如何在Android手机重启后保持状态栏通知持久显示？

本例演示了如何在Android手机重启后保持状态栏通知持久显示

步骤 1 − 在Android Studio中创建一个新项目，转到文件 ⇒ 新建项目，并填写所有必需的详细信息以创建新项目。

步骤 2 − 将以下代码添加到res/layout/activity_main.xml。

<? xml version = "1.0" encoding = "utf-8" ?>
<RelativeLayout xmlns: android = "http://schemas.android.com/apk/res/android"
   xmlns: tools = "http://schemas.android.com/tools"
   android :layout_width = "match_parent"
   android :layout_height = "match_parent"
   android :padding = "16dp"
   tools :context = ".MainActivity" / >

步骤 3 − 将以下代码添加到src/MainActivity.java。

package app.tutorialspoint.com.notifyme ;
import android.os.Bundle ;
import android.support.v7.app.AppCompatActivity ;
public class MainActivity extends AppCompatActivity {
   @Override
   protected void onCreate (Bundle savedInstanceState) {
      super .onCreate(savedInstanceState) ;
      setContentView(R.layout. activity_main ) ;
   }
}

步骤 4 − 将以下代码添加到src/USBStateReceiver.java。

package app.tutorialspoint.com.notifyme ;
import android.annotation. SuppressLint ;
import android.app.Notification ;
import android.app.NotificationChannel ;
import android.app.NotificationManager ;
import android.content.BroadcastReceiver ;
import android.content.Context ;
import android.content.Intent ;
import android.support.v4.app.NotificationCompat ;
import android.util.Log ;
public class USBStateReceiver extends BroadcastReceiver {
   public static final String NOTIFICATION_CHANNEL_ID = "10001" ;
   private final static String default_notification_channel_id = "default" ;
   boolean connected = true;
   @SuppressLint ( "UnsafeProtectedBroadcastReceiver" )
   @Override
   public void onReceive (Context context , Intent intent) {
      NotificationCompat.Builder builder = new NotificationCompat.Builder(context , default_notification_channel_id ) ;
      builder.setContentTitle( "USB - Notification" ) ;
      String action = intent.getAction() ;
      Log. e ( "USB" , action) ;
      assert action != null;
      builder.setContentText( "Connected" ) ;
      builder.setSmallIcon(R.drawable. ic_launcher_foreground ) ;
      builder.setAutoCancel( true ) ;
      builder.setChannelId( NOTIFICATION_CHANNEL_ID ) ;
      Notification notification = builder.build() ;
      NotificationManager notificationManager = (NotificationManager) context.getSystemService(Context. NOTIFICATION_SERVICE ) ;
      if (android.os.Build.VERSION. SDK_INT >= android.os.Build.VERSION_CODES. O ) {
         int importance = NotificationManager. IMPORTANCE_HIGH ;
         NotificationChannel notificationChannel = new NotificationChannel( NOTIFICATION_CHANNEL_ID , "NOTIFICATION_CHANNEL_NAME" , importance) ;
         assert notificationManager != null;
         notificationManager.createNotificationChannel(notificationChannel) ;
      }
      assert notificationManager != null;
      if ( connected ) {
         notificationManager.notify( 1 , notification) ;
         connected = false;
      } else {
         notificationManager.cancel( 1 ) ;
         connected = true;
   }
}

步骤 5 − 将以下代码添加到AndroidManifest.xml

<? xml version= "1.0" encoding= "utf-8" ?>
<manifest xmlns: android = "http://schemas.android.com/apk/res/android"
   package = "app.tutorialspoint.com.notifyme" >
   <uses-permission android :name = "android.permission.VIBRATE" />
   <uses-permission android :name = "android.permission.RECEIVE_BOOT_COMPLETED" />
   <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>
      <receiver android :name = ".USBStateReceiver" >
         <intent-filter>
            <action android :name = "android.intent.action.BOOT_COMPLETED" />
         </intent-filter>
      </receiver>
   <application>
</manifest>

让我们尝试运行您的应用程序。我假设您已将实际的Android移动设备连接到计算机。要从Android Studio运行应用程序，请打开项目中的一个活动文件，然后单击工具栏中的运行 图标。选择您的移动设备作为选项，然后检查您的移动设备，它将显示您的默认屏幕−

点击 这里 下载项目代码

更新于：2020年7月3日

429 次浏览

启动您的职业生涯

完成课程获得认证

开始学习
广告