Android Countdown Timer app crashes when the button is clicked

Question

I've just started coding in Android SDK and this is my first attempt at a Countdown Timer. I've set the timer to start at the press of the button with setOnClickListener(). The timer doesn't start but the app stops working when I click the button. The device displays a message saying the app has stopped working.

I've written a method to format the time into minutes and seconds. And i've set the call in the onTick() method of the CountDownTimer.

I've posted my code below. Please take a look and point me to where the problem is and what to do. Much appreciated.

package com.example.day1;

import android.app.Activity;
import android.os.Bundle;
import android.os.CountDownTimer;
import android.view.View;
import android.widget.Button; 
import android.widget.TextView;
public class MainActivity extends Activity {


TextView Timer;//Textview to display the timer
    //This is the method to format the time into minutes and seconds 
public String formatTime(long millis)
{
    String output="00:00";
    long second=millis/1000;
    long minute=second/60;
    second=second%60;
    minute=minute%60;
    String sec=String.valueOf(second);
    String min=String.valueOf(minute);
    output=min+":"+sec;
    return output;
}

@Override
 protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.countdown);
    Timer=(TextView) findViewById(R.id.text1);
    Button button1=(Button)findViewById(R.id.button1);
    button1.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {


    new CountDownTimer(60000,1000)
    {
        public void onTick(long millisUntilFinished){
    Timer.setText(formatTime(millisUntilFinished));
        }
    public void onFinish()
    {
        onStop();
    }
    }.start();
    }
         });
     }
         }

Please can you post your log cat? displaying error log here will help greatly. However it seems to me that it may be the Timer.setText() giving you the crash. Make sure it is recieving char sequence or string. — SuppressWarnings
That's not an answer but a comment : Don't call onStop() directly, call finish(). — Snicolas
@Szymon This is what the logcat says- [2013-12-08 17:00:01 - day1] Failed to install day1.apk on device '4e1001b163b273000': EOF [2013-12-08 17:00:01 - day1] java.io.IOException: EOF [2013-12-08 17:00:01 - day1] Launch canceled! — Adarsh

Michael Michael · Accepted Answer · 2015-11-11T22:30:04

(1) Your app crash because you do not implements your activity with OnClickListener: you need to extend the method of your activity onclicklistener evet

Here is the code

package com.example.day1;

import android.app.Activity;
import android.os.Bundle;
import android.os.CountDownTimer;
import android.view.View;
import android.widget.Button; 
import android.widget.TextView;

///////////////////The solution is fix here///////////////
public class MainActivity extends Activity implements View.OnClickListener {
///////////////////End of solution//////////

TextView Timer;//Textview to display the timer
    //This is the method to format the time into minutes and seconds 
public String formatTime(long millis)
{
    String output="00:00";
    long second=millis/1000;
    long minute=second/60;
    second=second%60;
    minute=minute%60;
    String sec=String.valueOf(second);
    String min=String.valueOf(minute);
    output=min+":"+sec;
    return output;
}

@Override
 protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.countdown);
    Timer=(TextView) findViewById(R.id.text1);
    Button button1=(Button)findViewById(R.id.button1);
    button1.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {


    new CountDownTimer(60000,1000)
    {
        public void onTick(long millisUntilFinished){
    Timer.setText(formatTime(millisUntilFinished));
        }
    public void onFinish()
    {
        onStop();
    }
    }.start();
    }
         });
     }
         }

Android Countdown Timer app crashes when the button is clicked

1 Answers