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我希望这个 JScrollPane 每次调用 Action Listener 时都将其列表更改为完全不同的列表。我不完全确定如何去做。我尝试更改 JList，重新绘制 ScrollPane 并重新验证它，但它并没有带来预期的效果。我写了一个可编译的小程序，在这里解释了我的问题：

import javax.swing.*;
import javax.swing.border.TitledBorder;
import java.awt.*;
import java.awt.event.*;
import java.sql.SQLException;

@SuppressWarnings("serial")
public class TestFrame extends JFrame {
public final Dimension SCROLL_PANE_DIMENSION = new Dimension(200, 100);
private JComboBox<String> comboNames;
private JPanel panel = new JPanel();
private JList<String> availableList;
private JScrollPane theScrollPane;
private boolean string1Used = true;
String[] strings = { "Aaardvark", "Adam", "Alms" };
String[] strings2 = { "Bad", "Bugs", "Bunny" };

public static void main(String[] args){
    try {
        TestFrame frame = new TestFrame();
        frame.setVisible(true);
    } catch (SQLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

public TestFrame() throws SQLException {
    String[] comboStrings = { "Doesn't", "matter", "here" };

    this.setSize(300,200);

    availableList = new JList<String>(strings);

    theScrollPane = new JScrollPane(availableList);

    theScrollPane = new JScrollPane(availableList);
    theScrollPane.setPreferredSize(SCROLL_PANE_DIMENSION);
    theScrollPane.setSize(SCROLL_PANE_DIMENSION);
    theScrollPane.setBorder(BorderFactory.createTitledBorder(
            BorderFactory.createEtchedBorder(), "Sub Conditions",
            TitledBorder.CENTER, 0));

    availableList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
    availableList.setSelectedIndex(0);
    availableList.setVisibleRowCount(5);
    availableList.setSize(SCROLL_PANE_DIMENSION);

    comboNames = new JComboBox<String>(comboStrings);

    comboNames.addActionListener(new ConditionComboListener());

    panel = new JPanel();


    this.add(panel);


    panel.add(comboNames);
    panel.add(theScrollPane);

}

private class ConditionComboListener implements ActionListener {

    @Override
    public void actionPerformed(ActionEvent arg0) {
        refreshSubConditionList();
    }

    private void refreshSubConditionList() {
        if (string1Used) {
            System.out.println("Switching to Strings2");
            availableList = new JList<String>(strings2);
            string1Used = false;
        } else{
            System.out.println("Switching to Strings");
            availableList = new JList<String>(strings);
            string1Used = true;
        }
        theScrollPane = new JScrollPane(availableList);
        theScrollPane.revalidate();
        theScrollPane.repaint();
    }

}

}

在此示例中，我希望 JScrollPane 内的列表在每次更改 JComboBox 中的内容时在数组 strings1 和 strings2 之间切换。我还希望此更改在我更改组合框中的内容后立即可见，而不是稍后。正如您从编译后的代码中看到的那样，它并不完全是这样。我究竟做错了什么？为什么当我想要它时它不改变列表？

4

1 回答 1

9

创建新的滚动窗格不会将滚动窗格添加到面板中。

无论如何，没有必要继续创建新的滚动窗格。只需更改滚动窗格中显示的组件：

//theScrollPane = new JScrollPane(availableList);
//theScrollPane.revalidate();
//theScrollPane.repaint();
theScrollPane.setViewportView(availableList);
于 2013-03-11T05:55:41.843 回答