How to make a countdown timer in Android?

问题:

I have two EditTexts in XML. In one EditText, the user can put a number as minutes and in another EditText, a number as seconds. After clicking the finish button, the seconds EditText should start to countdown and update its text every second.

Additionally, how can I keep it updating until it gets to zero minutes and zero seconds?

回答1:

new CountDownTimer(30000, 1000) {

    public void onTick(long millisUntilFinished) {
        mTextField.setText(\"seconds remaining: \" + millisUntilFinished / 1000);
       //here you can have your logic to set text to edittext
    }

    public void onFinish() {
        mTextField.setText(\"done!\");
    }

}.start();

Refer to this link.

回答2:

if you use the below code (as mentioned in accepted answer),

new CountDownTimer(30000, 1000) {

    public void onTick(long millisUntilFinished) {
        mTextField.setText(\"seconds remaining: \" + millisUntilFinished / 1000);
       //here you can have your logic to set text to edittext
    }

    public void onFinish() {
        mTextField.setText(\"done!\");
    }

}.start();

It will result in memory leak of the instance of the activity where you use this code, if you don\'t carefully clean up the references.

use the following code

//Declare timer
CountDownTimer cTimer = null;

//start timer function
void startTimer() {
    cTimer = new CountDownTimer(30000, 1000) {
        public void onTick(long millisUntilFinished) {
        }
        public void onFinish() {
        }
    };
    cTimer.start();
}


//cancel timer
void cancelTimer() {
    if(cTimer!=null)
        cTimer.cancel();
}

You need to call cTtimer.cancel() whenever the onDestroy()/onDestroyView() in the owning Activity/Fragment is called.

回答3:

MainActivity.java

package com.zeustechnocrats.countdown;

import android.os.Bundle;
import android.os.Handler;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.LinearLayout;
import android.widget.TextView;

import java.text.SimpleDateFormat;
import java.util.Date;

public class MainActivity extends AppCompatActivity {

    private String EVENT_DATE_TIME = \"2018-12-31 10:30:00\";
    private String DATE_FORMAT = \"yyyy-MM-dd HH:mm:ss\";
    private LinearLayout linear_layout_1, linear_layout_2;
    private TextView tv_days, tv_hour, tv_minute, tv_second;
    private Handler handler = new Handler();
    private Runnable runnable;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.count_down);

        initUI();
        countDownStart();
    }

    private void initUI() {
        linear_layout_1 = findViewById(R.id.linear_layout_1);
        linear_layout_2 = findViewById(R.id.linear_layout_2);
        tv_days = findViewById(R.id.tv_days);
        tv_hour = findViewById(R.id.tv_hour);
        tv_minute = findViewById(R.id.tv_minute);
        tv_second = findViewById(R.id.tv_second);
    }

    private void countDownStart() {
        runnable = new Runnable() {
            @Override
            public void run() {
                try {
                    handler.postDelayed(this, 1000);
                    SimpleDateFormat dateFormat = new SimpleDateFormat(DATE_FORMAT);
                    Date event_date = dateFormat.parse(EVENT_DATE_TIME);
                    Date current_date = new Date();
                    if (!current_date.after(event_date)) {
                        long diff = event_date.getTime() - current_date.getTime();
                        long Days = diff / (24 * 60 * 60 * 1000);
                        long Hours = diff / (60 * 60 * 1000) % 24;
                        long Minutes = diff / (60 * 1000) % 60;
                        long Seconds = diff / 1000 % 60;
                        //
                        tv_days.setText(String.format(\"%02d\", Days));
                        tv_hour.setText(String.format(\"%02d\", Hours));
                        tv_minute.setText(String.format(\"%02d\", Minutes));
                        tv_second.setText(String.format(\"%02d\", Seconds));
                    } else {
                        linear_layout_1.setVisibility(View.VISIBLE);
                        linear_layout_2.setVisibility(View.GONE);
                        handler.removeCallbacks(runnable);
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        };
        handler.postDelayed(runnable, 0);
    }

    protected void onStop() {
        super.onStop();
        handler.removeCallbacks(runnable);
    }
}

activity_main.xml

    <LinearLayout xmlns:android=\"http://schemas.android.com/apk/res/android\"
    android:layout_width=\"match_parent\"
    android:layout_height=\"match_parent\"
    android:background=\"@android:color/white\"
    android:orientation=\"horizontal\">

    <LinearLayout
        android:id=\"@+id/linear_layout_1\"
        android:layout_width=\"match_parent\"
        android:layout_height=\"wrap_content\"
        android:background=\"@android:color/black\"
        android:gravity=\"center_horizontal\"
        android:visibility=\"gone\">

        <TextView
            android:id=\"@+id/tv_event\"
            android:layout_width=\"wrap_content\"
            android:layout_height=\"wrap_content\"
            android:layout_margin=\"20dp\"
            android:text=\"Android Event Start\"
            android:textColor=\"@android:color/white\"
            android:textSize=\"20dp\"
            android:textStyle=\"normal\" />
    </LinearLayout>

    <LinearLayout
        android:id=\"@+id/linear_layout_2\"
        android:layout_width=\"match_parent\"
        android:layout_height=\"wrap_content\"
        android:background=\"@android:color/black\"
        android:visibility=\"visible\">

        <LinearLayout
            android:layout_width=\"match_parent\"
            android:layout_height=\"wrap_content\"
            android:layout_weight=\"1\"
            android:orientation=\"vertical\">

            <TextView
                android:id=\"@+id/tv_days\"
                android:layout_width=\"wrap_content\"
                android:layout_height=\"wrap_content\"
                android:layout_gravity=\"center\"
                android:text=\"00\"
                android:textColor=\"@android:color/white\"
                android:textSize=\"20dp\"
                android:textStyle=\"bold\" />

            <TextView
                android:id=\"@+id/tv_days_title\"
                android:layout_width=\"wrap_content\"
                android:layout_height=\"wrap_content\"
                android:layout_gravity=\"center\"
                android:text=\"Days\"
                android:textColor=\"@android:color/white\"
                android:textSize=\"20dp\"
                android:textStyle=\"normal\" />
        </LinearLayout>

        <LinearLayout
            android:layout_width=\"match_parent\"
            android:layout_height=\"wrap_content\"
            android:layout_weight=\"1\"
            android:orientation=\"vertical\">

            <TextView
                android:id=\"@+id/tv_hour\"
                android:layout_width=\"wrap_content\"
                android:layout_height=\"wrap_content\"
                android:layout_gravity=\"center\"
                android:text=\"00\"
                android:textColor=\"@android:color/white\"
                android:textSize=\"20dp\"
                android:textStyle=\"bold\" />

            <TextView
                android:id=\"@+id/tv_hour_title\"
                android:layout_width=\"wrap_content\"
                android:layout_height=\"wrap_content\"
                android:layout_gravity=\"center\"
                android:text=\"Hour\"
                android:textColor=\"@android:color/white\"
                android:textSize=\"20dp\"
                android:textStyle=\"normal\" />
        </LinearLayout>

        <LinearLayout
            android:layout_width=\"match_parent\"
            android:layout_height=\"wrap_content\"
            android:layout_weight=\"1\"
            android:orientation=\"vertical\">

            <TextView
                android:id=\"@+id/tv_minute\"
                android:layout_width=\"wrap_content\"
                android:layout_height=\"wrap_content\"
                android:layout_gravity=\"center\"
                android:text=\"00\"
                android:textColor=\"@android:color/white\"
                android:textSize=\"20dp\"
                android:textStyle=\"bold\" />

            <TextView
                android:id=\"@+id/tv_minute_title\"
                android:layout_width=\"wrap_content\"
                android:layout_height=\"wrap_content\"
                android:layout_gravity=\"center\"
                android:text=\"Minute\"
                android:textColor=\"@android:color/white\"
                android:textSize=\"20dp\"
                android:textStyle=\"normal\" />
        </LinearLayout>

        <LinearLayout
            android:layout_width=\"match_parent\"
            android:layout_height=\"wrap_content\"
            android:layout_weight=\"1\"
            android:orientation=\"vertical\">

            <TextView
                android:id=\"@+id/tv_second\"
                android:layout_width=\"wrap_content\"
                android:layout_height=\"wrap_content\"
                android:layout_gravity=\"center\"
                android:text=\"00\"
                android:textColor=\"@android:color/white\"
                android:textSize=\"20dp\"
                android:textStyle=\"bold\" />

            <TextView
                android:id=\"@+id/tv_second_title\"
                android:layout_width=\"wrap_content\"
                android:layout_height=\"wrap_content\"
                android:layout_gravity=\"center\"
                android:text=\"Second\"
                android:textColor=\"@android:color/white\"
                android:textSize=\"20dp\"
                android:textStyle=\"normal\" />
        </LinearLayout>
    </LinearLayout>
</LinearLayout>

回答4:

just copy paste the following code........

MainActivity

package com.example.countdowntimer;

import java.util.concurrent.TimeUnit;
import android.app.Activity;
import android.os.Bundle;
import android.os.CountDownTimer;
import android.widget.TextView;


public class MainActivity extends Activity {


      TextView text1;

 private static final String FORMAT = \"%02d:%02d:%02d\";

 int seconds , minutes;

@Override
public void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);


    text1=(TextView)findViewById(R.id.textView1);

    new CountDownTimer(16069000, 1000) { // adjust the milli seconds here

        public void onTick(long millisUntilFinished) {

            text1.setText(\"\"+String.format(FORMAT,
                    TimeUnit.MILLISECONDS.toHours(millisUntilFinished),
TimeUnit.MILLISECONDS.toMinutes(millisUntilFinished) - TimeUnit.HOURS.toMinutes(
                    TimeUnit.MILLISECONDS.toHours(millisUntilFinished)),
  TimeUnit.MILLISECONDS.toSeconds(millisUntilFinished) - TimeUnit.MINUTES.toSeconds(
                      TimeUnit.MILLISECONDS.toMinutes(millisUntilFinished))));              
        }

        public void onFinish() {
            text1.setText(\"done!\");
        }
     }.start();             

  }

  }

activity_main.xml

 <RelativeLayout xmlns:android=\"http://schemas.android.com/apk/res/android\"
 android:layout_width=\"match_parent\"
 android:layout_height=\"match_parent\"
 android:orientation=\"vertical\" >

<TextView
    android:id=\"@+id/textView1\"
    android:layout_width=\"wrap_content\"
    android:layout_height=\"wrap_content\"
    android:layout_alignParentLeft=\"true\"
    android:layout_alignParentTop=\"true\"
    android:layout_marginLeft=\"34dp\"
    android:layout_marginTop=\"58dp\"
    android:text=\"Large Text\"
    android:textAppearance=\"?android:attr/textAppearanceMedium\" />

   </RelativeLayout>

回答5:

Just Call below function by passing seconds and textview object

public void reverseTimer(int Seconds,final TextView tv){

    new CountDownTimer(Seconds* 1000+1000, 1000) {

        public void onTick(long millisUntilFinished) {
            int seconds = (int) (millisUntilFinished / 1000);
            int minutes = seconds / 60;
            seconds = seconds % 60;
            tv.setText(\"TIME : \" + String.format(\"%02d\", minutes)
                    + \":\" + String.format(\"%02d\", seconds));
        }

        public void onFinish() {
            tv.setText(\"Completed\");
        }
    }.start();
}

回答6:

Revers CountDown timer with hours minutes and seconds

public void reverseTimer(int Seconds, final TextView tv) {

    new CountDownTimer(Seconds * 1000 + 1000, 1000) {

        public void onTick(long millisUntilFinished) {
            int seconds = (int) (millisUntilFinished / 1000);

            int hours = seconds / (60 * 60);
            int tempMint = (seconds - (hours * 60 * 60));
            int minutes = tempMint / 60;
            seconds = tempMint - (minutes * 60);

            tv.setText(\"TIME : \" + String.format(\"%02d\", hours)
                    + \":\" + String.format(\"%02d\", minutes)
                    + \":\" + String.format(\"%02d\", seconds));
        }

        public void onFinish() {
            tv.setText(\"Completed\");
        }
    }.start();
}

回答7:

Using Kotlin:

var timer = object: CountDownTimer(30000, 1000) {
        override fun onTick(millisUntilFinished: Long) {
            tvTimer.setText(\"seconds remaining: \" + millisUntilFinished / 1000)
        }

        override fun onFinish() {
            tvTimer.setText(\"done!\")
        }
    }
timer.start()

回答8:

Try this way:

private void startTimer() {
    startTimer = new CountDownTimer(30000, 1000) {

        public void onTick(long millisUntilFinished) {

            long sec = (TimeUnit.MILLISECONDS.toSeconds(millisUntilFinished) -
 TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.toMinutes(millisUntilFinished)));

            Log.e(TAG, \"onTick: \"+sec );
            tv_timer.setText(String.format(\"( %02d SEC )\", sec));
            if(sec == 1)
            {

                new Handler().postDelayed(new Runnable() {
                    @Override
                    public void run() {
                        tv_timer.setText(\"( 00 SEC )\");
                    }
                }, 1000);
            }


        }

        public void onFinish() {
            tv_timer.setText(\"Timer finish\");
        }
    }.start();
}

回答9:

The Interface way.

import android.os.CountDownTimer;

/**
 * Created by saikiran on 07-03-2016.
 */
public class CountDownTimerCustom extends CountDownTimer {

    private TimeTickListener mTickListener;
    private TimeFinishListener mFinishListener;
    private long millisUntilFinished;

    public CountDownTimerCustom(long millisInFuture, long countDownInterval) {
        super(millisInFuture, countDownInterval);

    }

    public void updateTickAndFinishListener(TimeTickListener tickListener) {
        mTickListener = tickListener;
    }

    public void updateFinishListner(TimeFinishListener listener) {
        mFinishListener = listener;
    }

    public long getCurrentMs() {
        return millisUntilFinished;
    }

    public int getCurrentSec() {
        return (int) millisUntilFinished / 1000;
    }

    @Override
    public void onTick(long millisUntilFinished) {
        this.millisUntilFinished = millisUntilFinished;
        if (mTickListener != null)
            mTickListener.onTick(millisUntilFinished);
    }

    @Override
    public void onFinish() {
        if (mTickListener != null)
            mTickListener.onFinished();
        mFinishListener.onFinished();
    }


    public interface TimeTickListener {
        void onTick(long mMillisUntilFinished);

        void onFinished();
    }

    public interface TimeFinishListener {
        void onFinished();
    }
}