Android 計時器，定時功能

計時器工具類

import android.annotation.SuppressLint;
import android.os.Handler;
import android.os.Message;

import androidx.annotation.NonNull;

import java.util.Timer;
import java.util.TimerTask;

/**
 * 用于計時，在主執行緒中使用此方法
 */
public class ChjTimer {

    private int time;//設定倒計時 X 秒
    private int interval = 1000;//設定間隔時間
    private ChjTimerInter chjTimerInter; //回呼
    private Timer timer; // 定時器
    private static final int WHAT_REFREH = 0;//重繪

    /**
     * 創建物件則開始計時
     *
     * @param chjTimerInter 介面回呼
     */
    public ChjTimer(ChjTimerInter chjTimerInter) {
        this.chjTimerInter = chjTimerInter;
    }

    /**
     * 創建物件開始計時
     * @param interval      間隔時間通知(使用第一個方法，默認1秒鐘重繪一次)
     * @param chjTimerInter 介面回呼
     */
    public ChjTimer(int interval, ChjTimerInter chjTimerInter) {
        this.chjTimerInter = chjTimerInter;
        this.interval = interval;
    }

    /**
     * 開始計時
     */
    public void start(int time) {
        this.time = time;
        if (timer == null){
            timer = new Timer();
        } else {
            stop();
            return;
        }
        timer.schedule(new TimerTask() {
            @Override
            public void run() {
                timesss.sendMessage(new Message());
            }
        }, interval);
    }

    /**
     * 終止計時
     */
    public void stop() {
        if (timer != null) {
            timer.cancel();
            timer = null;
        }
        if (timesss != null) timesss.removeMessages(WHAT_REFREH);
        if (chjTimerInter != null)chjTimerInter.stop(time);
    }

    @SuppressLint("HandlerLeak")
    private Handler timesss = new Handler() {
        @Override
        public void handleMessage(@NonNull Message msg) {
            super.handleMessage(msg);
            if (msg.what != WHAT_REFREH) return;
            time -= 1;
            if (chjTimerInter != null) chjTimerInter.second(time);
            if (time == 0) {
                if (timer == null) return;
                timer.cancel();
                timer = null;
                if (chjTimerInter != null) chjTimerInter.expire();
            } else if (time > 0) {
                timer.schedule(new TimerTask() {
                    @Override
                    public void run() {
                        timesss.sendMessage(new Message());
                    }
                }, interval);
            }
        }
    };

    /**
     * 介面
     */
    public interface ChjTimerInter {

        /**
         * 間隔時間內回呼
         */
        void second(int time);

        /**
         * 完成回呼
         */
        void expire();

        /**
         * 終止計時
         */
        void stop(int time);

    }

}

使用演示

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

public class MainActivity extends Activity implements View.OnClickListener, ChjTimer.ChjTimerInter {

    private TextView tiems,timnew;
    private ChjTimer chjTimer;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tiems = findViewById(R.id.time);
        timnew = findViewById(R.id.timnew);
        findViewById(R.id.but).setOnClickListener(this);
        findViewById(R.id.buts).setOnClickListener(this);

        chjTimer = new ChjTimer(this);
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()){
            case R.id.but:
                tiems.setText("10");
                timnew.setText("正在計時");
                chjTimer.start(10);
                break;
            case R.id.buts:
                chjTimer.stop();
                break;
        }
    }

    @Override
    public void second(int time) {
        tiems.setText(time + "");
    }

    @Override
    public void expire() {
        timnew.setText("計時完成");
    }

    @Override
    public void stop(int time) {
        timnew.setText("計時終止" + time);
    }
}

頁面 布局

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:orientation="vertical"
    android:layout_gravity="center"
    android:gravity="center"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/timnew"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="計時完成"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/time"
        android:text="0"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />


    <Button
        android:id="@+id/but"
        android:text="開始"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <Button
        android:id="@+id/buts"
        android:text="終止"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</LinearLayout>

演示效果