Java容器删除方法无法正常工作 [英] Java Container remove method not working correctly

问题描述

我hava添加1.TextArea 2.TextField
然后我开始在容器上连续添加JButton ...，现在通过使用JRadioButton我想使用此代码从容器中删除JButton

  i = 0; 
 k = 0; 
 while（！birdButton [i] .isSelected（））{
 i ++; 
} 
 System.out.println（i）; 
 k = i + 2; 
 list.removeElementAt（i）; 
 listName.removeElementAt（i）; 
 System.out.println（k）; 
 c.getContentPane（）。remove（k）; 
  

但当我选择第一个radiobutton时，由于k = i + 2，应删除第一个JButton;
而不是删除这个删除TextArea（第一个）。
当我选择第3个radiobutton然后第1个JButton被删除。任何人都可以让我知道问题是什么？还有 System.out.println（i）; System.out.println（k）; 没有打印任何值....这里是代码

 公共类RadioDemo实现ActionListener {
 
 String buttonName; 
 JPanel radioPanel = new JPanel（）; 
 ButtonGroup group = new ButtonGroup（）; 
枚举enl; 
 int result; 
 ActionEvent e; 
 JRadioButton birdButton []; 
 int i，k; 
 
 Vector< String>列表名称; 
 Vector< JComponent>列表; 
集装箱c; 
 
 public RadioDemo（Vector< String> listName，Vector< JComponent> list，Container c）{
 
 birdButton = new JRadioButton [listName.size（）]; 
 this.listName = listName; 
 this.c = c; 
 this.list = list; 
 
 i = 0; 
 for（String buttonName：listName）{
 birdButton [i] = new JRadioButton（buttonName）; 
 birdButton [i] .setActionCommand（buttonName）; 
 group.add（birdButton [i]）; 
 birdButton [i] .addActionListener（this）; 
 radioPanel.add（birdButton [i]）; 
 i ++; 
} 
 
 birdButton [0] .setSelected（true）; 
 radioPanel.setLayout（新BoxLayout 
 
（radioPanel，BoxLayout.Y_AXIS））; 
 //birdButton.setBorder 
 
（BorderFactory.createEmptyBorder（5,5,5,5））; 
 result = JOptionPane.showConfirmDialog（null，radioPanel，Please choose，JOptionPane.OK_CANCEL_OPTION）; 
 show（）; 
} 
 
 / **收听单选按钮。 * / 
 public void actionPerformed（ActionEvent e）{
 this.e = e; 
} 
 
 public void show（）{
 if（result == JOptionPane.OK_OPTION）{
 i = 0; 
 k = 0; 
 while（！birdButton [i] .isSelected（））{
 i ++; 
 
} 
 System.out.println（i）; 
 k = i + 2; 
 list.removeElementAt（i）; 
 listName.removeElementAt（i）; 
 System.out.println（k）; 
 c.getContentPane（）。remove（k）; 
 c.getContentPane（）。validate（）; 
 
 // System.out.println（e.getActionCommand（））; 
 // c.getContentPane（）。rePaint（）; 
} 
} 
 
} 
  

解决方案

getContentPane（）返回的容器默认为 contentPane 由。

i hava added 1.TextArea 2.TextField then i start adding JButton successively on container...,now by using JRadioButton i want to remove JButton from container using this code

i=0;
k=0;
while(!birdButton[i].isSelected()){
    i++;    
}   
System.out.println(i);
k=i+2;
list.removeElementAt(i);
listName.removeElementAt(i);
System.out.println(k);
c.getContentPane().remove(k);

but when i select the 1st radiobutton 1st JButton should be deleted because of k=i+2; instead of deleting this one it deletes the TextArea(1st one). when i select the 3rd radiobutton then 1st JButton is deleted. can anyone let me know what the problem is? and also System.out.println(i); System.out.println(k); is not printing any value....here is the code

public class RadioDemo implements ActionListener {

    String buttonName;
    JPanel radioPanel = new JPanel();
    ButtonGroup group = new ButtonGroup();
    Enumeration enl;
    int result;
    ActionEvent e;
    JRadioButton birdButton[];
    int i, k;

    Vector<String> listName;
    Vector<JComponent> list;
    Container c;

    public RadioDemo(Vector<String> listName,Vector<JComponent> list,Container c) {

        birdButton=new JRadioButton[listName.size()];
        this.listName=listName;
        this.c=c;
        this.list=list;

        i = 0;
        for (String buttonName : listName){
               birdButton[i] = new JRadioButton(buttonName);
               birdButton[i].setActionCommand(buttonName);
               group.add(birdButton[i]);
               birdButton[i].addActionListener(this);
               radioPanel.add(birdButton[i]);
               i++;
         }

        birdButton[0].setSelected(true);
        radioPanel.setLayout(new BoxLayout

        (radioPanel,BoxLayout.Y_AXIS));
                                    //birdButton.setBorder

        (BorderFactory.createEmptyBorder(5,5,5,5));
        result = JOptionPane.showConfirmDialog(null, radioPanel, "Please choose", JOptionPane.OK_CANCEL_OPTION);                
        show();
    }

    /** Listens to the radio buttons. */
    public void actionPerformed(ActionEvent e) {
        this.e = e;
    }

    public void show() {
        if (result == JOptionPane.OK_OPTION) {
            i = 0;
            k = 0;
            while (!birdButton[i].isSelected()) {
                i++;

            }
            System.out.println(i);
            k = i + 2;
            list.removeElementAt(i);
            listName.removeElementAt(i);
            System.out.println(k);
            c.getContentPane().remove(k);
            c.getContentPane().validate();

            // System.out.println(e.getActionCommand());
            // c.getContentPane().rePaint();
        }
    }

}

解决方案

The Container returned by getContentPane() is, by default, the contentPane of a JRootPane managed by the top-level container, JFrame. Although, "as a convenience, the add method and its variants, remove and setLayout have been overridden to forward to the contentPane as necessary," there's no a priori way to know about the frame's internal use of component indices.

Instead, add on your own JComponent to the frame and operate on it; JPanel is a common choice.

Addendum: Also consider an alternative layout such as CardLayout, illustrated here.

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