【Android】手机多媒体的使用—通知、摄像头、播放音乐视频

使用通知

在Android 8.0(API26)后对通知更改了一些内容，以前是通过Notification,Builder(Context context).se.来设置通知的震动、灯光、音效的设置，新内容加了NotificationChannel(通知渠道)，通过NotificatonChannel来进行震动、灯光、音效的设置，且通知必须添加通知渠道，同样需进行版本判断，否则通知不会被发送。

1. 首先创建NotificationManager对象
2. .创建Notificationchannel对象，指定id,name,importance(根据这个播放对应的效果)，也可以设置相应的震动、音效、如果没设置按默认的importance,调用NotificationManager的createNotificationChannel(NotificationChannel channel)方法
3. 通过Notificationcompat.Builder(Context.Notification)对象指定channel并设置通知的各项信息，调用buid()方法创建Notifcation对象
4. 调用NotificationManager的notify(id,Notification)方法发送通知

基础用法

新建NotificationTest项目

修改activity中的代码：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <Button
        android:id="@+id/send_notice"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Send notice"/>

</LinearLayout>

简单加了一个Send notice按钮

下来修改MainActivity中的代码：

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
   

    @Override
    protected void onCreate(Bundle savedInstanceState) {
   
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button sendNotice = (Button) findViewById(R.id.send_notice);
        sendNotice.setOnClickListener(this);
    }
    

    @SuppressLint("NotificationPermission")
    @Override
    public void onClick(View v) {
   
        if (v.getId() == R.id.send_notice) {
   
            NotificationManager manager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
            Notification notification = new NotificationCompat.Builder(this)
                    .setContentTitle("This is content title")
                    .setContentText("This is content text")
                    .setWhen(System.currentTimeMillis())
                    .setSmallIcon(R.mipmap.ic_launcher)
                    .setLargeIcon(BitmapFactory.decodeResource(getResources(), R.mipmap.ic_launcher))
                    .build();
            manager.notify(1, notification);
        }
    }
}

上面是Android8.0版本前才能使用

在Android13，版本通知的使用发生了新的变化：

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
   

    private static final String CHANNEL_ID = "notification_channel";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
   
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button sendNotice = findViewById(R.id.send_notice);
        sendNotice.setOnClickListener(this);

        createNotificationChannel();
    }

    // 创建通知渠道
    private void createNotificationChannel() {
   
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
   
            CharSequence name = "Notification Channel";
            String description = "Channel for notifications";
            int importance = NotificationManager.IMPORTANCE_DEFAULT;
            NotificationChannel channel = new NotificationChannel(CHANNEL_ID, name, importance);
            channel.setDescription(description);
            NotificationManager notificationManager = getSystemService(NotificationManager.class);
            notificationManager.createNotificationChannel(channel);
        }
    }

    @SuppressLint("NotificationPermission")
    @Override
    public void onClick(View v) {
   
        // 申请通知权限
        if (ContextCompat.checkSelfPermission(MainActivity.this,
                android.Manifest.permission.POST_NOTIFICATIONS) != PackageManager.PERMISSION_GRANTED) {
   
            ActivityCompat.requestPermissions(MainActivity.this, new String[]{
   android.Manifest.permission.POST_NOTIFICATIONS}, 1);
        }

        if (v.getId() == R.id.send_notice) {
   
            NotificationCompat.Builder builder = new NotificationCompat.Builder(this, CHANNEL_ID)
                    .setSmallIcon(R.mipmap.ic_launcher) // 设置小图标
                    .setContentTitle("This is content title") // 设置通知标题
                    .setContentText("This is content text") // 设置通知内容
                    .setPriority(NotificationCompat.PRIORITY_DEFAULT) // 设置通知优先级
                    .setLargeIcon(BitmapFactory.decodeResource(getResources(), R.mipmap.ic_launcher)) // 设置大图标
                    .setWhen(System.currentTimeMillis()); // 设置通知时间

            NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
            notificationManager.notify(1, builder.build()); // 发送通知
        }
    }
}

现在可以为弹出的消息设置点击事件：

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
   

    private static final String CHANNEL_ID = "notification_channel";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
   
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button sendNotice = findViewById(R.id.send_notice);
        sendNotice.setOnClickListener(this);

        createNotificationChannel();
    }

    private void createNotificationChannel() {
   
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
   
            CharSequence name = "Notification Channel";
            String description = "Channel for notifications";
            int importance = NotificationManager.IMPORTANCE_DEFAULT;
            NotificationChannel channel = new NotificationChannel(CHANNEL_ID, name, importance);
            channel.setDescription(description);
            NotificationManager notificationManager = getSystemService(NotificationManager.class);
            notificationManager.createNotificationChannel(channel);
        }
    }

    @SuppressLint("NotificationPermission")
    @Override
    public void onClick(View v) {
   
        //点击通知后跳转页面
        Intent intent = new Intent(MainActivity.this,MainActivity2.class);
        PendingIntent pi = PendingIntent.getActivity(MainActivity.this, 0, intent, PendingIntent.FLAG_IMMUTABLE);


        //申请通知权限
        if (ContextCompat.checkSelfPermission(MainActivity.this,
                android.Manifest.permission.POST_NOTIFICATIONS) != PackageManager.PERMISSION_GRANTED) {
   
            ActivityCompat.requestPermissions(MainActivity.this, new String