我正在使用一个Timer来切换一个布尔值，但不是像它应该的那样每隔250ms触发一次，它会尽可能快地触发。这是我的代码：
package com.cgp.tetris;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.Timer;
import java.util.TimerTask;
import javax.imageio.ImageIO;
import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.Clip;
import javax.sound.sampled.DataLine;
import javax.sound.sampled.LineUnavailableException;
import javax.sound.sampled.UnsupportedAudioFileException;
import javax.sound.sampled.DataLine.Info;
import javax.swing.AbstractAction;
import javax.swing.ActionMap;
import javax.swing.InputMap;
import javax.swing.JPanel;
import javax.swing.KeyStroke;
public class SinglePlayerMenu extends JPanel implements Runnable {
private static final long serialVersionUID = 1L;
private Thread thread;
private AudioInputStream themestream, blipstream;
private Clip clip, blipclip;
private BufferedImage base, bi1, bi2, bi3, bi4, bi1s, bi2s, bi3s, bi4s;
private boolean typeselected = false, b1 = true, b2 = false, b3 = true, b4 = false, b5 = false, b6 = false, b1a = true, b2a = false;
public SinglePlayerMenu() {
super();
this.addComponentListener(new ComponentAdapter() {
public void componentShown(ComponentEvent e) {
SinglePlayerMenu.this.requestFocusInWindow();
}
});
}
public void addNotify() {
super.addNotify();
thread = new Thread(this);
thread.start();
}
public void paint(Graphics g) {
super.paint(g);
g.drawImage(base, 0, 0, 640, 576, null);
if (b1) {
g.drawImage(bi1s, 80, 156, 240, 40, null);
} else if (!b1) {
g.drawImage(bi1, 80, 156, 240, 40, null);
}
if (b2) {
g.drawImage(bi2s, 324, 156, 236, 40, null);
} else if (!b2) {
g.drawImage(bi2, 324, 156, 236, 40, null);
}
if (b3) {
g.drawImage(bi1s, 80, 380, 240, 40, null);
} else if (!b3) {
g.drawImage(bi1, 80, 380, 240, 40, null);
}
if (b4) {
g.drawImage(bi2s, 324, 380, 236, 40, null);
} else if (!b4) {
g.drawImage(bi2, 324, 380, 236, 40, null);
}
if (b5) {
g.drawImage(bi3s, 80, 444, 240, 40, null);
} else if (!b5) {
g.drawImage(bi3, 80, 444, 240, 40, null);
}
if (b6) {
g.drawImage(bi4s, 324, 444, 236, 40, null);
} else if (!b6) {
g.drawImage(bi4, 324, 444, 236, 40, null);
}
}
public void run() {
sound();
loadImages();
bind();
while (true) {
repaint();
try {
Thread.sleep(2);
} catch (InterruptedException e) {
e.printStackTrace();
}
checks();
}
}
private void checks() {
Timer timer = new Timer();
timer.scheduleAtFixedRate(new TimerTask() {
public void run() {
System.out.println("Being run");
if (b1a && !typeselected) {
b1 = !b1;
}
}
}, java.util.Calendar.getInstance().getTime(), 250);
}
private void bind() {
InputMap im = getInputMap();
ActionMap am = getActionMap();
im.put(KeyStroke.getKeyStroke("LEFT"), "left");
am.put("left", new AbstractAction() {
private static final long serialVersionUID = 1L;
public void actionPerformed(ActionEvent e) {
if (!typeselected) {
if (!b1a) {
blipclip.start();
blipclip.setFramePosition(0);
}
b1 = true;
b2 = false;
b1a = true;
b2a = false;
} else if (typeselected) {
}
}
});
im.put(KeyStroke.getKeyStroke("RIGHT"), "right");
am.put("right", new AbstractAction() {
private static final long serialVersionUID = 1L;
public void actionPerformed(ActionEvent e) {
if (!typeselected) {
if (!b2a) {
blipclip.start();
blipclip.setFramePosition(0);
}
b2 = true;
b1 = false;
b1a = false;
b2a = true;
} else if (typeselected) {
}
}
});
im.put(KeyStroke.getKeyStroke("SPACE"), "space");
am.put("space", new AbstractAction() {
private static final long serialVersionUID = 1L;
public void actionPerformed(ActionEvent e) {
if (!typeselected) {
typeselected = true;
b1=b1a;
b2=b2a;
} else if (typeselected) {
}
}
});
}
private void loadImages() {
try {
base = ImageIO.read(new File("res/base.png"));
bi1 = ImageIO.read(new File("res/1.png"));
bi2 = ImageIO.read(new File("res/2.png"));
bi3 = ImageIO.read(new File("res/3.png"));
bi4 = ImageIO.read(new File("res/4.png"));
bi1s = ImageIO.read(new File("res/1s.png"));
bi2s = ImageIO.read(new File("res/2s.png"));
bi3s = ImageIO.read(new File("res/3s.png"));
bi4s = ImageIO.read(new File("res/4s.png"));
} catch (IOException e) {
e.printStackTrace();
}
}
private void sound() {
File theme = new File("res/playtheme.wav");
try {
themestream = AudioSystem.getAudioInputStream(theme);
} catch (UnsupportedAudioFileException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
DataLine.Info info = new DataLine.Info(Clip.class, themestream.getFormat());
clip = null;
try {
clip = (Clip) AudioSystem.getLine(info);
} catch (LineUnavailableException e) {
e.printStackTrace();
}
try {
clip.open(themestream);
} catch (LineUnavailableException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
File blip = new File("res/blip.wav");
try {
blipstream = AudioSystem.getAudioInputStream(blip);
} catch (UnsupportedAudioFileException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
DataLine.Info blipinfo = new DataLine.Info(Clip.class, blipstream.getFormat());
blipclip = null;
try {
blipclip = (Clip) AudioSystem.getLine(blipinfo);
} catch (LineUnavailableException e) {
e.printStackTrace();
}
try {
blipclip.open(blipstream);
} catch (LineUnavailableException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
public void startClip() {
clip.loop(Clip.LOOP_CONTINUOUSLY);
blipclip.start();
blipclip.setFramePosition(0);
}
}
答案 0 :(得分：4)
你的基本代码对我来说不对：
自定义绘画应在paintComponent（）方法中完成。
使用Swing时，您应该使用Swing Timer。
你有一个每2ms重绘一次的线程。这是你的问题吗？
您不需要带有while（）循环的Thread。这就是你使用Timer的原因。所以我猜测Thread和Timer应该组合成一个Swing Timer。当时间触发时，您更新变量，然后调用repaint（）。
答案 1 :(得分：0)
来自Timer.scheduleAtFixedRate - 文档：
在固定费率执行中，每次执行都是相对于 初始执行的预定执行时间。如果执行是 因任何原因而延迟（例如垃圾收集或其他背景 活动），两个或多个执行将快速连续发生 “跟上来。”从长远来看，执行的频率将是 恰好是指定时期的倒数（假设系统 Object.wait（long）的时钟是准确的。）
如果您的任务执行时间超过250毫秒，则会在第一个任务之后立即执行以下任务，然后执行该任务，等等。也许您打算使用Timer.schedule代替？
为重复的固定延迟执行安排指定的任务， 从指定时间开始。随后的处决发生在 大约定期的间隔，以指定的时间间隔分开。
在固定延迟执行中，每次执行都是相对于 上次执行的实际执行时间。如果执行是 因任何原因而延迟（例如垃圾收集或其他背景 活动），随后的处决也会延迟。