通知的相关知识点

什么是通知？
通知一般是Service组件与用户交流一种常见方式。
通知将会显示在通知栏中。

如何发送一个简单通知？
1>获取 NotificationManager 通知管理器。
2>构建通知对象： Notification对象

 Builder builder =  new Builder();  Notification n = builder.setXX()                 .setXX()                 .setXX().build();

3>调用manager.notify方法发送通知。
具体代码如下，发送一个简单的 通知

private void sendNotification() {        //1   NotificationManager        NotificationManager manager =(NotificationManager)                 getSystemService(                Context.NOTIFICATION_SERVICE);        //2  构建Notification        Builder builder = new Builder(this);        builder.setContentInfo("ContentInfo")            .setContentText("ContentText")            .setContentTitle("ContentTitle")            .setLargeIcon(BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher))            .setSmallIcon(R.drawable.ic_launcher)            .setSubText("SubText")            .setTicker("状态栏中的滚动消息.....")            .setWhen(System.currentTimeMillis());        //通知常驻通知栏        builder.setOngoing(true);        Notification n = builder.build();        //1> n.flags = Notification.FLAG_NO_CLEAR;        //3.  manager.notify()        //NOTIFICATION_ID 自己定义的常量        manager.notify(NOTIFICATION_ID, n);    }

如何使通知常驻通知栏？
两种方式：
1>
Notification n;
n.flags = Notification.FLAG_NO_CLEAR
2>
builder.setOnGoing(true)

如何删除通知？
1>NotificationManager
2>manager.cancel(id)

private void clearNotification() {        //1. NotificationManager        NotificationManager manager = (NotificationManager)                 getSystemService(NOTIFICATION_SERVICE);        //2. manager.cancel()        manager.cancel(NOTIFICATION_ID);    }

如何修改通知内容？
修改通知的内容就是使用相同的ID再次发送一个
内容不同的通知。
这种方式不会重新出现滚动消息。

通过按钮点击来实现通知的修改，每点击一次，进度条加10

//修改通知中的内容privite number = 0;private void sendNotification2() {        //1. Manager        NotificationManager manager = (NotificationManager)                getSystemService(NOTIFICATION_SERVICE);        //2. Notification        Builder builder = new Builder(this);        builder.setTicker("开始下载....")            .setContentTitle("文件下载")            .setAutoCancel(true) //            .setContentText("当前进度："+number+"%")            //setSmallIcon()必要属性            .setSmallIcon(R.drawable.ic_launcher);        //给通知添加点击意图：        Intent intent = new Intent(this, MainActivity.class);        PendingIntent pi = PendingIntent.getActivity(this, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);        builder.setContentIntent(pi);        Notification n = builder.build();        //3. notify()        manager.cancel(NOTIFICATION_ID2);        manager.notify(NOTIFICATION_ID2, n);        number += 10;    }

如何更新通知内容的同时还要有滚动消息？
先删除该通知，再重新发一次。

如何点击通知后执行点击意图？
通知应用可以帮忙做的事情有3种：
startActivity()
startService()
sendBroadcast()

如何去做？

intent = new Intent(context, Activity.class);PendingIntent pi = PendingIntent.getActivity(,,,);builder.setContentIntent(PendingIntent)

如何编写带有进度条的通知？

builder.setProgress(
max, 进度条最大值
progress, 进度条当前值
indeterminate) 是否是不确定的

setProgress(0,0,false) 删除进度条
setProgress(0,0,true) 不确定的进度条

以一个模拟下载的例子来讲

private void sendNotification3() {        final NotificationManager manager = (NotificationManager)                getSystemService(NOTIFICATION_SERVICE);        //构建Notification对象        final Builder builder = new Builder(this);        builder.setTicker("音乐开始下载")            .setContentTitle("音乐下载")            .setSmallIcon(R.drawable.ic_launcher)            .setProgress(100, 0, true);        Notification n = builder.build();        //发送通知        manager.notify(NOTIFICATION_ID3, n);        //模拟下载  每隔1秒下载10%        new Thread(){            public void run() {                for(int i=1; i<=10; i++){                    try {                        Thread.sleep(1000);                    } catch (InterruptedException e) {                        e.printStackTrace();                    }                    //发送通知                    builder.setProgress(100, i*10, false);                    manager.notify(NOTIFICATION_ID3, builder.build());                }                //下载完成                builder.setProgress(0, 0, false)                    .setContentText("音乐已经下载完成"); //删掉进度条                manager.notify(NOTIFICATION_ID3, builder.build());            }        }.start();    }

如何自定义通知的UI界面？
RemoteViews views = new RemoteViews(layout);
//对views对象的控件进行操作
views.setxxxxxx()
builder.setContent(RemoteViews views);

如何实现：
1>编写一个xml布局。

新建notification_main.xml文件

<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">    <ImageView        android:id="@+id/ivPic"        android:layout_width="60dp"        android:layout_height="60dp"        android:layout_alignParentLeft="true"        android:layout_alignParentTop="true"        android:layout_marginRight="10dp"        android:src="@drawable/ic_launcher" />    <TextView        android:id="@+id/textView1"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignParentTop="true"        android:layout_toRightOf="@+id/ivPic"        android:layout_marginLeft="10dp"        android:text="歌名" />    <Button        android:id="@+id/button1"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignBottom="@+id/ivPic"        android:layout_below="@+id/textView1"        android:layout_toRightOf="@+id/ivPic"        android:text="&lt;" />    <Button        android:id="@+id/button2"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignBottom="@+id/button1"        android:layout_alignTop="@+id/button1"        android:layout_toRightOf="@+id/button1"        android:text="||" />    <Button        android:id="@+id/button3"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignBottom="@+id/button2"        android:layout_alignTop="@+id/button2"        android:layout_toRightOf="@+id/button2"        android:text=">" /></RelativeLayout>

效果如图

2>构建RemoteViews对象。
3>builder.setContent(views)

如何当点击RemoteViews中的按钮时，执行点击意图？
RemoteViews views;
views.setOnClickPendingIntent();

private void sendNotification4() {        NotificationManager manager = (NotificationManager)                getSystemService(NOTIFICATION_SERVICE);        //构建Notification对象        Builder builder = new Builder(this);        builder.setSmallIcon(R.drawable.ic_launcher)            .setTicker("滚动消息");        //自定义RemoteViews对象        RemoteViews views = new RemoteViews(this.getPackageName(), R.layout.notification_main);        //给views中的按钮添加点击意图，点击第一个按钮，回到主页面        Intent i1 = new Intent(this, MainActivity.class);        PendingIntent pi1 = PendingIntent.getActivity(this, 0, i1, PendingIntent.FLAG_UPDATE_CURRENT);        views.setOnClickPendingIntent(R.id.button1, pi1);        //点击第二个按钮发送广播        Intent i2 = new Intent("ACTION_CLICK_BUTTON2");        PendingIntent pi2 = PendingIntent.getBroadcast(this, 0, i2, PendingIntent.FLAG_UPDATE_CURRENT);        views.setOnClickPendingIntent(R.id.button2, pi2);        builder.setContent(views);        Notification n = builder.build();        //发送通知        manager.notify(NOTIFICATION_ID4, n);    }

在OnCreate()方法中，动态注册广播

//注册广播接收器        receiver = new MyReceiver();        IntentFilter filter = new IntentFilter();        filter.addAction("ACTION_CLICK_BUTTON2");        registerReceiver(receiver, filter);//取消注册    protected void onDestroy() {        this.unregisterReceiver(receiver);        super.onDestroy();    }

main_activity.xml 中代码如下

<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" >    <Button        android:id="@+id/button1"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignParentLeft="true"        android:layout_alignParentRight="true"        android:layout_alignParentTop="true"        android:onClick="doClick"        android:text="点我发通知" />    <Button        android:id="@+id/button2"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignParentLeft="true"        android:layout_alignParentRight="true"        android:layout_below="@+id/button1"        android:onClick="doClick"        android:text="删除通知" />    <Button        android:id="@+id/button3"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignParentLeft="true"        android:layout_alignParentRight="true"        android:layout_below="@+id/button2"        android:onClick="doClick"        android:text="测试修改通知的内容" />    <Button        android:id="@+id/button4"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignParentLeft="true"        android:layout_alignParentRight="true"        android:layout_below="@+id/button3"        android:onClick="doClick"        android:text="带有进度条的通知" />    <Button        android:id="@+id/button5"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignParentLeft="true"        android:layout_alignParentRight="true"        android:layout_below="@+id/button4"        android:onClick="doClick"        android:text="发送自定义通知" /></RelativeLayout>

为各个按钮设置点击事件

public void doClick(View view){        switch (view.getId()) {        case R.id.button5: // 自定义通知            sendNotification4();            break;        case R.id.button4: // 带有进度条的通知            sendNotification3();            break;        case R.id.button3: //修改通知的内容            sendNotification2();            break;        case R.id.button2: //清除通知            clearNotification();            break;        case R.id.button1: //发送通知            sendNotification();            break;        }    }

源码如下

• https://github.com/xinruzhishui11/android_day11_notification