【发布时间】：2020-08-23 19:43:00
【问题描述】：
当计时器到达 00:00 时，我在创建一种在前台发送通知的方法时遇到了一些麻烦。
我的意思是，我希望当计时器结束时，如果应用程序关闭，它会发送一个通知事件。
我已经找到了一种方法来显示通知并制作一个即使应用程序关闭也能工作的计时器。
但是当我把发送通知的功能放在计时器结束时，它只在应用程序打开时起作用。
这是我的 MainActivity.java
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
notificationManager = NotificationManagerCompat.from(this);
mTextViewCountDown = findViewById(R.id.timerTv);
mButtonStartPause = findViewById(R.id.btn_start_pause);
mButtonReset = findViewById(R.id.btn_reset);
mButtonStartPause.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (mTimerRunning) {
pauseTimer();
} else {
startTimer();
}
}
});
mButtonReset.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
resetTimer();
}
});
}
private void startTimer() {
mEndTime = System.currentTimeMillis() + mTimeLeftInMillis;
mCountDownTimer = new CountDownTimer(mTimeLeftInMillis, 1000) {
@Override
public void onTick(long millisUntilFinished) {
mTimeLeftInMillis = millisUntilFinished;
updateCountDownText();
}
@Override
public void onFinish() {
mTimeLeftInMillis=0;
updateCountDownText();
mTimerRunning = false;
updateButtons();
Notification notification = new NotificationCompat.Builder(getApplicationContext(), CHANNEL_1_ID)
.setSmallIcon(R.drawable.ic_money)
.setContentTitle("Test 1")
.setContentText("Important Message")
.setPriority(NotificationCompat.PRIORITY_HIGH)
.setCategory(NotificationCompat.CATEGORY_MESSAGE)
.build();
notificationManager.notify(1, notification);
}
}.start();
mTimerRunning = true;
updateButtons();
}
private void pauseTimer() {
mCountDownTimer.cancel();
mTimerRunning = false;
updateButtons();
}
private void resetTimer() {
mTimeLeftInMillis = START_TIME_IN_MILLIS;
updateCountDownText();
updateButtons();
}
private void updateCountDownText() {
int minutes = (int) (mTimeLeftInMillis / 1000) / 60;
int seconds = (int) (mTimeLeftInMillis / 1000) % 60;
String timeLeftFormatted = String.format(Locale.getDefault(), "%02d:%02d", minutes, seconds);
mTextViewCountDown.setText(timeLeftFormatted);
}
private void updateButtons() {
if (mTimerRunning) {
mButtonReset.setVisibility(View.INVISIBLE);
mButtonStartPause.setText("Pause");
} else {
mButtonStartPause.setText("Start");
if (mTimeLeftInMillis < 1000) {
mButtonStartPause.setVisibility(View.INVISIBLE);
} else {
mButtonStartPause.setVisibility(View.VISIBLE);
}
if (mTimeLeftInMillis < START_TIME_IN_MILLIS) {
mButtonReset.setVisibility(View.VISIBLE);
} else {
mButtonReset.setVisibility(View.INVISIBLE);
}
}
}
@Override
public void onStop() {
super.onStop();
SharedPreferences prefs = getSharedPreferences("pref", MODE_PRIVATE);
SharedPreferences.Editor editor = prefs.edit();
editor.putLong("millisLeft", mTimeLeftInMillis);
editor.putBoolean("timerRunning", mTimerRunning);
editor.putLong("endTime", mEndTime);
editor.apply();
if (mCountDownTimer != null) {
mCountDownTimer.cancel();
}
}
@Override
public void onStart() {
super.onStart();
SharedPreferences prefs = getSharedPreferences("pref", MODE_PRIVATE);
mTimeLeftInMillis = prefs.getLong("millisLeft", START_TIME_IN_MILLIS);
mTimerRunning = prefs.getBoolean("timerRunning", false);
updateCountDownText();
updateButtons();
if (mTimerRunning) {
mEndTime = prefs.getLong("endTime", 0);
mTimeLeftInMillis = mEndTime - System.currentTimeMillis();
if (mTimeLeftInMillis < 0) {
mTimeLeftInMillis = 0;
mTimerRunning = false;
updateCountDownText();
updateButtons();
} else {
startTimer();
}
}
}
}
应用 Java 类
public class App extends Application {
public static final String CHANNEL_1_ID = "channel1";
@Override
public void onCreate() {
super.onCreate();
createNotificationChannels();
}
private void createNotificationChannels() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
NotificationChannel channel1 = new NotificationChannel(
CHANNEL_1_ID,
"Channel 1",
NotificationManager.IMPORTANCE_HIGH
);
NotificationManager manager = getSystemService(NotificationManager.class);
manager.createNotificationChannel(channel1);
}
}
}
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.krisix.notificationtest">
<uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
<application
android:name=".App"
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<service android:name=".ExampleService"/>
</application>
</manifest>
感谢您的帮助！
祝你有美好的一天
Krisix
【问题讨论】：
-
在你的 onStop 方法的某个地方，你应该检查计时器是否完成，如果它完成了。并且应用程序停止，您可以启动通知，请查看此链接：stackoverflow.com/questions/39674850/…
标签： java android-studio notifications android-notifications countdowntimer