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问一个JFame中的布局和按钮和JTable有

发布时间： 2013-01-11 11:57:35 作者： rapoo

问一个JFame中的布局和按钮和JTable问题，很实用哦！欢迎各路大神前来一游
首先，我也是刚刚学JAVA，因为学习时间还很短，所以程序中有一些小毛病经常是无解了。好了，废话到这里，下面我会贴出一串代码，因为是测试代码，主要是为了体现出这些毛病，所以“难看”了些，请见谅哈！

首先是第一个问题：在BorderLayout布局中，怎么改变某个组件的大小，在代码注释那块（我写的那个不行。。。）


package 测试JTable对界面的影响;

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;

public class test 
{
public static void main(String[] args) 
{
new f();
}
}

class f extends JFrame implements ActionListener
{
JButton east, west, north, south;
JPanel peast, pwest, pnorth, psouth;
JScrollPane jsp;
JTable table;
Object a[][];
Object name[] = {"地方", "dsf", "few", "fsfse"};

f()
{
east = new JButton("窗口变大");
east.addActionListener(this);
west = new JButton("窗口变小");
west.addActionListener(this);
north = new JButton("移除其他组件");
north.addActionListener(this);
south = new JButton("显示所有组件");
south.addActionListener(this);

a = new Object[20][4];
for(int i=0; i<20; i++)
{
a[i][0] = i;
a[i][1] = i;
a[i][2] = i;
a[i][3] = i;
}
table = new JTable(a, name);

peast = new JPanel(); 
pwest = new JPanel();
pnorth = new JPanel();
psouth = new JPanel();
jsp = new JScrollPane();
peast.add(east);
pwest.add(west);
pnorth.add(north);
psouth.add(south);

//north.setSize(100, 100);//这两条语句是不是有问题呢？
//pnorth.setSize(100, 100);//为什么按钮并没有改变大小？

add(peast, BorderLayout.EAST);
add(pwest, BorderLayout.WEST);
add(pnorth, BorderLayout.NORTH);
add(psouth, BorderLayout.SOUTH);
add(jsp, BorderLayout.CENTER);
setBounds(100, 150, 350, 350);
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}

public void actionPerformed(ActionEvent e) 
{
if(e.getSource() == east)
{
jsp = new JScrollPane(table);
this.getContentPane().remove(jsp);
this.add(jsp, BorderLayout.CENTER);
this.setBounds(100, 150, 500, 500);
this.repaint();
}
else if(e.getSource() == west)
{
jsp = new JScrollPane(table);
this.getContentPane().remove(jsp);
this.add(jsp, BorderLayout.CENTER);
this.setBounds(100, 150, 300, 300);
this.repaint();
}
else if(e.getSource() == north)
{
this.getContentPane().removeAll();
this.repaint();
this.add(pnorth, BorderLayout.NORTH);
this.add(psouth, BorderLayout.SOUTH);
}
else if(e.getSource() == south)
{
jsp = new JScrollPane(table);
this.getContentPane().removeAll();
this.add(peast, BorderLayout.EAST);
this.add(pwest, BorderLayout.WEST);
this.add(pnorth, BorderLayout.NORTH);
this.add(psouth, BorderLayout.SOUTH);
this.add(jsp, BorderLayout.CENTER); 
 
this.setBounds(100, 150, 500, 350);
this.repaint();
}
}
}


第二个问题：为什么当我多次点击south（显示所有组件）按钮时，表格并没有正确的显示出来，除非用鼠标拖动改变窗口大小或者点击窗口中的其他按钮（有改变窗体大小功能的）后，再次点击south按钮，所有组件才能正确显示出来？

第三个问题：就是east（变大）按钮和west（变小）按钮，我点击之后，为什么表格没有正确的显示出来呢？

第四个问题：类似第二个问题，当我点击north按钮（为删除多个组件）后，因为窗体没有改变大小，所以点击south按钮（显示所有组件）后，表格并没有显示出来。

请教各位大神一下，是怎么个情况呢？
[解决办法]

 public void actionPerformed(ActionEvent e) 
    {
        if(e.getSource() == east)
        {
            jsp = new JScrollPane(table);       //你在构造方法里在jframe里添加了一个空的JScrollPane jsp = new JScrollPane();
            // 你现在又重新给jsp赋值，原来的jsp还在jframe上
            this.getContentPane().remove(jsp);    //所以现在你remove jsp时 jframe是找不到新的jsp的 也就是说原来的空JScrollPane还在，
            //所以会有一个空的滚动条显示在表格之上 ，之后每次的remove实际上都没有实际执行，
            //因为每次都是new出来的JScrollPane ，新的JScrollPane不在jframe上
            //之后那些就全都是连锁的问题了，组建处理不当会产生很多奇怪的问题，刚开始就应该把jsp的初始化放在外面
            this.add(jsp, BorderLayout.CENTER);
            this.setBounds(100, 150, 500, 500);
            this.repaint();
        }


下面这个是改过的


 
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
 
public class test 
{
    public static void main(String[] args) 
    {
        new f();
    }
}
 
class f extends JFrame implements ActionListener
{
    JButton east, west, north, south;
    JPanel peast, pwest, pnorth, psouth;
    JScrollPane jsp;
    JTable table;
    Object a[][];
    Object name[] = {"地方", "dsf", "few", "fsfse"};
     
    f()
    {
        east = new JButton("窗口变大");
        east.addActionListener(this);
        west = new JButton("窗口变小");
        west.addActionListener(this);
        north = new JButton("移除其他组件"); 
 
        north.addActionListener(this);
        south = new JButton("显示所有组件");
        south.addActionListener(this);
         
        a = new Object[20][4];
        for(int i=0; i<20; i++)
        {
            a[i][0] = i;
            a[i][1] = i;
            a[i][2] = i;
            a[i][3] = i;
        }
        table = new JTable(a, name);
         
        peast = new JPanel(); 
        pwest = new JPanel();
        pnorth = new JPanel();
        psouth = new JPanel();
        jsp = new JScrollPane(table);  //直接赋值
        peast.add(east);
        pwest.add(west);
        pnorth.add(north);
        psouth.add(south);
         
        //north.setSize(100, 100);        //这两条语句是不是有问题呢？
        //pnorth.setSize(100, 100);        //为什么按钮并没有改变大小？
         
        add(peast, BorderLayout.EAST);
        add(pwest, BorderLayout.WEST);
        add(pnorth, BorderLayout.NORTH);
        add(psouth, BorderLayout.SOUTH);
        add(jsp, BorderLayout.CENTER);
        setBounds(100, 150, 350, 350);
        setVisible(true);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
     
    public void actionPerformed(ActionEvent e) 
    {
        if(e.getSource() == east)
        {
//            this.getContentPane().remove(jsp);   
//            this.add(jsp, BorderLayout.CENTER);  这没看懂，为什么要去掉，再加上
            this.setBounds(100, 150, 500, 500);
            this.repaint();
        }
        else if(e.getSource() == west) 
 
        {
//            jsp = new JScrollPane(table);
//            this.getContentPane().remove(jsp);
//            this.add(jsp, BorderLayout.CENTER);
            this.setBounds(100, 150, 300, 300);
            this.repaint();
        }
        else if(e.getSource() == north)
        {
            this.getContentPane().removeAll();
            this.add(pnorth, BorderLayout.NORTH);
            this.add(psouth, BorderLayout.SOUTH);
            this.repaint();
        }
        else if(e.getSource() == south)
        {
//            jsp = new JScrollPane(table);
            this.getContentPane().removeAll();
            this.add(peast, BorderLayout.EAST);
            this.add(pwest, BorderLayout.WEST);
            this.add(pnorth, BorderLayout.NORTH);
            this.add(psouth, BorderLayout.SOUTH);
            this.add(jsp, BorderLayout.CENTER);
            this.setBounds(100, 150, 500, 350);
            this.repaint();
        }
    }
}


BorderLayout貌似不可以设置每个位置的大小。
[解决办法]

public class JTableScrollTest extends JFrame implements ActionListener {
public static void main(String[] args){
new JTableScrollTest();
}

private JButton east, west, north, south;
private JPanel peast, pwest, pnorth, psouth;
private JScrollPane jsp;
private JTable table;
private Object a[][];
private Object name[] = {"地方", "dsf", "few", "fsfse"};

public JTableScrollTest(){
super("测试JTable对界面的影响");

east = new JButton("窗口变大");
east.addActionListener(this);
west = new JButton("窗口变小");
west.addActionListener(this);


north = new JButton("移除其他组件");
north.addActionListener(this);
south = new JButton("显示所有组件");
south.addActionListener(this);

a = new Object[20][4];
for(int i=0; i<20; i++){
a[i][0] = i;
a[i][1] = i;
a[i][2] = i;
a[i][3] = i;
}
table = new JTable(a, name);

peast = new JPanel();
pwest = new JPanel();
pnorth = new JPanel();
psouth = new JPanel();
jsp = new JScrollPane(table);
peast.add(east);
pwest.add(west);
pnorth.add(north);
psouth.add(south);

//north.setSize(100, 100); //这两条语句是不是有问题呢？
//pnorth.setSize(100, 100); //为什么按钮并没有改变大小？

getContentPane().add(peast, BorderLayout.EAST);
getContentPane().add(pwest, BorderLayout.WEST);
getContentPane().add(pnorth, BorderLayout.NORTH);
getContentPane().add(psouth, BorderLayout.SOUTH);
getContentPane().add(jsp, BorderLayout.CENTER);
setBounds(100, 150, 350, 350);
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}

public void actionPerformed(ActionEvent e) {
if(e.getSource() == east){
// jsp = new JScrollPane(table);
// this.getContentPane().remove(jsp);
// this.getContentPane().add(jsp, BorderLayout.CENTER);
// this.setBounds(100, 150, 500, 500);
this.setSize(500, 500);
this.repaint();



}else if(e.getSource() == west){
// jsp = new JScrollPane(table);
// this.getContentPane().remove(jsp);
// this.getContentPane().add(jsp, BorderLayout.CENTER);
// this.setBounds(100, 150, 300, 300);
this.setSize(300, 300);
this.repaint();

}else if(e.getSource() == north){
this.getContentPane().removeAll();
this.repaint();
this.getContentPane().add(pnorth, BorderLayout.NORTH);
this.getContentPane().add(psouth, BorderLayout.SOUTH);

}else if(e.getSource() == south){
// jsp = new JScrollPane(table);
this.getContentPane().removeAll();
this.getContentPane().add(peast, BorderLayout.EAST);
this.getContentPane().add(pwest, BorderLayout.WEST);
this.getContentPane().add(pnorth, BorderLayout.NORTH);
this.getContentPane().add(psouth, BorderLayout.SOUTH);
this.getContentPane().add(jsp, BorderLayout.CENTER);
// this.setBounds(100, 150, 500, 350);
this.setSize(500, 350);
this.repaint();
}
}
}

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