We Keep Coding

delay inside while loop not working

i'm trying to make a delay inside while loop using Thread.sleep() method . here is my code :
new Thread(new Runnable() {
#Override
public void run() {
z=0;
while (z<45){
z++;
handler.post(new Runnable() {
#Override
public void run() {
time.setText(Integer.toString(45-z));
}
});
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}).start();
this code was working and suddenly a problem occurred . it started to make a delay less than one minute , sumtimes 500 ms and sumtimes less than that

Instead if using a different thread, Thread.sleep(), Handler and while loop you can try only with Handler like this,
private int timerCount = 0;
private static Handler myHandler = new Handler();
private void runVVRunnable() {
myHandler.postDelayed(runnable, 1000);
}
private Runnable runnable = new Runnable() {
#Override
public void run() {
timerCount++;
if ((time == null)) {
return;
}
if (timerCount <= 45) {
time.setText(Integer.toString(timerCount));
runVVRunnable();
}
}
};
#Override
protected void onDestroy() {
super.onDestroy();
myHandler.removeCallbacks(runnable);
}
you can just call runVVRunnable() it will do the same process which you are doing while loop

Just a guess but when sleeping/waiting on Java thread you need to try-catch InterruptedException.
This exception is thrown when "someone" calls interrupt() on your thread.
This will cause the thread to wake up from sleep early than expected.
Check if you catch InterruptedException before your thread terminated.

cannot stop progress bar on Android using Thread.interrupt

I am running into a minor issue that I don't understand. I have a simple progress bar but Thread.interrupt does not stop the thread. I have to hack it a global variable. I wonder if anyone can stop the issue.
I tried this thread, but did not work for me:
How to stop a thread(progressbar) in android
here's the code with the hacks
// Start lengthy operation in a background thread
calcThread = new Thread
(
new Runnable()
{
public void run()
{
Thread current = Thread.currentThread();
//while (!current.isInterrupted()) // this does not
while (threadLoop) // this hack works
{
doWork();
try {
Thread.sleep(100);
} catch (InterruptedException e) {}
// Update the progress bar
mHandler.post(new Runnable() {
public void run() {
mProgress.setProgress(mProgressStatus);
}
});
}
Log.d(TAG, "out of thread loop");
}
}
);
calcThread.start();
now where I try to stop the thread
public void onClickAbout(View view)
{
if (view.getId() == R.id.buttonAbout)
{
Log.d(TAG, "onButtonPressed");
calcThread.interrupt(); // This does not work
threadLoop = false; // this works.
}
}
Why do I have to hack a global? In other words, why Thread.interrupt does not stop the thread.
thx!

Why don't you try the following
Thread background = new Thread() {
public void run() {
try{
for(int s=0;s<=100;s++)
{
s=s+20;
sleep(1000);
progressbar.setProgress(s);
}
}catch(InterruptedException e){
e.printStackTrace();
}finally{
//do some thing after you finish thread
}
}
};
background.start();

It doesn't work because you're catching InterruptedException and ignoring it. The thread is no longer interrupted after the exception is thrown. (See this Q&A.) But k0sh is right, you should use an AsyncTask.

I need to stop thread when progress bar reaches 0 in android

I need stop thread and handler when my progress bar reaches 0 from 100 when thread runs the progress bar reaches but the progressStatus value going in negative please help me to stop thread after progress bar reaches 0
new Thread(runn =new Runnable() {
public void run() {
while (progressStatus <= 100) {
progressStatus += doWork();
try {
Thread.sleep(10);
} catch (InterruptedException e) {
e.printStackTrace();
}
// Update the progress bar
handler.post(runn1=new Runnable() {
public void run() {
bar.setProgress(progressStatus);
i=-1;
if(bar.getProgress()==0)
{
handler.removeCallbacks(runn);
handler.removeCallbacks(runn1);
System.out.println("Reached");
congrats.setVisibility(View.VISIBLE);
restart.setVisibility(View.VISIBLE);
rightbutton.setVisibility(View.GONE);
wrongbutton.setVisibility(View.GONE);
}
}
});
}
}
private int doWork() {
return i;
}
}).start();

your program is not thread safe, you actually reading and writing a variable (progressStatus) from two different threads, you must avoid doing that or if you want to do that you must use synchronized block. In order to solve your problem you can do this way:
Thread t;
progressStatus = 100;
t = new Thread(runn =new Runnable() {
public void run() {
while (!Thread.currentThread().isInterrupted()) {
try {
Thread.sleep(10);
} catch (InterruptedException e) {
e.printStackTrace();
return;
}
// Update the progress bar
handler.post(runn1=new Runnable() {
public void run() {
bar.setProgress(progressStatus);
progressStatus=progressStatus-1;
if(bar.getProgress()==0)
{
handler.removeCallbacks(runn);
handler.removeCallbacks(runn1);
System.out.println("Reached");
congrats.setVisibility(View.VISIBLE);
restart.setVisibility(View.VISIBLE);
rightbutton.setVisibility(View.GONE);
wrongbutton.setVisibility(View.GONE);
t.interrupt();
}
}
});
another way that i recommend you is using ScheduledThreadPoolExecutor with the function scheduleAtFixedRate(Runnable command, long initialDelay, long period, TimeUnit unit). something like:
final ScheduledThreadPoolExecutor myTimer = new ScheduledThreadPoolExecutor(1);
myTimer.scheduleAtFixedRate(new Runnable() {
#Override
public void run() {
getActivity().runOnUiThread(new Runnable(){
#Override
public void run(){
}
});
}
}
}, 0,10, TimeUnit.MILLISECONDS);
and in order to close it use myTimer.shutdownNow();

Thread in android not working as expected

I am following a guide that shows how to create a Pong game. There is a part, where I am supposed to create a Thread, and call a function that moves the ball.
This is the code I created:
package com.ozadari.pingpong;
public class PingPongGame extends Thread {
private Ball gameBall;
private PingPongView gameView;
public PingPongGame(Ball theBall,PingPongView mainView)
{
this.gameBall = theBall;
this.gameView = mainView;
}
#Override
public void run()
{
while(true)
{
this.gameBall.moveBall();
this.gameView.postInvalidate();
try
{
PingPongGame.sleep(5);
}
catch(InterruptedException e)
{
e.printStackTrace();
}
}
}}
The thread is called and working, but it doesn't print anything. I tried to cancel the infinte loop and make the loop run 100 times. After I wait a while, it prints to the screen as it should be after 100 runs, but it doesn't print anything in the middle.
What is the problem? How can I fix it?

Unsure from the code you've posted but anyway, you can use a handler and have it run once every second like so (change the time to what you want):
Handler handler = new Handler();
final Runnable r = new Runnable()
{
public void run()
{
//do your stuff here
handler.postDelayed(this, 1000);
}
};
handler.postDelayed(r, 1000);
http://developer.android.com/reference/android/os/Handler.html
You can also use a normal thread, and call start at the end.
Thread thread = new Thread()
{
#Override
public void run() {
try {
while(true) {
sleep(1000);
handler.post(r);
}
} catch (InterruptedException e) {
e.printStackTrace();
}
}
};
thread.start();

Java parallel threading

public class Signal2NoiseRatio
{
public ImagePlus SingleSNR(ImagePlus imagePlus) throws InterruptedException
{
new Thread()
{
#Override public void run()
{
JFrame imageFrame = new JFrame("ROI");
Container imageFrame_Container = imageFrame.getContentPane();
IIImagePanel imagePanel = new IIImagePanel();
imageFrame_Container.add(imagePanel);
imagePanel.setImage(imagePlus.getImage());
imagePanel.getDisplayedImage();
imageFrame.setVisible(true);
final SNRSingleImageListener sNRSingleListener = new SNRSingleImageListener(imagePanel);
imagePanel.addMouseListener(sNRSingleListener);
imagePanel.addMouseMotionListener(sNRSingleListener);
}
}.start();
new Thread()
{
#Override public void run()
{
for (int i = 0; i <= 2000; i++)
{
System.out.println("schleife "+i);
// ask if useractions are done ..
}
synchronized( Signal2NoiseRatio.this )
{
Signal2NoiseRatio.this.notifyAll();
}
}
}.start();
synchronized (this)
{
this.wait();
// if userinteractions are done, go on
}
return imagePlusToProcess;
}
}
The first new Thread() perform a frame which presents an image in it. My intention was to present the image in a new thread to wait for some user interactions on the image. But the code leads the frame to a white window and the image is not visible and the frame is not usable.
In the second thread I want ask in a short interval if the user actions are done.
It is not really a nice solution but it is be possible? what's wrong here?
Thank you stackoverflow!

I can see a few problems here:
1.If this
synchronized (this)
{
this.wait();
// if userinteractions are done, go on
}
is happening on the UI thread, then you will block it from receiving user input (or doing anything else) until the object is signaled.
2.This part seems pretty much overcomplicated:
new Thread() {
#Override
public void run() {
for (int i = 0; i <= 2000; i++) {
System.out.println("schleife " + i);
// ask if useractions are done ..
}
synchronized (Signal2NoiseRatio.this) {
Signal2NoiseRatio.this.notifyAll();
}
}
}.start();
synchronized (this) {
this.wait();
// if userinteractions are done, go on
}
Just use:
Thread t = new Thread() {
#Override
public void run() {
for (int i = 0; i <= 2000; i++) {
System.out.println("schleife " + i);
// ask if useractions are done ..
}
}
}.start();
t.join();
Unless you're signaling more than what you had above. But again, this is redundant, since starting a thread only to wait for it to finish does not make much sense...

Problem solved.
The invoker of the method was an AWT-Thread. I created a new Thread for the invoker and so the AWT-Thread was not blocked and the then frame and image could present correctly.
Thank you all for your help.