Android中使用CountDownTimer封装CountDownUtil，制作一个简易定时器

编写不易，如有转载，请声明出处：http://blog.youkuaiyun.com/zxc514257857/article/details/75022049

Demo展示图片

布局代码

// (layout)activity_main.xml
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.test.countdownutil.MainActivity">

    <TextView
        android:id="@+id/textview"
        android:textSize="26sp"
        android:textColor="#f00"
        android:textStyle="bold"
        android:layout_centerInParent="true"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

    <LinearLayout
        android:layout_alignParentBottom="true"
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <Button
            android:layout_gravity="bottom"
            android:text="start"
            android:onClick="start"
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="wrap_content"/>

        <Button
            android:id="@+id/pause"
            android:layout_gravity="bottom"
            android:text="||"
            android:onClick="pause"
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="wrap_content"/>

        <Button
            android:layout_gravity="bottom"
            android:text="stop"
            android:onClick="stop"
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="wrap_content"/>

    </LinearLayout>
</RelativeLayout>

逻辑代码

// CountDownUtil
import android.os.CountDownTimer;

public class CountDownUtil {

    /**
     * 倒计时结束的回调接口
     */
    public interface FinishDelegate {
        void onFinish();
    }

    /**
     * 定期回调的接口
     */
    public interface TickDelegate {
        void onTick(long pMillisUntilFinished);
    }

    private final static long ONE_SECOND = 1000;

    /**
     * 总倒计时时间
     */
    private long mMillisInFuture = 0;

    /**
     * 定期回调的时间 必须大于0 否则会出现ANR
     */
    private long mCountDownInterval;

    /**
     * 倒计时结束的回调
     */
    private FinishDelegate mFinishDelegate;

    /**
     * 定期回调
     */
    private TickDelegate mTickDelegate;
    private MyCountDownTimer mCountDownTimer;

    /**
     * 获取 CountDownTimerUtils
     * @return CountDownTimerUtils
     */
    public static CountDownUtil getCountDownTimer() {
        return new CountDownUtil();
    }

    /**
     * 设置定期回调的时间 调用{@link #setTickDelegate(TickDelegate)}
     * @param pCountDownInterval 定期回调的时间 必须大于0
     * @return CountDownTimerUtils
     */
    public CountDownUtil setCountDownInterval(long pCountDownInterval) {
        this.mCountDownInterval=pCountDownInterval;
        return this;
    }

    /**
     * 设置倒计时结束的回调
     * @param pFinishDelegate 倒计时结束的回调接口
     * @return CountDownTimerUtils
     */
    public CountDownUtil setFinishDelegate(FinishDelegate pFinishDelegate) {
        this.mFinishDelegate=pFinishDelegate;
        return this;
    }

    /**
     * 设置总倒计时时间
     * @param pMillisInFuture 总倒计时时间
     * @return CountDownTimerUtils
     */
    public CountDownUtil setMillisInFuture(long pMillisInFuture) {
        this.mMillisInFuture=pMillisInFuture;
        return this;
    }

    /**
     * 设置定期回调
     * @param pTickDelegate 定期回调接口
     * @return CountDownTimerUtils
     */
    public CountDownUtil setTickDelegate(TickDelegate pTickDelegate) {
        this.mTickDelegate=pTickDelegate;
        return this;
    }

    public void create() {
        if (mCountDownTimer != null) {
            mCountDownTimer.cancel();
            mCountDownTimer = null;
        }
        if (mCountDownInterval <= 0) {
            mCountDownInterval = mMillisInFuture + ONE_SECOND;
        }
        mCountDownTimer = new MyCountDownTimer(mMillisInFuture, mCountDownInterval);
        mCountDownTimer.setTickDelegate(mTickDelegate);
        mCountDownTimer.setFinishDelegate(mFinishDelegate);
    }

    /**
     * 开始倒计时
     */
    public void start() {
        if (mCountDownTimer == null) {
            create();
        }
        mCountDownTimer.start();
    }

    /**
     * 取消倒计时
     */
    public void cancel() {
        if (mCountDownTimer != null) {
            mCountDownTimer.cancel();
        }
    }

    private static class MyCountDownTimer extends CountDownTimer {
        private FinishDelegate mFinishDelegate;
        private TickDelegate mTickDelegate;
        public MyCountDownTimer(long millisInFuture, long countDownInterval) {
            super(millisInFuture, countDownInterval);
        }
        @Override
        public void onTick(long millisUntilFinished) {
            if (mTickDelegate != null) {
                mTickDelegate.onTick(millisUntilFinished);
            }
        }
        @Override
        public void onFinish() {
            if (mFinishDelegate != null) {
                mFinishDelegate.onFinish();
            }
        }
        void setFinishDelegate(FinishDelegate pFinishDelegate) {
            this.mFinishDelegate=pFinishDelegate;
        }
        void setTickDelegate(TickDelegate pTickDelegate) {
            this.mTickDelegate=pTickDelegate;
        }
    }
}
----------------------------------------------------------------------------------------
// MainActivity

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.TimeZone;

public class MainActivity extends AppCompatActivity {

    private TextView mTextView;
    private long countDownInterval = 0;
    private SimpleDateFormat mFormatter;
    private CountDownUtil mCountDownUtil;
    private boolean pauseOn = true;
    private Button mPause;
    private String mStartHms;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
        initData();
    }

    public void initView(){
        mTextView = (TextView) findViewById(R.id.textview);
        // 格式化时间 将毫秒格式化为时分秒
        mFormatter = new SimpleDateFormat("HH:mm:ss");
        // 格式化时间 从0时开始而不是从8时开始
        mFormatter.setTimeZone(TimeZone.getTimeZone("GMT+00:00"));
        mPause = (Button) findViewById(R.id.pause);
    }

    public void initData(){
        // 初始化倒计时界面
        initCountDown();
    }

    /**
     * 开始倒计时,传入总时间和每一秒要倒计时的时间
     */
    private void countDown(final long millisInFuture , long countDownInterval) {
        mCountDownUtil = CountDownUtil.getCountDownTimer()
                // 倒计时总时间
                .setMillisInFuture(millisInFuture)
                // 每隔多久回调一次onTick
                .setCountDownInterval(countDownInterval)
                // 每回调一次onTick执行
                .setTickDelegate(new CountDownUtil.TickDelegate() {
                    @Override
                    public void onTick(long pMillisUntilFinished) {
                        String mHms = mFormatter.format(pMillisUntilFinished);
                        mTextView.setText(mHms);
                    }
                })
                // 结束倒计时执行
                .setFinishDelegate(new CountDownUtil.FinishDelegate() {
                    @Override
                    public void onFinish() {
                        Toast.makeText(MainActivity.this, millisInFuture + "倒计时完成!", Toast.LENGTH_SHORT).show();
                    }
                });
    }

    /**
     * 初始化倒计时界面
     */
    public void initCountDown(){
        // 倒计时总时间为3h
        long millisInFuture = 1000 * 60 * 60 * 3;
        // 每隔1s回调一次onTick
        countDownInterval = 1000;
        // 格式化倒计时开始时间
        mStartHms = mFormatter.format(millisInFuture);
        // 将时间显示到界面
        mTextView.setText(mStartHms);
        // 开始倒计时,传入总时间和每一秒要倒计时的时间
        countDown(millisInFuture , countDownInterval);
    }

    /**
     * 点击开始按钮
     */
    public void start(View view){
        // 点击开始按钮  如果不是倒计时开始和结束时不响应此按钮
        if(mTextView.getText().equals("00:00:00") || mTextView.getText().equals(mStartHms)){
            // 初始化倒计时界面
            initCountDown();
            // 开始倒计时
            mCountDownUtil.start();
            Toast.makeText(this, "开始倒计时!", Toast.LENGTH_SHORT).show();
        }
    }

    /**
     * 点击暂停按钮
     */
    public void pause(View view) throws ParseException {
        // 结束倒计时 不清零
        mCountDownUtil.cancel();
        // 暂停倒计时
        if(pauseOn){
            mPause.setText("▲");
            pauseOn = false;
            Toast.makeText(this, "暂停倒计时!", Toast.LENGTH_SHORT).show();
            // 取消暂停
        }else{
            mPause.setText("||");
            pauseOn = true;
            // 获取目前的倒计时时间
            String now = (String) mTextView.getText();
            long time = mFormatter.parse(now).getTime();
            // 如果倒计时时间大于0
            if(time > 0){
                // 继续倒计时
                countDown(time , countDownInterval);
                mCountDownUtil.start();
                Toast.makeText(this, "取消暂停倒计时!", Toast.LENGTH_SHORT).show();
                // 如果倒计时时间小于或等于0
            }else{
                // 倒计时时间异常
                Toast.makeText(this, "倒计时时间异常!", Toast.LENGTH_SHORT).show();
            }
        }
    }

    /**
     * 点击停止按钮
     */
    public void stop(View view){
        // 结束倒计时并归零
        mTextView.setText("00:00:00");
        mCountDownUtil.cancel();
        Toast.makeText(this, "结束倒计时!", Toast.LENGTH_SHORT).show();
    }
}

Demo下载请移步：http://download.youkuaiyun.com/download/zxc514257857/9896528


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