Java 对象数组问题急问

Question

import java.awt.*;
public class  test
{
public static void main(String[] args) 
{
Button b[] = {new Button(),new Button(),new Button()};
}
}

Answer 1

import java.awt.*;
public class  test
{
public static void main(String[] args) 
{
Button b[] = new Button[10];
                  for (int i = 0; i < 10; i++) {
                          b[i] = new Button();
                  }
}
}

Answer 2

JButton[] button;
button=new JButton();

Answer 3

sorry
JButton[] button;
button=new JButton()[];

Answer 4

..............java.lang.NullPointerException..............
>??????????????????

Answer 5

to beyond_xiruo(希偌)also errortest.java:7: illegal start of expression
                b =  new Button()[];
                                  ^
test.java:7: ']' expected
                b =  new Button()[];
                                   ^
test.java:7: array required, but java.awt.Button found
                b =  new Button()[];
                                 ^
3 errors

Answer 6

test.java:7: illegal start of expression
                b =  new JButton()[];
                                   ^
test.java:7: ']' expected
                b =  new JButton()[];
                                    ^
test.java:7: array required, but javax.swing.JButton found
                b =  new JButton()[];
                                  ^

Answer 7

用HashMap实现
HashMap h;
              String ButtonName;//按钮名称，通过这个从HashMap中取出  Button对象              生成:              h.put(ButtonName,new Button());
取出：             Button a=(Button)h.get(ButtonName);

Answer 8

sorry,
JButton[] button;
button=new JButton[100];

Answer 9

写了一个动态增减按钮的例子，如下：
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;public class applet5 extends JFrame  implements ActionListener
{
JPanel contentPanel=(JPanel)this.getContentPane();
JPanel jp1=new JPanel(new FlowLayout());
JPanel jp2=new JPanel(new FlowLayout());
JButton jb1=new JButton("add");
public applet5() {
super("myJFrame");
this.setSize(400,300);
this.setResizable(false);
this.setLocation(this.getToolkit().getScreenSize().width/2-this.getWidth()/2,this.getToolkit().getScreenSize().height/2-this.getHeight()/2);
contentPanel.setLayout(new BorderLayout());
contentPanel.add("North",jp1);
contentPanel.add("Center",jp2);
jp1.add(jb1);
this.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
jb1.addActionListener(this);
this.setVisible(true);
}public void actionPerformed(ActionEvent e) {
if(e.getSource()==jb1) {
      JButton jb2=new JButton("remove_self");
      jp2.add(jb2);
      jb2.addActionListener(this);
      this.validate();
} else {
      jp2.remove((JButton)e.getSource());
      this.validate();
      jp2.repaint();
}
}public static void main(String args[]) {
    new applet5();
}
}

Answer 10

hey,这样可以通过编译JButton[] b={new JButton("first"),new JButton("second"),
new JButton("third")};

Answer 11

//Author: Leon
//This program obeyed GPL.
//ObjectArray.java
// dynamic object import java.awt.*;
import java.awt.event.*;
import javax.swing.*;public class ObjectArray extends JFrame
{
private JButton addButton;
private JButton[] b;
public ObjectArray()
{
setTitle("add button object");
setSize(300,200);
getContentPane().setLayout(new GridLayout());
addWindowListener(new WindowAdapter()
{
public void windowClosing(WindowEvent evt)
{
System.exit(0);
}
});


addButton=new JButton("Add Button");
addButton.setSize(50,30);
getContentPane().add(addButton);
addButton.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent evt)
{
b=new JButton[3];


for( int i=0;i<b.length;i++)
{
b[i]=new JButton("button"+i);
getContentPane().add(b[i]);
b[i].repaint();
}
//repaint();
}
});
}
public static void main(String[] args)
{
new ObjectArray().show();
}

}

Answer 12

我知道了 ，你button数组没有实例化
JButton[] button;
仅是声明了数组button[n]=new JButton();
实例了每个数组中的元素正确的是：
JButton[10] button=new JButton[];
试试看行吗？？
记得给我分哦！我没有分用了！