将 Jpanel 添加到 Jscrollbar

Question

我正在尝试将 Jpanel 添加到 JscrollBAr，但是当我运行 java 它不起作用时。这是一个带有问题的 RadioButton。你能帮我吗？这是我的 class jpanel :

public class yesnoPanel extends JPanel {
private JPanel quest;
private JPanel answ;
public yesnoPanel(String q){
    JPanel pan = new JPanel();
    JRadioButton yes = new JRadioButton("yes");
    JRadioButton no = new JRadioButton("no");
    ButtonGroup bg = new ButtonGroup();
    JTextArea question = new JTextArea(1,20);
    question.setText(q);
    JPanel pan2 = new JPanel();
    pan2.add(question);
    bg.add(yes);
    bg.add(no);
    pan.add(yes);
    pan.add(no);
    this.quest=pan2;
    this.answ=pan;
}

我可以在使用 JFrame 时显示它们，但不能使用 Jscrollbar 这是我主要的 jscrollbar :

public static void main(String[] args) {
    JFrame fram = new JFrame();
    yesnoPanel question = new yesnoPanel("are you ok");
    JPanel q = question.getQuestion();
    JPanel a = question.getAnsw();
    JPanel all = new JPanel();
    all.add(q);
    all.add(a);
    yesnoPanel question2 = new yesnoPanel("sure ?");
    JPanel q2 = question2.getQuestion();
    q2.setSize(200,500);
    JPanel a2 = question2.getAnsw();
    JPanel all2 = new JPanel();
    all2.add(q2,BorderLayout.WEST);
    all2.add(a2);

    JScrollPane scroll = new JScrollPane();
    scroll.setPreferredSize(new Dimension(100,100));
    scroll.setViewportView(all);
    scroll.setVisible(true);
}

感谢大家

Answer 1

用这个替换 main 方法中的最后几行以使其工作。

JPanel master = new JPanel();
master.add(all);
master.add(all2);

JScrollPane scroll = new JScrollPane(master);
scroll.setPreferredSize(new Dimension(100,100));
scroll.setViewportView(all);
scroll.setVisible(true);

fram.add(scroll);
fram.pack();
fram.setVisible(true);
fram.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

将 Jpanel 添加到 Jscrollbar

Add Jpanel to a Jscrollbar

java

swing

jpanel

jframe

jscrollpane