java - 单击 Swing JTable 中的行时出现意外的事件顺序

Question

单击 JTable 中的行时的默认行为似乎是...

1 event=javax.swing.event.ListSelectionEvent[ source=javax.swing.DefaultListSelectionModel 673443626 ~{0} firstIndex= 0 lastIndex= 0 isAdjusting= true ]
2 mousePressed
3 event=javax.swing.event.ListSelectionEvent[ source=javax.swing.DefaultListSelectionModel 673443626 ={0} firstIndex= 0 lastIndex= 0 isAdjusting= false ]
4 mouseReleased
5 mouseClicked

即使鼠标单击正在启动操作，JTable 事件也会在 mousePressed 之前潜入。为什么不是……

1 mousePressed
2 event=javax.swing.event.ListSelectionEvent[ source=javax.swing.DefaultListSelectionModel 673443626 ~{0} firstIndex= 0 lastIndex= 0 isAdjusting= true ]
3 event=javax.swing.event.ListSelectionEvent[ source=javax.swing.DefaultListSelectionModel 673443626 ={0} firstIndex= 0 lastIndex= 0 isAdjusting= false ]
4 mouseReleased
5 mouseClicked

我追求的行为是

1. 点击一行
2. 在 mousePressed 中，检查是否选择了行？
3. 否 - 只需选择行。
4. 是 - 执行一些操作。

目前发生的情况是，当单击未选定的行时，步骤 3 和 4 会同时发生。没有可用于检测该行是否被选中的鼠标事件 - 它将始终被选中。

或者换句话说...当您用鼠标单击 JTable 中的一行时，如何在单击事件期间测试该行是否在单击事件之前未被选中？

这是一个 SSCCE...

import java.awt.BorderLayout;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.JFrame;
import javax.swing.JTable;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;

public class JTableRowSelectTest {

    public static void main(String args[]) {

        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        Object rowData[][] = {{"Row1-Column1"}, {"Row2-Column1"}};
        Object columnNames[] = {"Column One"};
        final JTable table = new JTable(rowData, columnNames);

        table.addMouseListener(new MouseListener() {
            @Override
            public void mouseClicked(MouseEvent e) {
                final int row = table.rowAtPoint(e.getPoint());
                if (row >= 0 && table.isRowSelected(row)) {
                    System.out.println("mouseClicked on selected row");
                } else {
                    // never reached.
                    System.out.println("mouseClicked on un-selected row");
                }
            }

            @Override
            public void mousePressed(MouseEvent e) {
                final int row = table.rowAtPoint(e.getPoint());
                if (row >= 0 && table.isRowSelected(row)) {
                    System.out.println("mousePressed on selected row");
                } else {
                    // never reached.
                    System.out.println("mousePressed on un-selected row");
                }
            }

            @Override
            public void mouseReleased(MouseEvent e) {
                System.out.println("mouseReleased");
            }

            @Override
            public void mouseEntered(MouseEvent e) {
            }

            @Override
            public void mouseExited(MouseEvent e) {
            }
        });

        table.getSelectionModel().addListSelectionListener(new ListSelectionListener() {
            @Override
            public void valueChanged(ListSelectionEvent e) {
                System.out.println(e);
            }
        });

        frame.add(table, BorderLayout.CENTER);
        frame.setSize(300, 150);
        frame.setVisible(true);

    }
}

Answer 1

我已经遇到了这个问题:确定哪个事件触发了选择更改。解决办法是:

if (EventQueue.getCurrentEvent() instanceof MouseEvent) {
  // handler for mouse
} else if (EventQueue.getCurrentEvent() instanceof KeyEvent) {
  // handler for key
}

只需在 ListSelectionListener 中使用它即可。我不确定这种方法是否绝对正确，但它对我有用。

感谢@mKorbel。还有另一种可能性来检查选择更改是否是通过鼠标或键盘进行的。详情here .