I'm trying to change a textView from my thread, but it always crashes. Why?
public void startProgress(View view) {
bar.setProgress(0);
new Thread(new Task()).start();
}
class Task implements Runnable {
#Override
public void run() {
for (int i = 0; i <= 10; i++) {
final int value = i;
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
bar.setProgress(value);
text.setText("i = "+i);
}
}
}
I don't know why i can't change it. Anyone knows why?
Thanks.
Views can only be modified by their parent thread. This is a common problem that people face, unfortunately you just have to work around it.
Use runOnUiThread
runOnUiThread(new Runnable(){
public void run() {
for (int i = 0; i <= 10; i++) {
final int value = i;
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
bar.setProgress(value);
text.setText("i = "+i);
}
}
});
As #dodo or #CommonsWare said you must access View hiearhcy in the main ui thread.
To comply with this rule, use Handler.post(Context.getMainLooper())
new Handler(context.getMainLooper()).post(new Runnable() {
public void run() {
bar.setProgress(value);
text.setText("i = "+i);
}
});
Finally I fixed it. Thanks anyway.
public void startProgress(View view) {
bar.setProgress(0);
//new Thread(new Task()).start();
Thread th = new Thread(new Runnable() {
public void run() {
for (int i=0; i<10;i++){
final int timer = i;
runOnUiThread(new Runnable() {
#Override
public void run() {
text.setText("velocitat: "+timer);
}
});
bar.setProgress(timer);
try {
Thread.sleep(1000);
}
catch (InterruptedException e) {
e.printStackTrace();
}
}
}
});
th.start();
}
Related
I have tried updating my user interface using the text view what i have done is a run a while loop indefinitely and left the thread for sleep for one second..
int i;
while(true)
{
Thread.Sleep(1000);
textView.setText(updateTime);
}
Use runOnUiThread and surround with try catch for Thread.sleep(1000)
int i;
while(true)
{
try {
Thread.sleep(1000);
runOnUiThread(new Runnable() {
#Override
public void run() {
// TODO Auto-generated method stub
textView.setText(updateTime);
}
});
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
Try this one arnab...
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final TextView textView = (TextView) findViewById(R.id.displayid);
handler = new Handler() {
#Override
public void handleMessage(Message msg) {
bundle = msg.getData();
textView.setText(bundle.getString("mKey"));
}
};
}
public void press(View v) {
new Thread(new Runnable() {
#Override
public void run() {
while (true) {
synchronized (this) {
try {
wait(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
bundle = new Bundle();
message = handler.obtainMessage();
simpleDateFormat = new SimpleDateFormat("hh:mm:ss YYYY/mm/dd", Locale.US);
date = simpleDateFormat.format(new Date());
bundle.putString("mKey", date);
message.setData(bundle);
handler.sendMessage(message);
}
}
}
}).start();
}
Try runOnUiThread:
runOnUiThread(new Runnable() {
#Override
public void run() {
textView.setText(updateTime);
}
});
I have Runnable and have two Handlers for button background color change after some music is played.
Now how can I stop the music played using runnable for a ever delay of 700 mili sec on a button click named stop.
handler=new Handler();
runnable = new Runnable() {
#Override
public void run() {
for (int i = 0; i<Uirkeys1.length; i++) {
final int value = i;
try {
Thread.sleep(700);
} catch (InterruptedException e) {
e.printStackTrace();
}
handler.post(new Runnable() {
#Override
public void run() {
copyView.get(cnt1).getBackground().setAlpha(100);
ModeSound(Integer.parseInt(CopyMultimap.get(copykey[cnt1]).get(3)));
}
});
try {
Thread.sleep(800);
} catch (InterruptedException e) {
e.printStackTrace();
}
handler.post(new Runnable() {
#Override
public void run()
copyView.get(cnt1).getBackground().setAlpha(500);
cnt1++;
}
});
}
}
};
new Thread(runnable).start();
cnt1=0;
}
});
}
You could create a class MyRunnable that implements Runnable, and create a field in it
private boolean stopped = false;
public void stop() { stopped = true; }
And then you should check in your execution loop
if(!stopped) {..do work..} else return .
And you can of course call the stop() method on your MyRunnable object.
public class MainActivity extends Activity implements Runnable{
private int progressBarStatus = 0;
private Handler progressBarHandler = new Handler();
ProgressBar linProgressBar;
private long fileSize = 0;
Thread t1;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button b1 = (Button)findViewById(R.id.button1);
Button b2 = (Button)findViewById(R.id.button2);
b2.setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View arg0)
{
linProgressBar.setProgress(0);
t1.interrupt();
}
});
b1.setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View arg0)
{
basicInitializations();
}
});
}
public void basicInitializations(){
linProgressBar = (ProgressBar) findViewById(R.id.progressBar1);
linProgressBar.setProgress(0);
linProgressBar.setMax(100);
try{
t1 = new Thread()
{
public void run() {
while (progressBarStatus < 100) {
// process some tasks
progressBarStatus = doSomeTasks();
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
// Update the progress bar
progressBarHandler.post(new Runnable() {
public void run() {
linProgressBar.setProgress(progressBarStatus);
}
});
}
if (progressBarStatus >= 100) {
try {
Thread.sleep(2000);
} catch (InterruptedException e)
{
e.printStackTrace();
}
}
}
};
t1.start();
}catch (Exception e) {
}
}
public int doSomeTasks() {
while (fileSize <= 1000000) {
fileSize++;
if (fileSize == 100000) {
return 10;
} else if (fileSize == 200000) {
return 20;
} else if (fileSize == 300000) {
return 30;
}else if (fileSize == 400000) {
return 40;
}else if (fileSize == 500000) {
return 50;
}
}
return 100;
}
#Override
public void run() {
// TODO Auto-generated method stub
}
}
this is my main code and i could not stop this thread .
i want to stop it when i click the button b2(say cancel button).
the above code is not the original code and is a model , so please tell me how to stop that thread .
thankyou in advance . . . .
I have a alternate answer can try the same, inside your runnable loop always check a flag as run_flag, create it as a member variable and set it as true once you stared the loop, you can make it run_flag as false wenever you are done and at the same time you can set null to your thread also ... a safer way to come out through runnable loop and thread.
try{
t1 = new Thread()
{
public void run() {
while (progressBarStatus < 100 && run_flag == true) { // added run_flag here
// process some tasks
progressBarStatus = doSomeTasks();
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
// Update the progress bar
progressBarHandler.post(new Runnable() {
public void run() {
linProgressBar.setProgress(progressBarStatus);
}
});
}
if (progressBarStatus >= 100) {
try {
Thread.sleep(2000);
} catch (InterruptedException e)
{
e.printStackTrace();
}
}
}
};
t1.start();
}catch (Exception e) {
}
Your thread spends most of its time in Thread.sleep(), which is helpful. The thread pointer, t1, is a class member, which is also helpful. From your button handler, you can check to see if t1 is still alive and, if so, call t1.interrupt();. This will cause the thread's current sleep and future sleeps to throw the InterruptedException... now you just need to modify your exception handler to quit the thread in that case.
i try to make my screen blinking like this:
for (int i=0;i<10;i++)
{
targetView.setBackgroundColor(Color.BLUE);
for (int j=0;j<500;j++); //delay
targetView.setBackgroundColor(Color.RED);
}
but it wont work
Try this,
targetView.setBackgroundColor(Color.BLUE);
try {
Thread.sleep(5000); // milliseconds to wait...
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
targetView.setBackgroundColor(Color.RED);
EDIT
public class TSActivity extends Activity {
LinearLayout lin;
private int finalStatus = 0;
private Handler colorHandler = new Handler();
boolean flag = false;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
lin = (LinearLayout)findViewById(R.id.linMain);
new Thread(new Runnable() {
public void run() {
while (finalStatus < 100) {
// process some tasks
finalStatus = doSomeTasks();
try {
Thread.sleep(500);
} catch (InterruptedException e) {
e.printStackTrace();
}
// Update the color
colorHandler.post(new Runnable() {
public void run() {
if(flag)
{
lin.setBackgroundColor(Color.BLUE);
flag = false;
}
else
{
lin.setBackgroundColor(Color.GREEN);
flag = true;
}
}
});
}
}
}).start();
}
// color changer simulator... a really simple
public int doSomeTasks() {
long fileSize = 0;
while (fileSize <= 1000000) {
fileSize++;
if (fileSize == 100000) {
return 10;
} else if (fileSize == 200000) {
return 20;
} else if (fileSize == 300000) {
return 30;
}
// ...add your own
}
return 100;
}
}
Hope this will help you..
Thanks...
You can use handler also.
Runnable r=new Runnable(){
public void run(){
if(red){
targetView.setBackgroundColor(Color.RED);
red=false;
}
else{
targetView.setBackgroundColor(Color.BLUE);
red=true;
}
if(!stop_blinking) handler.postDelayed(this,1000);
}
};
handler=new Handler();
handler.postDelayed(r,1000); //1000 is in mili secs.
stop_blinking is boolean which you need to set whenever you want the view to stop blinking.
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
final ThraedDemo objDemo = new ThraedDemo();
Thread objThread = new Thread() {
#Override
public void run() {
objDemo.firstMethod();
}
};
objThread.start();
}
class ThraedDemo {
private void firstMethod() {
Thread objThread = new Thread() {
#Override
public void run() {
try {
((ImageView)findViewById(R.id.ImageViewnumber)).setImageResource(nums[n]);
Thread.sleep(10000);
Log.v("Thread","1111111111111111sleep");
} catch (InterruptedException ex) {
System.out.println("interuped exception" + ex.getMessage());
}
secondMethod();
}
private void secondMethod() {
Thread objThread = new Thread() {
#Override
public void run() {
try {
((ImageView)findViewById(R.id.ImageViewResult)).setImageResource(nums[n+1]);
n++;
Thread.sleep(10000);
Log.v("Thread","22222222222 sleep");
} catch (InterruptedException ex) {
System.out.println("interuped exception" + ex.getMessage());
}
firstMethod();
}
};
objThread.start();
}
};
objThread.start();
}
}
I use the above code but it is not running.it got CalledFromWrongThreadException what is the problem inb the above code.Please give me some suggestions.Thanks in advance
I think you can't do view modifications from another thread than the UI thread, so either create handlers in the oncreate and post your thread to it, or use AsyncTask, or runOnUIThread method to send portions of code directly to the UI thread.
I edited your 2nd function code, I see your code is loop forever cause the firstMethod call secondMethod and the secondMethod call the new firstMethod to start and then loop forever. I removed it and moved the code update ImageView into the UI Thread, could you try this:
class ThraedDemo {
private void firstMethod() {
Thread objThread = new Thread() {
#Override
public void run() {
try {
runOnUiThread(new Runnable() {
public void run(){
((ImageView)findViewById(R.id.ImageViewnumber)).setImageResource(nums[n]);
}
});
Thread.sleep(10000);
Log.v("Thread","1111111111111111sleep");
} catch (InterruptedException ex) {
System.out.println("interuped exception" + ex.getMessage());
}
secondMethod();
}
};
objThread.start();
}
private void secondMethod() {
Thread objThread2 = new Thread() {
#Override
public void run() {
try {
runOnUiThread(new Runnable() {
public void run(){
((ImageView)findViewById(R.id.ImageViewnumber)).setImageResource(nums[n+1]);
}
});
n++;
Thread.sleep(10000);
Log.v("Thread","22222222222 sleep");
} catch (InterruptedException ex) {
System.out.println("interuped exception" + ex.getMessage());
}
}
};
objThread2.start();
}
}