JList单元格中的JButton不可单击

Question

在我目前的swing项目中,我有一个JList显示所有活动套接字,每个单元格都有一个JButton关闭该套接字.但是JButton单元格中的单击不可点击:侦听器不会被触发.

我已将代码修改为最小,如下所示.

private class ConnectionListRenderer extends JButton implements ListCellRenderer {

    public Component getListCellRendererComponent(JList jlist, Object o, int i, boolean bln, boolean bln1) {

        addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent evt) {
                //do something (close the socket in my project)
            }
        });
        return this;
    }
}


jList.setCellRenderer(new ConnectionListRenderer());

列表看起来很好,但是上面的按钮不可点击.我错了还是JList只是不支持JButton被解雇？

Answer 1

这是一个似乎有效的示例,尽管您没有获得正常按钮单击的相同视觉效果.也许有比我更好的绘画技巧的人可以改进这个以模拟视觉按下的按钮效果.

import java.awt.*;
import java.awt.event.*;

import javax.swing.*;

/**
 * A JList of JButtons.
 */
public class JButtonListDemo implements Runnable
{
  private JList jlist;

  public static void main(String args[])
  {
    SwingUtilities.invokeLater(new JButtonListDemo());
  }

  public void run()
  {
    Object[] items = new ButtonItem[] {
        new ButtonItem("Apple"),
        new ButtonItem("Banana"),
        new ButtonItem("Carrot"),
        new ButtonItem("Date"),
        new ButtonItem("Eggplant"),
        new ButtonItem("Fig"),
        new ButtonItem("Guava"),
    };

    jlist = new JList(items);
    jlist.setCellRenderer(new ButtonListRenderer());
    jlist.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
    jlist.setVisibleRowCount(5);
    jlist.addMouseListener(new MouseAdapter()
    {
      @Override
      public void mouseClicked(MouseEvent event)
      {
        clickButtonAt(event.getPoint());
      }
    });

    JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.getContentPane().add(new JScrollPane(jlist));
    frame.pack();
    frame.setLocationRelativeTo(null);
    frame.setVisible(true);
  }

  private void clickButtonAt(Point point)
  {
    int index = jlist.locationToIndex(point);
    ButtonItem item = (ButtonItem) jlist.getModel().getElementAt(index);
    item.getButton().doClick();
//    jlist.repaint(jlist.getCellBounds(index, index));
  }

  public class ButtonItem
  {
    private JButton button;

    public ButtonItem(String name)
    {
      this.button = new JButton(name);
      button.addActionListener(new ActionListener()
      {
        @Override
        public void actionPerformed(ActionEvent e)
        {
          System.out.println(button.getText() + " was clicked.");
        }
      });
    }

    public JButton getButton()
    {
      return button;
    }

    @Override
    public String toString()
    {
      return button.getText();
    }
  }

  class ButtonListRenderer extends JButton implements ListCellRenderer
  {
    public Component getListCellRendererComponent(JList comp, Object value, int index,
                                                  boolean isSelected, boolean hasFocus)
    {
      setEnabled(comp.isEnabled());
      setFont(comp.getFont());
      setText(value.toString());

      if (isSelected)
      {
        setBackground(comp.getSelectionBackground());
        setForeground(comp.getSelectionForeground());
      }
      else
      {
        setBackground(comp.getBackground());
        setForeground(comp.getForeground());
      }

      return this;
    }
  }
}

或者,您可以始终在JPanel上垂直布局JButton(可能使用新的GridLayout(0,1)),然后将您的JPanel放在JScrollPane中,从而模拟JButtons的JList.

Answer 2

渲染不是“真实的”组件，它们是绘制在父组件表面上的“橡皮图章”。他们没有“物理”存在。

AJList将只有一个渲染实例，这用于将列表模型中的每一项“标记”到视图上。

开箱即用，JList不可编辑。