Progress bar with thread - android-progressbar

Question

Now a days it's my first step in android. I am simply trying to implement progress bar with with a "Download" Button. When i press download button progress bar keep on progressing but when the whole progress gets over i am not able to hide progress bar. Here is my code. please help me.
public class ProgressBarDemo extends Activity
{
ProgressBar pb;
Button bt;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.progressbar);
pb = (ProgressBar) findViewById(R.id.progressBar1);
bt = (Button) findViewById(R.id.button1);
pb.setVisibility(View.VISIBLE);
bt.setOnClickListener(new OnClickListener()
{
public void onClick(View v)
{
Thread timer = new Thread()
{
public void run()
{
try
{
for(int i=0; i<=50; i ++)
{
pb.incrementProgressBy(i);
sleep(1000);
}
pb.setVisibility(View.INVISIBLE);
Toast.makeText(ProgressBarDemo.this, "Thank you for downloading", Toast.LENGTH_SHORT).show();
}catch(Exception e){}
}
};
timer.start();
}
});
}
}

Answer 1

You should only modifiy ui elements from the mainThread (the UI Thread) try
pb.post(new Runnable() {
#Override
public void run() {
pb.setVisibility(View.INVISIBLE);
}
})
instead.
Maybe u have to use the same thing for incrementing your progressbar. Alternativley you could use the AsyncTask http://developer.android.com/reference/android/os/AsyncTask.html class. onProgressUpdate and onPostExecute are called in the UIThread automatically.

Answer 2

you can also use AsynTask that is a better solution...
public class ProgressBarDemo extends Activity
{
ProgressBar pb;
Button bt;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
pb = (ProgressBar) findViewById(R.id.progressBar1);
bt = (Button) findViewById(R.id.button1);
pb.setVisibility(View.VISIBLE);
bt.setOnClickListener(new OnClickListener()
{
public void onClick(View v)
{
new AsynTasks().execute();
}
});
}
class AsynTasks extends AsyncTask<Void, Integer, Void>
{
#Override
protected Void doInBackground(Void... params) {
for(int i=1;i<=100;i++)
{
SystemClock.sleep(1000);
publishProgress(i);
}
return null;
}
#Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
pb.setVisibility(View.INVISIBLE);
Toast.makeText(ProgressBarDemo .this, "Thank you for downloading", Toast.LENGTH_SHORT).show();
}
#Override
protected void onProgressUpdate(Integer... values) {
super.onProgressUpdate(values);
pb.setProgress(values[0]);
}
}
}

Answer 3

You should not do UI task from different thread.Use this...
public class ProgressBarDemo extends Activity
{
ProgressBar pb;
Button bt;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
pb = (ProgressBar) findViewById(R.id.progressBar1);
bt = (Button) findViewById(R.id.button1);
pb.setVisibility(View.VISIBLE);
bt.setOnClickListener(new OnClickListener()
{
public void onClick(View v)
{
Thread timer = new Thread()
{
public void run()
{
try
{
for(int i=1; i<=100; i ++)
{
pb.setProgress(i);
sleep(100);
}
}catch(Exception e){}
finally{
runOnUiThread( new Runnable() {
public void run() {
pb.setVisibility(View.INVISIBLE);
Toast.makeText(ProgressBarDemo .this, "Thank you for downloading", Toast.LENGTH_SHORT).show();
}
});
}
}
};
timer.start();
}
});
}
}