如何在 Android 应用启动器图标中显示通知数量?
androidapps/applicationsmobile development更新于 2026/2/15 17:52:17
此示例演示了如何在 Android 应用启动器图标中显示通知数量。
步骤 1 − 在 Android Studio 中创建一个新项目，前往"文件"->"新建项目"，并填写所有必填信息以创建新项目。
步骤 2 − 将以下代码添加到 res/layout/activity_main.xml。
<? xml version = "1.0" encoding = "utf-8" ?7gt; <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" > <Button android:onClick = "createNotification" android:text = "create notification" android:layout_centerInParent = "true" android:layout_width = "match_parent" android:layout_height = "wrap_content" /> </RelativeLayout>
步骤 3 − 将以下代码添加到 src/MainActivity。
package app.tutorialspoint.com.notifyme ;
import android.app.NotificationChannel ;
import android.app.NotificationManager ;
import android.app.PendingIntent ;
import android.content.Intent ;
import android.os.Bundle ;
import android.support.v4.app.NotificationCompat ;
import android.support.v7.app.AppCompatActivity ;
import android.view.View ;
import static android.app.Notification. BADGE_ICON_SMALL ;
public class MainActivity extends AppCompatActivity {
static int count = 0 ;
public static final String NOTIFICATION_CHANNEL_ID = "10001" ;
private final static String default_notification_channel_id = "default" ;
@Override
protected void onResume () {
super .onResume() ;
count = 0 ;
}
@Override
protected void onCreate (Bundle savedInstanceState) {
super .onCreate(savedInstanceState) ;
setContentView(R.layout. activity_main ) ;
}
public void createNotification (View view) {
count ++ ;
Intent notificationIntent = new Intent(getApplicationContext() , MainActivity. class ) ;
notificationIntent.putExtra( "fromNotification" , true ) ;
notificationIntent.setFlags(Intent. FLAG_ACTIVITY_CLEAR_TOP | Intent. FLAG_ACTIVITY_SINGLE_TOP ) ;
PendingIntent pendingIntent = PendingIntent. getActivity ( this, 0 , notificationIntent , 0 ) ;
NotificationManager mNotificationManager = (NotificationManager) getSystemService( NOTIFICATION_SERVICE ) ;
NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(getApplicationContext() , default_notification_channel_id ) ;
mBuilder.setContentTitle( "My Notification" ) ;
mBuilder.setContentIntent(pendingIntent) ;
mBuilder.setContentText( "Notification Listener Service Example" ) ;
mBuilder.setSmallIcon(R.drawable. ic_launcher_foreground ) ;
mBuilder.setAutoCancel( true ) ;
mBuilder.setBadgeIconType( BADGE_ICON_SMALL ) ;
mBuilder.setNumber( count ) ;
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) ;
mBuilder.setChannelId( NOTIFICATION_CHANNEL_ID ) ;
assert mNotificationManager != null;
mNotificationManager.createNotificationChannel(notificationChannel) ;
}
assert mNotificationManager != null;
mNotificationManager.notify(( int ) System. currentTimeMillis () , mBuilder.build()) ;
}
}
步骤 4 − 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 :allowBacku p= "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> </application> </manifest>
让我们尝试运行您的应用程序。假设您已将实际的 Android 移动设备连接到电脑。要从 Android Studio 运行该应用程序，请打开项目的某个活动文件，然后点击工具栏上的"运行"图标 
。选择您的移动设备作为选项，然后勾选将显示默认屏幕的移动设备
点击此处下载项目代码
