Question

我是Android编程的新手，我有一个问题。

当我触摸屏幕时，我有一个倒数从60倒数到零。我现在想要即使在调用onDestroy时，这个倒计时将在Activity生命周期中存活下来。所以我需要一个服务。

Wenn倒计时结束后会发送通知。但是，如果用户想要在服务倒计时结束之前再次打开应用程序，则不应发出任何通知，并且必须停止服务。

实施这些功能的最佳做法是什么？这是怎么回事？

非常感谢您的回答！

我的方法是我有一个带倒计时方法和服务的课程

// Countdownclass TimerClass.java

public class TimerClass {
private static final String TAG = "MyLog";
private static final long TIMERINTERVAL = 1000;
//Eigenschaften --------------------------------------------------------------------
private boolean isActiv = false;
private Paint paint;
private long timerTime;
private double actualTime;
private int x;
private int y;
private CountDownTimer countDownTimer;
private String timeString;

//Konstruktor --------------------------------------------------------------------
public TimerClass(int x, int y) {
    this.x = x;
    this.y = y;
    paint = new Paint();
    paint.setStyle(Paint.Style.FILL);
    paint.setColor(Color.YELLOW);
    paint.setAntiAlias(true);
    paint.setTextAlign(Align.RIGHT);
    paint.setTextSize(70);
}

public TimerClass() {

}

//Methoden --------------------------------------------------------------------
public void draw(Canvas canvas) {
    if(isActiv) {
        canvas.drawText(timeString, x, y, paint);
    }
}

public void createTimer(long timerTime) {
    this.timerTime = timerTime;
    countDownTimer = new CountDownTimer(timerTime, TIMERINTERVAL) {

        @Override
        public void onTick(long millisUntilFinished) {

            actualTime = (double) millisUntilFinished / TIMERINTERVAL;
            NumberFormat nf = new DecimalFormat("##.#");
            nf.format(actualTime);

            if(actualTime < 10) {
                new DecimalFormat();
                timeString = "0:0" + nf.format(actualTime  - 1);
            } else {
                timeString = "0:" + nf.format(actualTime  - 1);
            }
        }

        @Override
        public void onFinish() {
            isActiv = false;
        }
    };

}

public void timerStart() {
    countDownTimer.start();
    isActiv = true;
}

public void timerStop() {
    if(isActiv) {
        countDownTimer.cancel();
    }
    isActiv = false;

}

public boolean isActiv() {
    return isActiv;
}

public void setActiv(boolean isActiv) {
    this.isActiv = isActiv;
}

public double getActualTime() {
    return actualTime;
}

public void setActualTime(double actualTime) {
    this.actualTime = actualTime;
}

我的服务：

public class TimerService extends Service {

//class with the countdowntimer
private TimerClass timerClass;
private long startTime;

@Override
public IBinder onBind(Intent intent) {
    return null;
}

@Override
public void onCreate() {
    super.onCreate();

    timerClass = new TimerClass();
    startTime = (long) timerClass.getActualTime();
    timerClass.createTimer(startTime);
}

@Override
public void onDestroy() {
    timerClass.timerStop();
    super.onDestroy();
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    timerClass.timerStart();        
    if(timerClass.getActualTime() <= 0) {
        // send the notification
    }
    return super.onStartCommand(intent, flags, startId);
}

我想在mainActivies onPause方法中启动服务，并在调用onResume时停止它。但是我已经尝试了很多次但都失败了......所以我的活动中没有代码供我服务。

（抱歉我的英语不好:(）

最佳实践：如何在服务中绘制倒计时

0 个答案: