我正在使用鼠标监听器来按下和释放鼠标。当按下鼠标时,我想要一个递增变量的计数器,而当松开鼠标时,我想要递减该变量。现在,我的代码正在运行,但增量太快了,我想减慢它的速度,因为我在游戏中使用这些数字作为坐标。我尝试添加一个 Thread.sleep(100) 但我得到的是倾斜的输出。看起来好像有多个线程在同时运行,而且我到处都是数字。下面是示例代码。
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JButton;
import java.awt.event.*;
import java.awt.event.ActionListener;
import java.lang.*;
public class Sample extends JFrame {
private JPanel jp = new JPanel();
int i = 0;
boolean once = true;
boolean on = true;
Thread t1 = new Thread(new Increase());
Thread t2 = new Thread(new Decrease());
public sample() {
setVisible(true);
setSize(300, 300);
setDefaultCloseOperation(EXIT_ON_CLOSE);
add(jp);
addMouseListener(new MouseAdapter() {
public void mousePressed(MouseEvent event) {
if (!once) //false
{
t2.interrupt();
}
if (once) //true
{
once = false;
t1.start();
}
else {
t1 = new Thread(new Increase());
t1.start();
}
}
public void mouseReleased(MouseEvent event) {
t1.interrupt();
if (on) //true
{
on = false;
t2.start();
}
else {
t2 = new Thread(new Decrease());
t2.start();
}
}
});
}
public static void main(String[] args) {
new Sample();
}
public int getI() {
return i;
}
public void setI(int num) {
i = num;
}
class Increase implements Runnable {
public void run() {
int num = getI();
while (!Thread.currentThread().isInterrupted()) {
try {
setI(++num);
Thread.sleep(100);
System.out.println(num);
}
catch (InterruptedException e) {
}
}
}
}
//Thread.currentThread().isInterrupted()
class Decrease implements Runnable {
public void run() {
int num = getI();
while (!Thread.currentThread().isInterrupted()) {
try {
setI(--num);
Thread.sleep(100);
System.out.println(num);
}
catch (InterruptedException e) {
}
}
}
}
}
最佳答案
您可能遇到了两个线程之间的竞争条件,i
不是可变的这一事实也表明线程可能不会使用彼此相同的实际值。
线程也是不可重入的,也就是说一旦run
方法存在,就不能重新启动。
您只需使用一个 Thread
和一个“增量”(或更改)值即可获得相同的结果。
以下示例使用 Swing Timer
,因为它更简单并且允许我安全地更新 UI,但原理是相同的。
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private JLabel label;
private Timer timer;
private int value = 0;
private int delta = 1;
public TestPane() {
setLayout(new GridBagLayout());
label = new JLabel("0");
add(label);
addMouseListener(new MouseAdapter() {
@Override
public void mousePressed(MouseEvent e) {
delta *= -1;
}
@Override
public void mouseReleased(MouseEvent e) {
delta *= -1;
}
});
timer = new Timer(100, new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
setValue(getValue() + delta);
}
});
timer.start();
}
@Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
public int getValue() {
return value;
}
public void setValue(int value) {
this.value = value;
label.setText(Integer.toString(value));
}
}
}
更新了双“线程”
只是因为我完全疯了,而且很高兴能展示额外的工作量。此示例使用两个 Thread
。
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel implements Value {
private JLabel label;
private volatile int value = 0;
private ManipulateRunner incrementRunner;
private ManipulateRunner decrementRunner;
private Thread incrementThread;
private Thread decrementThread;
public TestPane() {
incrementRunner = new ManipulateRunner(this, 1);
decrementRunner = new ManipulateRunner(this, -1);
setLayout(new GridBagLayout());
label = new JLabel("0");
add(label);
addMouseListener(new MouseAdapter() {
@Override
public void mousePressed(MouseEvent e) {
decrementRunner.pause();
if (incrementThread == null) {
incrementThread = new Thread(incrementRunner);
incrementThread.start();
}
incrementRunner.resume();
}
@Override
public void mouseReleased(MouseEvent e) {
incrementRunner.pause();
if (decrementThread == null) {
decrementThread = new Thread(decrementRunner);
decrementThread.start();
}
decrementRunner.resume();
}
});
}
@Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
@Override
public int getValue() {
return value;
}
@Override
public void setValue(final int value) {
if (EventQueue.isDispatchThread()) {
this.value = value;
label.setText(Integer.toString(value));
} else {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
setValue(value);
}
});
}
}
}
public static interface Value {
public int getValue();
public void setValue(int value);
}
public static class ManipulateRunner implements Runnable {
protected final Object pauseLock = new Object();
private int delta;
private AtomicBoolean paused = new AtomicBoolean(false);
private AtomicBoolean stopped = new AtomicBoolean(false);
private Value value;
public ManipulateRunner(Value value, int delta) {
this.delta = delta;
this.value = value;
}
public void pause() {
if (!paused.get() && !stopped.get()) {
paused.set(true);
synchronized (pauseLock) {
pauseLock.notify();
}
}
}
public void resume() {
if (paused.get() && !stopped.get()) {
paused.set(false);
synchronized (pauseLock) {
pauseLock.notify();
}
}
}
public void stop() {
if (!stopped.get()) {
stopped.set(true);
synchronized (pauseLock) {
pauseLock.notify();
}
}
}
@Override
public void run() {
while (!stopped.get()) {
while (!stopped.get() && paused.get()) {
synchronized (pauseLock) {
try {
pauseLock.wait();
} catch (InterruptedException ex) {
}
}
}
if (!stopped.get()) {
value.setValue(value.getValue() + delta);
try {
Thread.sleep(100);
} catch (InterruptedException ex) {
}
}
}
}
}
}
就个人而言,最简单有效的解决方案是更好的解决方案,但我就是这样
关于java - 希望使用 thread.sleep 暂停线程,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/30990477/