JFrame没有显示按钮或文本

-1

目前我的JFrame没有显示任何按钮，文本等。我查看了其他主题，导致错误的原因之一是因为setVisable方法在所有内容之前被调用被创建。正如你所看到的，这不是问题，因为它是在创建完成之后调用的。我的目标是底部面板有一个启动按钮，点击时JLabel取代它。（这是我的第一个swing应用程序..）JFrame没有显示按钮或文本

我的问题是，启动JButton和bottomPanel没有显示。

这是发生问题，客户端类

private void createPanel() { 
    bottomPanel = new JPanel(new BorderLayout()); 
    Launch = new JButton(Settings.launch); 
    Loading = new JLabel(Settings.loaderIcon); 
    Launch.addActionListener(this); 
} 

private void addPanel() { 
    setTitle("RuneRebellionV2 Launcher"); 
    setContentPane(new JLabel(Settings.background)); 
    getContentPane().add(bottomPanel, BorderLayout.SOUTH); 
    bottomPanel.add(new JLabel("Launcher, release " + Settings.version), BorderLayout.WEST); 
    bottomPanel.setBackground(Color.black); 
    bottomPanel.add(Launch, BorderLayout.EAST); 
    Launch.setPreferredSize(new Dimension(120, 40)); 
    setSize(Settings.width, Settings.height); 
    add(bottomPanel); 
}

这是系统的其余部分它的工作原理是这样..你启动开始。

package com.RBV2; 

import java.io.IOException; 

import com.RBV2.engine.Client; 
/* 
* Author David 
* 
*/ 
public class Initiate { 
    public static void main(String[] args) { 
     try { 
      Settings.init(); 
      Client.main(args); 
      System.out.println("Client started. -Alpha"); 
     } catch (IOException e) { 
      e.printStackTrace(); 
     } 
    } 
}

运行Settings.java

package com.RBV2; 

import java.net.MalformedURLException; 
import java.net.URL; 

import javax.swing.Icon; 
import javax.swing.ImageIcon; 

/* 
* Author David 
* 
*/ 

public class Settings { 
    public static String version = "1.0.0"; 
    public static String saveDirectory = System.getProperty("user.home")+"/"; 

    public static ImageIcon launch; 
    public static ImageIcon icon1; 
    public static ImageIcon icon2; 
    public static Icon loaderIcon; 
    public static ImageIcon slideshow; 
    public static ImageIcon background; 

    public static int width = 800, height = 480; 

    public static String downloadUrl = "http://www.runerebellion.com/RuneRebellion.jar"; 
    public static String fileName = "RuneRebellion.jar"; 
    public static String serverName = "RuneRebellion"; 

    public static void init() {//Have to host files online 
     try { 
      URL background = new URL("http://www.runerebellion.com/clientImages/background.png"); 
      Settings.background = new ImageIcon(background); 
      URL slideshow = new URL("http://www.runerebellion.com/clientImages/launch.png");//temp 
      Settings.slideshow = new ImageIcon(slideshow); 
      URL loaderIcon = new URL("http://www.runerebellion.com/clientImages/loader.gif"); 
      Settings.loaderIcon = new ImageIcon(loaderIcon); 
      URL icon2 = new URL("http://www.runerebellion.com/clientImages/testcommunity.png"); 
      Settings.icon2 = new ImageIcon(icon2); 
      URL icon1 = new URL("http://www.runerebellion.com/clientImages/community.png"); 
      Settings.icon1 = new ImageIcon(icon1); 
      URL launch = new URL("http://www.runerebellion.com/clientImages/launch.png"); 
      Settings.launch = new ImageIcon(launch); 
     } catch (MalformedURLException e) { 
      e.printStackTrace(); 
     } 
    } 
}

然后这个类使用设置，使JFrame中。

package com.RBV2.engine; 

import javax.swing.*; 
import javax.swing.text.html.HTMLEditorKit; 

import com.RBV2.Settings; 

import java.awt.*; 
import java.awt.event.ActionEvent; 
import java.awt.event.ActionListener; 
import java.io.File; 
import java.io.IOException; 
import java.net.URL; 
import java.net.URLConnection; 

import java.io.*; 
/* 
* Author Jon & David 
* 
*/ 
@SuppressWarnings("serial") 
public class Client extends JFrame implements ActionListener { 
    private JPanel bottomPanel; 
    private JButton Launch; 
    private JLabel Loading; 
    //private JLabel Loading = new JLabel(Settings.loaderIcon); 

    protected boolean updated = false; 

    public void refresh() { 
     setSize(Settings.width - 1, Settings.height - 1); 
     setSize(Settings.width, Settings.height); 
    } 

    private void createLayout() { 
     createPanel(); 
     addPanel(); 
     setVisible(true); 
    } 

    private void createPanel() { 
     bottomPanel = new JPanel(new BorderLayout()); 
     Launch = new JButton(Settings.launch); 
     Loading = new JLabel(Settings.loaderIcon); 
     Launch.addActionListener(this); 
    } 

    private void addPanel() { 
     setTitle("RuneRebellionV2 Launcher"); 
     setContentPane(new JLabel(Settings.background)); 
     getContentPane().add(bottomPanel, BorderLayout.SOUTH); 
     bottomPanel.add(new JLabel("Launcher, release " + Settings.version), BorderLayout.WEST); 
     bottomPanel.setBackground(Color.black); 
     bottomPanel.add(Launch, BorderLayout.EAST); 
     Launch.setPreferredSize(new Dimension(120, 40)); 
     setSize(Settings.width, Settings.height); 
     add(bottomPanel); 
    } 

    private void checkUpdates() { 
     try { 
     final URL url = new URL(Settings.downloadUrl); 
     URLConnection connection = url.openConnection(); 
     connection.connect(); 
     downloadUpdates(url); 
     } catch(IOException e) {//failed to connect therefore lets just run the client if it exists all will run smooth 
      try { 
       startApplication(); 
      } catch (InterruptedException e1) { 
       e1.printStackTrace(); 
      } 
     } 
    } 

    private void downloadUpdates(final URL url) {//Downloads the client off the website & removes older client 
     try { 
      final File file = new File(Settings.saveDirectory + url.getFile()); 
      if (file.exists()) 
       file.delete(); 

      Thread t = new Thread() { 
       public void run() { 
        try { 
         OutputStream dest = new BufferedOutputStream(
           new FileOutputStream(file)); 
         URLConnection download = url.openConnection(); 
         InputStream readFileToDownload = download 
           .getInputStream(); 
         byte[] data = new byte[1024]; 
         int numRead; 
         download.getContentLength(); 
         while ((numRead = readFileToDownload.read(data)) != -1) { 
          dest.write(data, 0, numRead); 
         } 
         if (readFileToDownload != null) 
          readFileToDownload.close(); 
         if (dest != null) 
          dest.close(); 
         Thread.sleep(1000L); 
         startApplication(); 
        } catch (IOException | InterruptedException e) { 
         e.printStackTrace(); 
        } 
       } 
      }; 
      t.start(); 
     } catch (Exception e) { 
      e.printStackTrace(); 
     } 
    } 

    public Client() throws IOException { 
     createLayout(); 
    } 

    public void actionPerformed(ActionEvent e) { 
     if (e.getSource() == Launch) { 
      checkUpdates(); 
     } 
    } 

    public static void startApplication() throws InterruptedException { 
     try { 
      Runtime.getRuntime().exec(
        "java -jar " + (Settings.saveDirectory + Settings.fileName) 
          + ""); 
      Thread.sleep(1000L); 
      System.exit(0); 
     } catch (IOException e) { 
      e.printStackTrace(); 
     } 
    } 

    public static void main(String args[]) throws IOException { 
     final Client l = new Client(); 
     l.setVisible(true); 
     SwingUtilities.invokeLater(new Runnable() { 
      public void run() { 
       l.setVisible(true); 
      } 
     }); 

    } 

}

编辑：

setContentPane(new JLabel(Settings.background));

替换

JLabel label = new JLabel(Settings.background); 
setContentPane(label); 
label.setLayout(new BorderLayout());

修正了问题，由于被放置在一切的JLabel。

来源

2014-02-09 RuneRebellion

你的代码有点复杂，或者我认为编程术语是它有很多“[复杂性]（http://en.wikipedia.org/wiki/Cyclomatic_complexity）”。这会让你和其他人难以调试它。考虑重构，简化和避免许多副作用的方法。 –

@HovercraftFullOfEels真的只有一点需要看，我把这段代码分开了..我真的不明白你的意思，但我可以完美地阅读代码。 – RuneRebellion

你可以阅读代码，但你找不到错误，对不对？否则你不会在这里。但我的意思是说，你的许多方法改变了类字段的状态并且什么都不返回，这会增加复杂性，因为它不太明显，它们如何改变状态，从而可能导致问题。 –

这里的问题

setContentPane(new JLabel(Settings.background));

你设置与标签内容窗格中。如果你摆脱这一点，它的作品。

一个选项，如果你想有一个背景图片，是把它漆成上JPanel像这样

public class ButtonPanel extends JPanel { 

    Image img; 

    public ButtonPanel() { 
     img = (Settings.background).getImage(); 
    } 

    @Override 
    protected void paintComponent(Graphics g) { 
     super.paintComponent(g); 
     g.drawImage(img, 0, 0, getWidth(), getHeight(), this); 
    } 

    @Override 
    public Dimension getPreferredSize() { 
     return new Dimension(Settings.width, Settings.height); 

    } 
}

的ButtonPanel将是buttonPanel您当前使用

另一种解决方案，为@MadProgrammer建议只是将背景标签的布局管理器设置为BorderLayout，像这样

private void addPanel() { 
    setTitle("RuneRebellionV2 Launcher"); 
    JLabel label = new JLabel(Settings.background); 
    setContentPane(label); 
    label.setLayout(new BorderLayout());

来源

2014-02-09 03:17:47

或设置标签的布局管理器.... – MadProgrammer

对不起，意思是给你+1，但我2岁的女儿决定她需要做一些“computr”工作...：P – MadProgrammer

@MadPogrammer aww有多可爱;）..我会添加你的建议，虽然+1回atcha！ –

JFrame没有显示按钮或文本

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