countdown timer in android.

Android Count Down Timer Example

In this sample application we will create a countdown timer in android using the CountDownTimerclass .This is an example of showing a 30 second countdown in a TextView . We will update the TextView on every tick of the timer.The option to stop and restart the timer is also provided.

So let us start:

1.Create a new project File ->New -> Project ->Android ->Android Application Project. While creating the new project, name the activity as TimerActivity(TimerActivity.java) and layout asactivity_timer.xml.

2.Now let us design the UI for the TimerActivity i.e activity_timer.xml with a textview and a button.

activity_timer.xml

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

android:orientation="vertical"

android:background="@drawable/bgi" >

<TextView

android:id="@+id/timer"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_centerHorizontal="true"

android:layout_centerVertical="true"

android:paddingRight="10dip"

android:textSize="50dp" />

<Button

android:id="@+id/button"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:layout_alignParentBottom="true"

android:layout_alignParentLeft="true"

android:text="Start" />

</RelativeLayout>

3.Now in the TimerActivity we implement the count down timer by extending the CountDownTimer class.Press Ctrl+Shift+O for missing imports after typing the code.

TimerActivity.java

public class TimerActivity extends Activity implements OnClickListener {

private CountDownTimer countDownTimer;

private boolean timerHasStarted = false;

private Button startB;

public TextView text;

private final long startTime = 30 * 1000;

private final long interval = 1 * 1000;

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_timer);

startB = (Button) this.findViewById(R.id.button);

startB.setOnClickListener(this);

text = (TextView) this.findViewById(R.id.timer);

countDownTimer = new MyCountDownTimer(startTime, interval);

text.setText(text.getText() + String.valueOf(startTime/1000));

}

@Override

public void onClick(View v) {

if (!timerHasStarted) {

countDownTimer.start();

timerHasStarted = true;

startB.setText("STOP");

} else {

countDownTimer.cancel();

timerHasStarted = false;

startB.setText("RESTART");

}

}

public class MyCountDownTimer extends CountDownTimer {

public MyCountDownTimer(long startTime, long interval) {

super(startTime, interval);

}

@Override

public void onFinish() {

text.setText("Time's up!");

}

@Override

public void onTick(long millisUntilFinished) {

text.setText("" + millisUntilFinished/1000);

}

}

}

4.Run the project by rightclicking project Run as → android project.

Output:

The output of this example would be similar to the one as follows: