某学姐

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Android学习笔记——Notification和RemoteView

2018-09-10 | Comments

这部分主要涉及的知识点:
(1)RemoteView
(2)PendingIntent
(3)Notification

任玉刚的《Android开发艺术探索》里有第5章“理解RemoteViews”讲的比较详细。

RemoteView

应用场景:主要是用在通知栏Notification、桌面小部件AppWidgetProvider场景

内部机制:跨进程显示并更新View

支持的View的类型有限:
Layout – FrameLayout, LinearLayout, RelativeLayout, GridLayout
View – AnalogClock, Button, Chronometer, ImageButton, ImageView, ProgressBar, TextView, ViewFlipper, ListView, GridView, StackView, AdapterViewFlipper, ViewStub

public class RemoteViews implements Parcelable    
private abstract static class Action implements Parcelable    

RemoteViews维护了一个List,使用了反射机制,每一个set方法实际上就是一个对View的操作的Action。

PendingIntent

PendingIntent.getActivity(Context context, int requestCode, Intent intent, int flags)

PendingIntent.getService(Context context, int requestCode, Intent intent, int flags)

PendingIntent.getBroadcast(Context context, int requestCode, Intent intent, int flags)

flags参数:

FLAG_ONE_SHOT
FLAG_NO_CREATE
FLAG_CANCEL_CURRENT
FLAG_UPDATE_CURRENT

Notification

示例代码:

RemoteViews notificationView = new RemoteViews(context.getPackageName(), R.layout.xxx);
notificationView.setTextViewText(R.id.title, title);
notificationView.setTextViewText(R.id.content, content);
notificationView.setImageViewResource(R.id.icon, icon);
  
PendingIntent contentIntent = PendingIntent.getActivity(context, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);

Notification notification = new NotificationCompat.Builder(context)
  .setCustomContentView(notificationView)
  .setContentIntent(contentIntent)
  ....
  .build();

NotificationManager nm = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
nm.notify(id, notification);

target 26开始,通知栏部分涉及到NotificationChannel概念,即Notification的显示需要先创建NotificationChannel,通过NotificationChannel来控制Notification的显示逻辑。

官方文档:
https://developer.android.com/reference/android/app/PendingIntent
https://developer.android.com/reference/android/widget/RemoteViews
https://developer.android.com/reference/android/app/Notification
https://developer.android.com/reference/android/app/NotificationChannel

本文原文发自 某学姐, 转载请保留出处, 谢谢.

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