如何在Android中制作倒计时器？

Question

在XML中我有两个EditText。在一个EditText中，用户可以输入分钟数，在另一个EditText中，可以输入秒数。在点击完成按钮后，秒EditText应开始倒计时并每秒更新其文本。

此外，如何使其保持更新直到达到零分钟和零秒？

- Sabbir Ahmed

---

可能是重复的问题，与 Android倒计时 相似。 - MByD

Answer 1

如 CountDownTimer 的文档所示：

new CountDownTimer(30000, 1000) {

    public void onTick(long millisUntilFinished) {
        mTextField.setText("seconds remaining: " + millisUntilFinished / 1000);
        // logic to set the EditText could go here
    }

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

}.start();

- anon

---

这是一个不错的回答，但有没有人能向我展示如何设置自定义倒计时时间，而不仅仅是输入30秒？我尝试从EditText中获取值，但似乎根本没有起作用。 - edwoollard

如果我想基于设置的闹钟来设置CountDownTimer，该怎么办？我如何知道还有多少毫秒才能完成？ - Kala J

你知道 CountdownTimer 是否有暂停方法吗？比如说用户想要暂停游戏，他们可以点击一个按钮来暂停倒计时器，当他们再次点击播放时，它会继续倒计时吗？ - James111

如果我设置一个24小时的定时器，一切都正常运行，但用户更改了设备时间，会发生什么？如何避免这种情况发生？ - undefined

Answer 2

如果您使用下面代码（如接受答案中所述），

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();

如果您不仔细清理引用，使用此代码的活动实例将导致内存泄漏。

请使用以下代码：

//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();
}

你需要在拥有的Activity/Fragment中的onDestroy()/onDestroyView()被调用时，调用cTtimer.cancel()。

- shanraisshan

---

是的！10/10。这应该是正确的答案。否则，即使您按BACK，countDownThread仍然在工作。您可以放置一个Log.i，您会看到它每1秒抛出信息，如果您不放置“.cancel()”。 - user3833732

在取消之前，有没有一种方法可以检查CountDownTimer是否仍在运行？ - CanCoder

检查计时器是否不为null。 - Abdulrahman Abdelkader

如果我设置一个24小时的定时器，但用户更改了设备时间，会发生什么？如何避免这种情况发生？@AbdulrahmanAbdelkader - undefined

Answer 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 = "2023-12-31 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>

- Sanjay Mangaroliya

---

为什么要使用 handler.postDelayed(runnable, 1 * 1000);？ - Kyryl Zotov

活动销毁后不要忘记清理计时器。否则可能会导致内存泄漏。 - Bugdr0id

handler.postDelayed(runnable, 0) = handler.post(runnable)handler.postDelayed（runnable，0）= handler.post（runnable） - Leo DroidCoder

如果有人想要添加时区，可以尝试这个优秀的解决方案：dateFormat.setTimeZone(TimeZone.getTimeZone("GMT+05:30")); - Asesha George

Answer 4

只需复制粘贴以下代码......

MainActivity

包名 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>

- gAuRaV jAiN

---

但是当我的手机锁定时，计时器会暂停，当我解锁后它会继续。我该怎么做才能让计时器持续运行呢？ - Shaktisinh Jadeja

请勿鼓励复制粘贴代码。提供文档和解释的链接会是更好的答案。 - mshukla

Answer 5

只需通过传递秒数和文本视图对象调用以下函数

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();
}

- Prashant Maheshwari Andro

---

捕获NPE的完美案例。 当Activity被销毁而计时器仍在运行时会发生什么？ - Barterio

Answer 6

带有小时、分钟和秒的倒计时器

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();
}

- tej shah

Answer 7

使用 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()

- Daniel Shterenberg

Answer 8

输出：01:30

new CountDownTimer(90000, 1000) {

            public void onTick(long duration) {
                //tTimer.setText("seconds remaining: " + millisUntilFinished / 1000);
                //here you can have your logic to set text to edittext resource id
                // Duration
                long Mmin = (duration / 1000) / 60;
                long Ssec = (duration / 1000) % 60;
                if (Ssec < 10) {
                    tTimer.setText("" + Mmin + ":0" + Ssec);
                } else tTimer.setText("" + Mmin + ":" + Ssec);
            }

            public void onFinish() {
                tTimer.setText("00:00");
            }

        }.start();

- Vikash Sharma

Answer 9

public class Scan extends AppCompatActivity {
int minute;
long min;
TextView tv_timer;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_scan2);
    tv_timer=findViewById(R.id.tv_timer);
    minute=Integer.parseInt("Your time in string form like 10");
    min= minute*60*1000;
    counter(min);
}
private void counter(long min) {
    CountDownTimer timer = new CountDownTimer(min, 1000) {
        public void onTick(long millisUntilFinished) {
            int seconds = (int) (millisUntilFinished / 1000) % 60;
            int minutes = (int) ((millisUntilFinished / (1000 * 60)) % 60);
            int hours = (int) ((millisUntilFinished / (1000 * 60 * 60)) % 24);
            tv_timer.setText(String.format("%d:%d:%d", hours, minutes, seconds));
        }
        public void onFinish() {
            Toast.makeText(getApplicationContext(), "Your time has been completed",
                    Toast.LENGTH_LONG).show();
        }
    };
    timer.start();
}

}

- Paramatma Sharan

Answer 10

var futureMinDate = Date()
val sdf = SimpleDateFormat("yyyy-MM-dd", Locale.ENGLISH)
try {
    futureMinDate = sdf.parse("2019-08-22")
} catch (e: ParseException) {
    e.printStackTrace()
}

// Here futureMinDate.time Returns the number of milliseconds since January 1, 1970, 00:00:00 GM
// So we need to subtract the millis from current millis to get actual millis
object : CountDownTimer(futureMinDate.time - System.currentTimeMillis(), 1000) {
    override fun onTick(millisUntilFinished: Long) {
        val sec = (millisUntilFinished / 1000) % 60
        val min = (millisUntilFinished / (1000 * 60)) % 60
        val hr = (millisUntilFinished / (1000 * 60 * 60)) % 24
        val day = ((millisUntilFinished / (1000 * 60 * 60)) / 24).toInt()
        val formattedTimeStr = if (day > 1) "$day days $hr : $min : $sec"
        else "$day day $hr : $min : $sec"
        tvFlashDealCountDownTime.text = formattedTimeStr
    }

    override fun onFinish() {
        tvFlashDealCountDownTime.text = "Done!"
    }
}.start()

传递一个未来日期并将其转换为毫秒。

- Shaon