如何在 Android 操作栏创建带有通知数的图标?
本例演示了如何在 Android 操作栏创建带有通知数的图标
步骤 1 − 在 Android Studio 中创建新项目,转到文件 ⇒ 新项目并填写所有必需信息以创建新项目。
步骤 2 − 向 res/layout/activity_main.xml 添加以下代码。
<? 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" tools :context = ".MainActivity" > <Toolbar android :layout_width = "match_parent" android :layout_height = "?actionBarSize" android :background = "@color/colorPrimary" > <RelativeLayout android :layout_width = "match_parent" android :layout_height = "match_parent" android :layout_marginEnd = "16dp" > <TextView android :layout_width = "wrap_content" android :layout_height = "wrap_content" android :layout_centerVertical = "true" android :text = "Notify Me" android :textAppearance = "@style/Base.TextAppearance.AppCompat.Medium" android :textColor = "#FFF" android :textStyle = "bold" /> <RelativeLayout android :id= "@+id/notificationBadge" android :layout_width = "wrap_content" android :layout_height = "wrap_content" android :layout_alignParentEnd = "true" android :layout_centerVertical = "true" > <RelativeLayout android :id = "@+id/badgeLayout" android :layout_width = "wrap_content" android :layout_height = "wrap_content" android :paddingTop = "8dp" > <Button android :layout_width = "36dp" android :layout_height = "36dp" android :background = "@drawable/action_notification" /> </RelativeLayout> <TextView android :id = "@+id/tvBadgeNumber" android :layout_width = "wrap_content" android :layout_height = "wrap_content" android :layout_alignTop = "@+id/badgeLayout" android :layout_alignEnd = "@id/badgeLayout" android :background = "@drawable/item_count" android :text = "0" android :textColor = "#FFF" android :textSize = "16sp" android :textStyle = "bold" /> </RelativeLayout> </RelativeLayout> </Toolbar> <Button android :layout_width = "match_parent" android :layout_height = "wrap_content" android :layout_centerInParent = "true" android :layout_margin = "16dp" android :onClick = "createNotification" android :text = "create notification" /> </RelativeLayout>
步骤 3 − 向 src/MainActivity 添加以下代码。
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 android.widget.TextView ; public class MainActivity extends AppCompatActivity { public static final String NOTIFICATION_CHANNEL_ID = "10001" ; private final static String default_notification_channel_id = "default" ; static int notificationCount = 0 ; TextView tvBadgeNumber ; @Override protected void onCreate (Bundle savedInstanceState) { super .onCreate(savedInstanceState) ; setContentView(R.layout. activity_main ) ; tvBadgeNumber = findViewById(R.id. tvBadgeNumber ) ; } public void createNotification (View view) { 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(MainActivity. this, default_notification_channel_id ) ; mBuilder.setContentTitle( "My Notification" ) ; mBuilder.setContentIntent(pendingIntent) ; mBuilder.setContentText( "Notification Listener Service Example" ) ; mBuilder.setTicker( "Notification Listener Service Example" ) ; mBuilder.setSmallIcon(R.drawable. ic_launcher_foreground ) ; mBuilder.setAutoCancel( true ) ; 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()) ; notificationCount ++ ; tvBadgeNumber .setText(String. valueOf ( notificationCount )) ; } }
步骤 4 − 向 res/drawable/item_count.xml 添加以下代码
<? xml version = "1.0" encoding = "utf-8" ?> <shape xmlns: android = "http://schemas.android.com/apk/res/android" android :shape = "rectangle" > <corners android :radius = "8dp" /> <solid android :color = "#2196F3" /> <stroke android :width = "1dip" android :color = "#FFF" /> <padding android :bottom = "2dp" android :left = "2dp" android :right = "2dp" android :top = "2dp" /> </shape>
步骤 5 − 向 AndroidManifest.xml 添加以下代码
<? 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" /> <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 androidAdvertisements