java的，油漆的JPanel，这是另一种的JPanel里面

Question

嗨 我发了火模拟器与JTextArea的 http://xieu901.webs.com/fire.jar

现在我想的JPanel或帆布代替的JTextArea，使其（只是想挑战自己^^） 我设法在一个仅在JPanel中JFrame的 绘制的图像，但我不能画在一个JPanel任何在JFrame的中另一个的JPanel

还有什么办法用绘画方法，无需扩展JComponent的？ ，我不知道如何创建一个新的Graphics对象

public class gui extends JComponent { 

    //create gui elements 
    MigLayout layout= new MigLayout("fillx,filly", "[70%,fill][30%,fill]",""); 
JLabel status = new JLabel("status"); 
JTextField sizeoffield = new JTextField(); 
JButton ok= new JButton("Start"); 
JButton reset= new JButton("Reset"); 
JButton update= new JButton("Update"); 
JPanel mainPanel = new JPanel(layout); 
JPanel panel = new JPanel();  
JFrame win = new JFrame("my win"); 

    //constructor = create gui 
    gui(){ 
    win.setVisible(true); 
    win.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
    win.setBounds(1,1,800,600); 
    panel.setPreferredSize(panel.getMaximumSize());//wichtig 
    win.add(mainPanel); 

    mainPanel.add(panel,"spany 4,align left,aligny top"); 
mainPanel.add(sizeoffield,"wrap"); 
    mainPanel.add(ok,"wrap,aligny t"); 
    mainPanel.add(reset,"wrap,aligny t"); 
    mainPanel.add(update,"wrap,aligny t"); 
    mainPanel.add(status); 


    panel.addMouseListener(mouse); 
    ok.addActionListener(listener); 
    reset.addActionListener(listener); 
    update.addActionListener(listener); 
} 
    /*******a long code of mouse/actionlistener and other methods was cut here *******/ 

//load imageicon to convert to image later 
private ImageIcon loadImage(String s) { 
    java.net.URL imgURL = gui.class.getResource(s); 
    return new ImageIcon(imgURL); 
} 

public void paint(Graphics g) { 
    Graphics2D g2d = (Graphics2D) g; 
    g2d.drawString("Java 2D", 50, 50); 
    g2d.drawRoundRect(1, 1, 100, 100, 100, 100); 
    g2d.setColor(Color.black); 
    g2d.fillRect(0, 0, this.getWidth(), this.getHeight()); 
    g2d.drawImage(fire,1,1,50,50,null); 
} 


@Override 
public void repaint() { 
    super.repaint(); 
} 

public static void main(String[] args) { 
    new gui(); 
} 
} 

与上面的代码我有一个正常的JPanel（这应该是黑色的，所以我想用paint方法wasnt）

这里是我的代码是JFrame中的JPanel，它可以工作

package jpanel; 
import java.awt.Color; 
import java.awt.Graphics; 
import java.awt.Graphics2D; 
import java.awt.Image; 

import javax.swing.ImageIcon; 
import javax.swing.JComponent; 
import javax.swing.JFrame; 

public class Panel extends JComponent{ //class Panel 
    ImageIcon fireicon = loadImage("regen.png"); 
    ImageIcon normalicon = loadImage("regen.png"); 
    ImageIcon regenicon = loadImage("regen.png"); 
    Image fire= fireicon.getImage(); 
    Image normal= normalicon.getImage(); 
    Image regen= regenicon.getImage(); 

private ImageIcon loadImage(String s) { 
    java.net.URL imgURL = gui.class.getResource(s); 
    return new ImageIcon(imgURL); 
} 


    public void paint(Graphics g) { 
    Graphics2D g2d = (Graphics2D) g; 
    g2d.drawString("Java 2D", 50, 50); 
    g2d.drawRoundRect(1, 1, 100, 100, 100, 100); 
    g2d.setColor(Color.black); 
    g2d.fillRect(0, 0, this.getWidth(), this.getHeight()); 
    g2d.drawImage(fire,1,1,50,50,null); 
} 


// @Override 
// public void repaint() { 
// super.repaint(); 
// } 

public static void main(String[] args) { 
    JFrame win = new JFrame(); 
    win.add(new Panel()); 
    win.setVisible(true); 
    win.setSize(400, 400); 
} 
} 

Answer 1

不，GUI的图形是由swing创建的。这个例子的工作原理，并可能给你一个提示：

public static void main(String... args) { 
    JFrame frame = new JFrame("Test"); 

    JPanel outer = new JPanel(new GridLayout(1, 1)); 
    JPanel inner = new JPanel(new GridLayout(1, 1)); 
    MyComponent component = new MyComponent(); 

    frame.add(outer, BorderLayout.CENTER); 
    outer.add(inner); 
    inner.add(component); 

    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
    frame.setSize(400, 300); 
    frame.setVisible(true); 
} 

static class MyComponent extends JComponent { 

    @Override 
    protected void paintComponent(Graphics g) { 
     super.paintComponent(g); 

     g.setColor(Color.BLACK); 
     Rectangle r = getBounds(); 
     g.drawRect(r.x + 10, r.y + 10, r.width - 20, r.height - 20); 
    } 
} 

Answer 2

感谢dacwe， 代码帮助了我，现在我就可以开始真正的工作^^

package nad; 

import java.awt.Color; 
import java.awt.Graphics; 
import java.awt.Graphics2D; 
import java.awt.GridLayout; 
import java.awt.Image; 

import javax.swing.ImageIcon; 
import javax.swing.JButton; 
import javax.swing.JComponent; 
import javax.swing.JFrame; 
import javax.swing.JPanel; 

import jpanel.gui; 

import net.miginfocom.swing.MigLayout; 

    class Componentprobe extends JComponent{ 

    ImageIcon fireicon = loadImage("regen.png"); 
    Image fire= fireicon.getImage(); 

    private ImageIcon loadImage(String s) { 
      java.net.URL imgURL = gui.class.getResource(s); 
      return new ImageIcon(imgURL); 
    } 

    protected void paintComponent(Graphics g) { 
//  super.paintComponent(g); 
// 
//  g.setColor(Color.BLACK); 
//  Rectangle r = getBounds(); 
//  g.drawRect(r.x + 10, r.y + 10, r.width - 20, r.height - 20); 

     Graphics2D g2d = (Graphics2D) g; 
     g2d.drawString("Java 2D", 50, 50); 
     g2d.drawRoundRect(1, 1, 100, 100, 100, 100); 
     g2d.setColor(Color.black); 
     g2d.fillRect(0, 0, this.getWidth(), this.getHeight()); 
     for (int i = 0; i < 10; i++) { 
      for (int j = 0; j < 10; j++) { 
       g2d.drawImage(fire,1+i*50,1+j*50,50,50,null); 
      } 
     } 

    } 
    public static void main(String[] args) { 
     JButton button1= new JButton("OK"); 
     JButton button2= new JButton("reset"); 
     JButton button3= new JButton("update"); 

     MigLayout layout= new MigLayout("fillx,filly", "[70%,fill][30%,fill]",""); 
     Componentprobe component = new Componentprobe(); 
     JPanel panel = new JPanel(new GridLayout(1, 1)); //Miglayout or null layout wont work 
     JPanel main= new JPanel(layout); 
     JFrame win = new JFrame("component probe"); 


     win.setVisible(true); 
     win.setSize(400, 400); 

     win.add(main); 
     main.add(panel,"spany 3,aligny top,align left"); 
     panel.setPreferredSize(panel.getMaximumSize());//wichtig 
     panel.add(component); 


     main.add(button1,"wrap,aligny top"); 
     main.add(button2,"wrap,aligny top"); 
     main.add(button3,"aligny t"); 


     win.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     win.setSize(400, 300); 
     win.setVisible(true); 
    } 

}