JList - 选择多个项目

Question

当我想自动选择 JList 中的多个值时，我在 JList 中遇到了这个 setSelectedValue() 方法的问题，它仍然只选择了一个。有办法吗？

 String[] items = { "Item 1", "Item 2", "Item 3", "Item 4" };
      final JList theList = new JList(items);
      theList.setSelectedValue("Item 1",true);
      theList.setSelectedValue("Item 2",true);

此代码仅显示选定的Item 2。

Answer 1

调用 JList.setSelectionMode(ListSelectionModel.MULTIPLE_INTERVAL_SELECTION) 后使用 JList.setSelectedIndices(int[])。

EG

import javax.swing.*;
import java.io.*;
import java.util.ArrayList;
class MultiSelectList {
    public static void main(String[] args) throws Exception {
        File f = new File("MultiSelectList.java");
        InputStream is = new FileInputStream(f);
        InputStreamReader isr = new InputStreamReader(is);
        BufferedReader br = new BufferedReader(isr);
        final ArrayList<String> lines = new ArrayList<String>();
        String line = br.readLine();
        while (line!=null) {
            lines.add(line);
            line = br.readLine();
        }
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                JList list = new JList(lines.toArray());
                list.setSelectionMode(
                    ListSelectionModel.MULTIPLE_INTERVAL_SELECTION);
                int[] select = {19, 20, 22};
                list.setSelectedIndices(select);
                JOptionPane.showMessageDialog(null, new JScrollPane(list));
            }
        });
    }
}

屏幕截图

Answer 2

list.getSelectionModel().setSelectionInterval(...);

或者如果选择不连续，那么您需要使用多个

list.getSelectionModel().addSelectionInterval(...);

Answer 3

当您使用 NetBeans GUI 编辑器时，您可以自定义为 JList 生成的创建后代码，如下所示。

Answer 4

import javax.swing.*;
import java.io.*;
import java.util.ArrayList;

class MultiSelectList {
    public static void main(String[] args) throws Exception {
        File f = new File("MultiSelectList.java");
        InputStream is = new FileInputStream(f);
        InputStreamReader isr = new InputStreamReader(is);
        BufferedReader br = new BufferedReader(isr);
        final ArrayList<String> lines = new ArrayList<String>();
        String line = br.readLine();
        while (line!=null) {
            lines.add(line);
            line = br.readLine();
        }
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                JList list = new JList(lines.toArray());
                list.setSelectionMode(
                    ListSelectionModel.MULTIPLE_INTERVAL_SELECTION);
                int[] select = {19, 20, 22};
                list.setSelectedIndices(select);
                JOptionPane.showMessageDialog(null, new JScrollPane(list));
            }
        });
    }
}