通知的相关知识点

Posted 2022-11-22 xinruzhishui_11

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