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

我添加了 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()){我++；}System.out.println(i);k=i+2；list.removeElementAt(i);listName.removeElementAt(i);System.out.println(k);c.getContentPane().remove(k);

但是当我选择第一个单选按钮时，应该删除第一个 JButton，因为 k=i+2;而不是删除这个，而是删除 TextArea(第一个).当我选择第三个单选按钮时，第一个 JButton 被删除.谁能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 {字符串按钮名称；JPanel radioPanel = new JPanel();ButtonGroup 组 = new ButtonGroup();枚举 enl;整数结果；动作事件 e;JRadioButton birdButton[];整数 i, k;向量<字符串>列表名称;向量<J分量>列表;容器 c;public RadioDemo(Vector listName,Vector list,Container c) {birdButton=新的 JRadioButton[listName.size()];this.listName=列表名；这个.c=c;这个.list=列表；我 = 0;对于(字符串按钮名称:列表名称){birdButton[i] = new JRadioButton(buttonName);birdButton[i].setActionCommand(buttonName);group.add(birdButton[i]);birdButton[i].addActionListener(this);radioPanel.add(birdButton[i]);我++；}birdButton[0].setSelected(true);radioPanel.setLayout(新的 BoxLayout(radioPanel,BoxLayout.Y_AXIS));//birdButton.setBorder(BorderFactory.createEmptyBorder(5,5,5,5));结果 = JOptionPane.showConfirmDialog(null, radioPanel, "请选择", JOptionPane.OK_CANCEL_OPTION);展示();}/** 监听单选按钮.*/公共无效actionPerformed(ActionEvent e){这.e = e;}公共无效显示(){如果(结果 == JOptionPane.OK_OPTION){我 = 0;k = 0;while (!birdButton[i].isSelected()) {我++；}System.out.println(i);k = 我 + 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Container默认是contentPanep>

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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