getDelay());
    }
}

现在，点击看起来像是UI组件，它带来了许多其他问题，但是我们没有相应的代码，因此无法发表评论。

Now, Click looks like it's UI component which brings up a bunch of other problems, but we don't have the code for that so it's impossible to comment.

直接的解决方案可能是使用：

The immediate solutions might be to use a:

• SwingWorker ，请参阅工作线程和SwingWorker 了解更多详情

• SwingWorker, see Worker Threads and SwingWorker for more details

Swing 计时器，参见如何使用Swing Timers 获取更多详细信息

Swing Timer, see How to use Swing Timers for more details

要记住的事情

• Swing（和大多数UI框架一样）是单线程的，任何阻塞这个线程的东西（比如永无止境的循环）都会阻止它处理新事件，包括paint eve nts，它会使你的应用程序看起来像是挂起，因为它有


• Swing不是线程安全的。与UI的所有交互必须在事件调度线程的上下文中进行。 SwingWorker 和Swing 计时器都提供了安全更新UI的功能。

• Swing (like most UI frameworks) is single threaded, anything which blocks this thread (like never ending loops), will prevent it from processing new events, including paint events, which will make your application look like it's "hung", because it has
• Swing is NOT thread safe. All interactions with the UI MUST be made from within the context of the Event Dispatching Thread. Both SwingWorker and Swing Timer provide the capability to update the UI safely.

这篇关于第二个JFrame中的组件未显示的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！