動態創建JPanels

我正在嘗試製作一個具有JTabbedPane的GUI，並顯示RF網絡上的無線電之間的連接。我無法弄清楚如何使tabbedPanes動態創建。我嘗試了很多事情，但都沒有成功。這是我到目前爲止。動態創建JPanels

這是平局類

import javax.swing.*; 
import java.awt.*; 
import java.awt.event.*; 
import java.awt.geom.*; 

public class draw extends JPanel implements MouseListener{ 

    private Color currentColor = Color.RED; 

    //Array to hold the grid dimensions used for drawing radio[] 
    private int[] gD = {40, 100, 160, 220, 280, 340, 400, 460}; 

    //Flag for changing colors in the grid 
    private boolean colorChanged = false; 

    public void drawing() { 
     repaint(); 
    } 

    public void paintComponent(final Graphics g) { 
     super.paintComponent(g); 
     final Graphics2D g2d = (Graphics2D)g; 

     //Smooth Graphics 
     ((Graphics2D) g).setRenderingHint(RenderingHints.KEY_ANTIALIASING, 
       RenderingHints.VALUE_ANTIALIAS_ON); 

     //Quality Color Rendering 
     ((Graphics2D) g).setRenderingHint(RenderingHints.KEY_COLOR_RENDERING, 
       RenderingHints.VALUE_COLOR_RENDER_QUALITY); 

     //Array to hold 40 radios 
     final Ellipse2D.Double radio[] = new Ellipse2D.Double[39]; 

     //Array to hold lines that show radio connections 
     final Line2D connection[] = new Line2D[49]; 

     /**************************************************************** 
     This section of code draws the Ellipses that represent the 
     different radios. 
     *****************************************************************/ 
     radio[0] = new Ellipse2D.Double(gD[2], gD[0], gD[0], gD[0]); 
     g2d.setPaint(currentColor); 
     g2d.fill(radio[0]); 
     this.addMouseListener(this); 

     radio[1] = new Ellipse2D.Double(gD[1], gD[1], gD[0], gD[0]); 
     g2d.setPaint(currentColor); 
     g2d.fill(radio[1]); 
     this.addMouseListener(this); 

     radio[2] = new Ellipse2D.Double(gD[0], gD[2], gD[0], gD[0]); 
     g2d.setPaint(currentColor); 
     g2d.fill(radio[2]); 
     this.addMouseListener(this); 

     radio[3] = new Ellipse2D.Double(gD[1], gD[3], gD[0], gD[0]); 
     g2d.setPaint(currentColor); 
     g2d.fill(radio[3]); 
     this.addMouseListener(this); 

     radio[4] = new Ellipse2D.Double(gD[2], gD[4], gD[0], gD[0]); 
     g2d.setPaint(currentColor); 
     g2d.fill(radio[4]); 
     this.addMouseListener(this); 

     radio[5] = new Ellipse2D.Double(gD[5], gD[0], gD[0], gD[0]); 
     g2d.setPaint(currentColor); 
     g2d.fill(radio[5]); 
     this.addMouseListener(this); 

     radio[6] = new Ellipse2D.Double(gD[6], gD[1], gD[0], gD[0]); 
     g2d.setPaint(currentColor); 
     g2d.fill(radio[6]); 
     this.addMouseListener(this); 

     radio[7] = new Ellipse2D.Double(gD[7], gD[2], gD[0], gD[0]); 
     g2d.setPaint(currentColor); 
     g2d.fill(radio[7]); 
     this.addMouseListener(this); 

     radio[8] = new Ellipse2D.Double(gD[6], gD[3], gD[0], gD[0]); 
     g2d.setPaint(currentColor); 
     g2d.fill(radio[8]); 
     this.addMouseListener(this); 

     radio[9] = new Ellipse2D.Double(gD[5], gD[4], gD[0], gD[0]); 
     g2d.setPaint(currentColor); 
     g2d.fill(radio[9]); 
     this.addMouseListener(this); 

     /**************************************************************** 
     This section of code draws the lines that represent the 
     connections to the different radios. 
     *****************************************************************/ 
     connection[0] = new Line2D.Double(radio[0].getCenterX(), radio[0].getCenterY(), radio[9].getCenterX(), radio[9].getCenterY()); 
     g2d.draw(connection[0]); 

     addMouseListener(new MouseAdapter() { 
      @Override 
      public void mouseClicked(MouseEvent e) { 

       /************************************************************************** 
       This block of statements changes the radio buttons to green when clicked 
       and sets the colorChanged flag to true. 
       *************************************************************************/ 
       if (!colorChanged && radio[0].contains(e.getX(), e.getY())) { 
        e.getSource(); 
        currentColor = Color.GREEN; 
        colorChanged = true; 
        repaint(gD[2], gD[0], gD[0], gD[0]); 
       } else if (!colorChanged && radio[1].contains(e.getX(), e.getY())) { 
        e.getSource(); 
        currentColor = Color.GREEN; 
        colorChanged = true; 
        repaint(gD[1], gD[1], gD[0], gD[0]); 
       } else if (!colorChanged && radio[2].contains(e.getX(), e.getY())) { 
        e.getSource(); 
        currentColor = Color.GREEN; 
        colorChanged = true; 
        repaint(gD[0], gD[2], gD[0], gD[0]); 
       } else if (!colorChanged && radio[3].contains(e.getX(), e.getY())) { 
        e.getSource(); 
        currentColor = Color.GREEN; 
        colorChanged = true; 
        repaint(gD[1], gD[3], gD[0], gD[0]); 
       } else if (!colorChanged && radio[4].contains(e.getX(), e.getY())) { 
        e.getSource(); 
        currentColor = Color.GREEN; 
        colorChanged = true; 
        repaint(gD[2], gD[4], gD[0], gD[0]); 
       } else if (!colorChanged && radio[5].contains(e.getX(), e.getY())) { 
        e.getSource(); 
        currentColor = Color.GREEN; 
        colorChanged = true; 
        repaint(gD[5], gD[0], gD[0], gD[0]); 
       } else if (!colorChanged && radio[6].contains(e.getX(), e.getY())) { 
        e.getSource(); 
        currentColor = Color.GREEN; 
        colorChanged = true; 
        repaint(gD[6], gD[1], gD[0], gD[0]); 
       } else if (!colorChanged && radio[7].contains(e.getX(), e.getY())) { 
        e.getSource(); 
        currentColor = Color.GREEN; 
        colorChanged = true; 
        repaint(gD[7], gD[2], gD[0], gD[0]); 
       } else if (!colorChanged && radio[8].contains(e.getX(), e.getY())) { 
        e.getSource(); 
        currentColor = Color.GREEN; 
        colorChanged = true; 
        repaint(gD[6], gD[3], gD[0], gD[0]); 
       } else if (!colorChanged && radio[9].contains(e.getX(), e.getY())) { 
        e.getSource(); 
        currentColor = Color.GREEN; 
        colorChanged = true; 
        repaint(gD[5], gD[4], gD[0], gD[0]); 

       /*************************************************************************** 
       This block of statements changes the radio buttons to red when clicked 
       and sets the colorChanged flag to false 
       ***************************************************************************/ 
       } else if (colorChanged && radio[0].contains(e.getX(), e.getY())) { 
        e.getSource(); 
        currentColor = Color.RED; 
        colorChanged = false; 
        repaint(gD[0], gD[0], gD[0], gD[0]); 
       } else if (colorChanged && radio[1].contains(e.getX(), e.getY())) { 
        e.getSource(); 
        currentColor = Color.RED; 
        colorChanged = false; 
        repaint(gD[0], gD[1], gD[0], gD[0]); 
       } else if (colorChanged && radio[2].contains(e.getX(), e.getY())) { 
        e.getSource(); 
        currentColor = Color.RED; 
        colorChanged = false; 
        repaint(gD[0], gD[2], gD[0], gD[0]); 
       } else if (colorChanged && radio[3].contains(e.getX(), e.getY())) { 
        e.getSource(); 
        currentColor = Color.RED; 
        colorChanged = false; 
        repaint(gD[0], gD[3], gD[0], gD[0]); 
       } else if (colorChanged && radio[4].contains(e.getX(), e.getY())) { 
        e.getSource(); 
        currentColor = Color.RED; 
        colorChanged = false; 
        repaint(gD[0], gD[4], gD[0], gD[0]); 
       } else if (colorChanged && radio[5].contains(e.getX(), e.getY())) { 
        e.getSource(); 
        currentColor = Color.RED; 
        colorChanged = false; 
        repaint(gD[7], gD[0], gD[0], gD[0]); 
       } else if (colorChanged && radio[6].contains(e.getX(), e.getY())) { 
        e.getSource(); 
        currentColor = Color.RED; 
        colorChanged = false; 
        repaint(gD[7], gD[1], gD[0], gD[0]); 
       } else if (colorChanged && radio[7].contains(e.getX(), e.getY())) { 
        e.getSource(); 
        currentColor = Color.RED; 
        colorChanged = false; 
        repaint(gD[7], gD[2], gD[0], gD[0]); 
       } else if (colorChanged && radio[8].contains(e.getX(), e.getY())) { 
        e.getSource(); 
        currentColor = Color.RED; 
        colorChanged = false; 
        repaint(gD[7], gD[3], gD[0], gD[0]); 
       } else if (colorChanged && radio[9].contains(e.getX(), e.getY())) { 
        e.getSource(); 
        currentColor = Color.RED; 
        colorChanged = false; 
        repaint(gD[7], gD[4], gD[0], gD[0]); 
       } 
     } 
    }); 
    } 

    @Override 
    public void mouseClicked(MouseEvent e) { 

    } 

    @Override 
    public void mousePressed(MouseEvent mouseEvent) { 

    } 

    @Override 
    public void mouseReleased(MouseEvent mouseEvent) { 

    } 

    @Override 
    public void mouseEntered(MouseEvent mouseEvent) { 

    } 

    @Override 
    public void mouseExited(MouseEvent mouseEvent) { 

    } 
}

這是FrontPage中類

import javax.swing.*; 
import java.awt.*; 
import java.awt.event.ActionEvent; 
import java.awt.event.ActionListener; 
import java.lang.*; 
import javax.swing.JTabbedPane; 
import javax.swing.JPanel; 
import javax.swing.JFrame; 


public class FrontPage extends JFrame{ 

    private JPanel rootPanel; 
    private JButton buttonPushConfiguration; 
    private JTabbedPane tabbedPane; 

    public FrontPage() { 

     this.setBounds(new Rectangle(0, 0, 600, 600)); 
     setContentPane(rootPanel); 
     setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     setVisible(true); 
     draw object = new draw(); 

     //Creates the first tab 
     tabbedPane.addTab("Switch 1", object); 

     object.drawing(); 


     buttonPushConfiguration.addActionListener(new ActionListener() { 
      @Override 
      public void actionPerformed(ActionEvent e) { 
       JOptionPane.showMessageDialog(FrontPage.this, "Configuration Pushed to Panel"); 
      } 

     }); 
    } 
}

這是主類

import javax.swing.*; 

public class Main { 
    public static void main(String[] args) { 

     //Set the theme to the current system theme. 
     try { 

      UIManager.setLookAndFeel(
        UIManager.getSystemLookAndFeelClassName()); 
     } 
     catch(UnsupportedLookAndFeelException e){ 

      // handle exception 
     } 
     catch(ClassNotFoundException e){ 

      // handle exception 
     } 
     catch(InstantiationException e){ 

      // handle exception 
     } 
     catch(IllegalAccessException e){ 
     } 

     //Instantiates FrontPage 
     new FrontPage(); 

    } 
}

來源

2015-07-12 feltersnach

您正在繪畫方法（此處爲paintComponent）中添加一個MouseListener，這是您永遠不應該做的事情。當你真的只需要一個鼠標監聽器時，這可能會將許多MouseListener添加到JPanel中，這實際上是一個不可控制的量。只能在paint或paintComponent方法內繪畫，而不能僅僅繪畫。 –

Next：上面的代碼編譯時會嘗試使用未初始化的組件，但會從多個位置拋出NullPointerExceptions。請在發佈之前嘗試修復此問題。我們是志願者，如果您不會過分努力地嘗試使用您的代碼，我們將非常感激。此外，您還想擴展您的主要問題所在。你聲明你想創建JPanel，但是在哪裏，在什麼樣的刺激下？按鈕推？請再次告訴詳細信息，以幫助我們瞭解您的問題並更好地爲您提供幫助。 –

還描述了GUI應該顯示的行爲。例如，MouseListener的目的是什麼？在一個選項卡的JPanel與另一個選項卡上顯示的內容是什麼？ –

如果你的目標是增加一個新JPanel，以你的JTabbedPane在按鈕的ActionListener中，那麼這正是你需要做的，就像：

@Override 
    public void actionPerformed(ActionEvent e) { 
    // int variable for the tab title 
    tabIndex++; 
    String title = "Switch " + tabIndex; 

    // I renamed your draw class to conform to Java standards 
    DrawPanel tabComponent = new DrawPanel(); 
    tabbedPane.add(title, tabComponent); 
    }

如果您需要做更多，請告訴我們。我還必須重申，我對你的原來的崗位上做出了評論：

你畫法（這裏的paintComponent），這是你永遠不應該做的事情中添加的MouseListener。當你真的只需要一個鼠標監聽器時，這可能會將許多MouseListener添加到JPanel中，這實際上是一個不可控制的量。只能在paint或paintComponent方法內繪畫，而不能僅僅繪畫。
上面的代碼編譯時會嘗試使用未初始化的組件，但會從多個位置拋出NullPointerExceptions。請在發佈之前嘗試修復此問題。
此外，您的Ellipse2D和Line2D數組應該製作成實例字段，而不是paintComponent方法的本地。此外，您正在paintComponent中重新添加您的MouseListener超過一千萬次，而不僅僅是一次。
您似乎試圖一次解決太多問題，導致並增加錯誤的代碼。考慮更改您是如何創造這個方案 - 從簡單的開始，從第一原理出發，解決小問題的時間和孤立之一，只有把物品放在一起進入一個GUI

的MouseListener更改點顏色的示例：

import java.awt.BorderLayout; 
import java.awt.Color; 
import java.awt.Dimension; 
import java.awt.Graphics; 
import java.awt.Graphics2D; 
import java.awt.Point; 
import java.awt.RenderingHints; 
import java.awt.event.*; 
import java.awt.geom.Ellipse2D; 
import java.util.ArrayList; 
import java.util.Arrays; 
import java.util.HashMap; 
import java.util.List; 
import java.util.Map; 
import javax.swing.*; 

@SuppressWarnings("serial") 
public class DrawPanelMain extends JPanel { 

    private static final int PREF_W = 600; 
    private static final int PREF_H = PREF_W; 
    private List<Point> POINT_LIST = Arrays.asList(new Point[] { 
     new Point(160, 40), 
     new Point(100, 100), 
     new Point(40, 160), 
     new Point(100, 220), 
     new Point(160, 280), 
     new Point(340, 40), 
     new Point(400, 100), 
     new Point(460, 160), 
     new Point(400, 220), 
     new Point(340, 280) 
    }); 
    private JTabbedPane tabbedPane = new JTabbedPane(); 
    private int tabIndex = 0; 

    public DrawPanelMain() { 
     JPanel btnPanel = new JPanel(); 
     btnPanel.add(new JButton(new PushConfigAction("Push Config"))); 

     setLayout(new BorderLayout()); 
     add(tabbedPane, BorderLayout.CENTER); 
     add(btnPanel, BorderLayout.PAGE_END); 
    } 

    @Override 
    public Dimension getPreferredSize() { 
     if (isPreferredSizeSet()) { 
     return super.getPreferredSize(); 
     } 
     return new Dimension(PREF_W, PREF_H); 
    } 

    private class PushConfigAction extends AbstractAction { 
     public PushConfigAction(String name) { 
     super(name); 
     int mnemonic = (int) name.charAt(0); 
     putValue(MNEMONIC_KEY, mnemonic); 
     } 

     @Override 
     public void actionPerformed(ActionEvent e) { 
     tabIndex++; 
     String title = "Switch " + tabIndex; 
     DrawPanel2 tabComponent = new DrawPanel2(POINT_LIST); 
     tabbedPane.add(title, tabComponent); 
     } 
    } 

    private static void createAndShowGui() { 
     DrawPanelMain mainPanel = new DrawPanelMain(); 

     JFrame frame = new JFrame("DrawPanelMain"); 
     frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE); 
     frame.getContentPane().add(mainPanel); 
     frame.pack(); 
     frame.setLocationByPlatform(true); 
     frame.setVisible(true); 
    } 

    public static void main(String[] args) { 
     SwingUtilities.invokeLater(new Runnable() { 
     public void run() { 
      createAndShowGui(); 
     } 
     }); 
    } 
} 

@SuppressWarnings("serial") 
class DrawPanel2 extends JPanel { 
    private static final int OVAL_WIDTH = 40; 
    private static final Color INACTIVE_COLOR = Color.RED; 
    private static final Color ACTIVE_COLOR = Color.green; 
    private List<Point> points; 
    private List<Ellipse2D> ellipses = new ArrayList<>(); 
    private Map<Ellipse2D, Color> ellipseColorMap = new HashMap<>(); 

    public DrawPanel2(List<Point> points) { 
     this.points = points; 
     for (Point p : points) { 
     int x = p.x - OVAL_WIDTH/2; 
     int y = p.y - OVAL_WIDTH/2; 
     int w = OVAL_WIDTH; 
     int h = OVAL_WIDTH; 
     Ellipse2D ellipse = new Ellipse2D.Double(x, y, w, h); 
     ellipses.add(ellipse); 
     ellipseColorMap.put(ellipse, INACTIVE_COLOR); 
     } 

     MyMouseAdapter mListener = new MyMouseAdapter(); 
     addMouseListener(mListener); 
     addMouseMotionListener(mListener); 
    } 

    @Override 
    protected void paintComponent(Graphics g) { 
     super.paintComponent(g); 
     Graphics2D g2 = (Graphics2D) g; 
     g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, 
      RenderingHints.VALUE_ANTIALIAS_ON); 
     for (Ellipse2D ellipse : ellipses) { 
     g2.setColor(ellipseColorMap.get(ellipse)); 
     g2.fill(ellipse); 
     } 
    } 

    private class MyMouseAdapter extends MouseAdapter { 
     @Override 
     public void mousePressed(MouseEvent e) { 
     for (Ellipse2D ellipse : ellipses) { 
      if (ellipse.contains(e.getPoint())) { 
       Color c = ellipseColorMap.get(ellipse); 
       c = (c == INACTIVE_COLOR) ? ACTIVE_COLOR : INACTIVE_COLOR; 
       ellipseColorMap.put(ellipse, c); 
      } 
     } 
     repaint(); 
     } 
    } 
}

來源

2015-07-12 20:48:38

非常感謝，我現在正在處理這個問題。 – feltersnach

代碼很好，但我有一個問題。添加將所有省略號更改爲active_color的按鈕的最佳方法是什麼？ – feltersnach

動態創建JPanels

回答

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