如何让一个线程中的函数暂停执行

利用wait() notify() 写了一个。

import javaawtBorderLayout;

import javaawtColor;

import javaawtContainer;

import javaawtFlowLayout;

import javaawteventActionEvent;

import javaawteventActionListener;

import javaxswingJButton;

import javaxswingJFrame;

import javaxswingJPanel;

import javaxswingJTextField;

class ThreadClass extends JTextField implements Runnable {

//--- flag 控制线程状态 ---

private boolean flag = true;

public boolean isFlag() {

return flag;

}

public void setFlag(boolean flag) {

thisflag = flag;

}

//--- 通过累计计数模拟线程运行---

int times = 0;

//--- 设置文本框主要是显示线程状态 ---

public ThreadClass(String s) {

super(s);

setBackground(ColorORANGE);//---橘黄

setEditable(false);

setHorizontalAlignment(JTextFieldCENTER);

}

@Override

public void run() {

process();

}

private synchronized void process() {

while (true) {//无限循环

if (flag == true) {

thissetText("This is the " + (times++)

+ "th times running \n");

try {

Threadsleep(100);

} catch (InterruptedException ie) {

ieprintStackTrace();

}

notify();//--- 唤醒另一线程 --- ，本代码其实没有其他等待线程，这个可不用 ---

} else {

thissetText(" When times = " + times + "\n The thread is paused!");

try {

wait();//--- 进入等待

} catch (InterruptedException ie) {

ieprintStackTrace();

}

}

}

}

}

public class ThreadControll extends JFrame {

ThreadClass a = new ThreadClass("请按开始按钮！");

Thread startThread = null;

public ThreadControll(String s) {

super(s);

final Container c = getContentPane();

csetLayout(new BorderLayout());

JPanel jp = new JPanel(new FlowLayout());

JButton button_start = new JButton("开始");

JButton button_pause = new JButton("暂停");

JButton button_resume = new JButton("恢复");

jpadd(button_start);

jpadd(button_pause);

jpadd(button_resume);

//--- 开始按钮只执行一次 ---

button_startaddActionListener(new ActionListener() {

@Override

public void actionPerformed(ActionEvent ae) {

if (null == startThread) {

startThread = new Thread(a);

startThreadstart();

}

}

});

//--- 暂停按钮 ，按下后如果没有按继续，就不改变标志 ---

button_pauseaddActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

if (aisFlag() != false) {

asetFlag(false);

}

}

});

//--- 恢复按钮，这个最关键，主要是用notify()让线程继续执行，---

button_resumeaddActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

if (aisFlag() == false) {

asetFlag(true);

synchronized (a) {//--- 如果不放在同步快里，无法实现唤醒 ---

anotify();//--- 这个代码执行完后，a对象锁就释放了 所以process() 方法里德 notify()可不用---

}

}

}

});

cadd(jp,BorderLayoutNORTH);

cadd(a, BorderLayoutCENTER);

}

//--- 入口 ---

public static void main(String[] args) {

ThreadControll tc = new ThreadControll("test");

tcsetSize(400, 200);

tcsetVisible(true);

tcsetDefaultCloseOperation(JFrameEXIT_ON_CLOSE);

}

}

你建立了JPanel，但是没有把JPanel添加到JFrame中。

在HeadLine构造函数中添加：

thisadd(pane);

thissetVisible(true);

就ok了。

程序有点简陋，不过功能倒是全部实现了，你自己看吧

有些参数你自己可以调整

//这个程序哎，以后有机会再改进吧，至少坐标的移动我写的太烦了，可以直接指定的，擦

import javaawtBorderLayout;

import javaawtColor;

import javaawtEventQueue;

import javaawtGraphics;

import javaawtGraphics2D;

import javaawtgeomLine2D;

import javaawtgeomPoint2D;

import javaxswingJComponent;

import javaxswingJFrame;

public class JFrame1 extends JFrame {

private JPanel1 jp;

public static void main(String[] args) {

EventQueueinvokeLater(new Runnable() {

public void run() {

try {

JFrame1 frame = new JFrame1();

} catch (Exception e) {

eprintStackTrace();

}

}

});

}

public JFrame1() {

jp = new JPanel1();

jpsetBackground(ColorBLACK);

setDefaultCloseOperation(JFrameEXIT_ON_CLOSE);

getContentPane()setLayout(new BorderLayout(0, 0));

thissetBackground(ColorBLACK);

thissetContentPane(jp);

thissetSize(800, 600);

thissetLocationRelativeTo(null);

thissetVisible(true);

}

}

class JPanel1 extends JComponent{

int width,height;

int zx,zy;

int unit = 100; //单位长度包含的像素，也可考虑分别设置x，y轴的单位长度像素

public void paintComponent(Graphics g){

gsetColor(ColorBLACK);

width = thisgetWidth();

height = thisgetHeight();

// zx = 100;

// zy = 200;

zx = width/2; //新坐标系原点坐标位置，可以改变

zy = height/2;

gsetColor(ColorBLACK);

thispaintAxis(g);

thispaintMethod(g);

thispaintMethod1(g);

thispaintMethod2(g);

}

private void paintMethod(Graphics g1){

Point2D temp1,temp2;

double x,y;

Graphics2D g = (Graphics2D)g1;

gsetColor(ColorGREEN);

x = -10zx/unit;

y = Mathpow(x, 3) ;

temp1 = new Point2DDouble(thisalterX(x unit), thisalterY(y unit));

for(int i = 0 ; i < width; i++){

x += 10/unit;

y = Mathpow(x, 3) ;

if ( Mathabs(y) < zy){

temp2 = new Point2DDouble(thisalterX(x unit), thisalterY(y unit));

gdraw(new Line2DDouble(temp1, temp2));

temp1 = temp2;

}

}

}

private void paintMethod1(Graphics g1){

Point2D temp1,temp2;

double x,y;

Graphics2D g = (Graphics2D)g1;

gsetColor(ColorBLUE);

x = -10zx/unit;

y = Mathpow(MathE, x) ;

temp1 = new Point2DDouble(thisalterX(x unit), thisalterY(y unit));

for(int i = 0 ; i < width; i++){

x += 10/unit;

y = Mathpow(MathE, x) ;

if ( Mathabs(y) < zy){

temp2 = new Point2DDouble(thisalterX(x unit), thisalterY(y unit));

gdraw(new Line2DDouble(temp1, temp2));

temp1 = temp2;

}

}

}

private void paintMethod2(Graphics g1){

Point2D temp1,temp2;

double x,y;

Graphics2D g = (Graphics2D)g1;

gsetColor(ColorPINK);

x = -10zx/unit;

y = Mathsin(MathPI x);

temp1 = new Point2DDouble(thisalterX(x unit), thisalterY(y unit));

for(int i = 0 ; i < width; i++){

x += 10/unit;

y = Mathsin(MathPI x);

if ( Mathabs(y) < zy){

temp2 = new Point2DDouble(thisalterX(x unit), thisalterY(y unit));

gdraw(new Line2DDouble(temp1, temp2));

temp1 = temp2;

}

}

}

//画坐标轴,可以通过zx,zy的处置来改变原点位置;

private void paintAxis(Graphics g){

gsetColor(ColorCYAN);

gdrawLine(0, zy, width, zy);

gdrawLine(zx, 0, zx, height);

gdrawString("0",zx + 2,zy +12); //画原点数字

for(int i = 1; iunit < width; i++){

gdrawLine(zx + iunit, zy - 10, zx + iunit, zy);//x 正向

gdrawLine(zx - iunit, zy - 10, zx - iunit, zy);//x 负向

gdrawString(StringvalueOf(i), zx + iunit -3, zy + 12); // x轴数字

gdrawString(StringvalueOf(i -1), zx - iunit -8, zy + 12); // x轴数字

gdrawLine(zx , zy + iunit, zx + 10, zy + iunit);//y 负向

gdrawLine(zx , zy - iunit, zx + 10, zy - iunit);//y 正向

gdrawString(StringvalueOf(i), zx -12 , zy - iunit + 5); // y轴数字

gdrawString(StringvalueOf(i -1), zx -12 , zy + iunit + 5); // y轴数字

}

}

private double alterX(double x){ //新坐标对应的原坐标

return x + zx;

}

private double alterY(double y){ //新坐标对应的原坐标

return -1 ( y - zy);

}

}