一、基础

App定时提醒（AlarmManager实现，适配不同版本）

二、使用

//build.gradle
apply plugin: 'com.android.application'

android {
    compileSdkVersion 29

    defaultConfig {
        applicationId "com.tomorrow.second"
        minSdkVersion 15
        targetSdkVersion 29
        versionCode 1
        versionName "1.0"
        
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])

    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
}

//AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.tomorrow.second">

    <application
        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=".TestService">
            <intent-filter>
                <action android:name="com.tomorrow.intent.service" />
            </intent-filter>
        </service>
    </application>

</manifest>

//MainActivity
public class MainActivity extends Activity {
    private static final String TAG = "MainActivity";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Log.d(TAG, "zwm, onCreate");

        AlarmManager alarmManager = (AlarmManager)getSystemService(Context.ALARM_SERVICE);
        Intent intent = new Intent("com.tomorrow.intent.service");
        PendingIntent sender = PendingIntent.getService(this, 1, intent, PendingIntent.FLAG_CANCEL_CURRENT);
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            alarmManager.setExactAndAllowWhileIdle(AlarmManager.ELAPSED_REALTIME_WAKEUP, SystemClock.elapsedRealtime() + 10000, sender);
        } else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
            alarmManager.setExact(AlarmManager.ELAPSED_REALTIME_WAKEUP, SystemClock.elapsedRealtime() + 10000, sender);
        } else {
            alarmManager.setRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP, SystemClock.elapsedRealtime(), 10000, sender);
        }
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        Log.d(TAG, "zwm, onDestroy");
        AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
        Intent intent = new Intent("com.tomorrow.intent.service");
        PendingIntent sender = PendingIntent.getService(this, 1, intent, PendingIntent.FLAG_CANCEL_CURRENT);
        alarmManager.cancel(sender);
    }
}

//TestService
public class TestService extends Service {
    private static final String TAG = "TestService";

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

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.d(TAG, "zwm, onStartCommand");
        AlarmManager alarmManager = (AlarmManager)getSystemService(Context.ALARM_SERVICE);
        Intent newIntent = new Intent("com.tomorrow.intent.service");
        PendingIntent sender = PendingIntent.getService(this, 1, newIntent, PendingIntent.FLAG_CANCEL_CURRENT);
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            alarmManager.setExactAndAllowWhileIdle(AlarmManager.ELAPSED_REALTIME_WAKEUP, SystemClock.elapsedRealtime() + 10000, sender);
        } else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
            alarmManager.setExact(AlarmManager.ELAPSED_REALTIME_WAKEUP, SystemClock.elapsedRealtime() + 10000, sender);
        }
        return super.onStartCommand(intent, flags, startId);
    }
}

//输出log
2019-11-18 14:33:26.318 10012-10012/com.tomorrow.second D/MainActivity: zwm, onCreate
2019-11-18 14:33:26.791 10012-10012/com.tomorrow.second D/TestService: zwm, onStartCommand
2019-11-18 14:33:36.859 10012-10012/com.tomorrow.second D/TestService: zwm, onStartCommand
2019-11-18 14:33:46.872 10012-10012/com.tomorrow.second D/TestService: zwm, onStartCommand
2019-11-18 14:33:49.920 10012-10012/com.tomorrow.second D/MainActivity: zwm, onDestroy