android studio 30天学习笔记 -day 4-Notification

Notification一般会在手机上方的通知栏显示，举例来说，就像平时常用的line别人传送过来的讯息或是简讯，在不开启app的情况下，能从手机上方看见通知讯息的内容，在生活中可说是相当便利的功能。

今天会用Notification实作一个自我接收的通知，通知的讯息是用editText输入显示，按下button送出此通知内容

建立NotificationChannel

public void createNotificationChannel(){ //初始化NotificationManager
        manager=(NotificationManager)getSystemService(NOTIFICATION_SERVICE);
        //创建NotificationChannel(String id,CharSequence name,int importance)对象
        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
            NotificationChannel channel = new NotificationChannel(ChannelID,ChannelName, NotificationManager.IMPORTANCE_HIGH);
            manager.createNotificationChannel(channel);
        }
    }

建立NotificationCompat.Builder

 public NotificationCompat.Builder getNotificationChannelBuilder(String msg){//创建通知相关设定
        PendingIntent pendingIntent=PendingIntent.getActivity(this,
                0,new Intent(this,MainActivity.class)
                ,PendingIntent.FLAG_CANCEL_CURRENT);
        return builder =new NotificationCompat.Builder(this,ChannelID)
                .setContentTitle("message")
                .setContentText(msg)
                .setSmallIcon(R.drawable.ic_launcher_foreground)//必填
                .setContentIntent(pendingIntent)
                .setAutoCancel(true);
    }

setContentTitle:设定通知标题
setContentText:设定通知内容
setSmallIcon:设定小图标，一定要填
setContentIntent:设定使用者点击通知时要触发的 intent 行为
setAutoCancel:让通知在使用者点击通知时自动移除

NotificationManager
是android系统负责管理及发送的类别

manager=(NotificationManager)getSystemService(NOTIFICATION_SERVICE);

notify
发出通知

manager.notify(1, builder.build());

MainActivity完整程序码

public class MainActivity2 extends AppCompatActivity {
    private EditText editText;
    public static final String ChannelID="myChannel";
    public static final String ChannelName ="eles";
    private NotificationManager manager;
    private NotificationCompat.Builder builder;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
        editText=findViewById(R.id.edit1);
        createNotificationChannel();//创建频道

    }
    //按钮send监听事件
    public void send(View view) { //送出通知
        sendNotificationMsg();
    }
    public void createNotificationChannel(){ //初始化NotificationManager
        manager=(NotificationManager)getSystemService(NOTIFICATION_SERVICE);
        //创建NotificationChannel(String id,CharSequence name,int importance)对象
        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
            NotificationChannel channel = new NotificationChannel(ChannelID,ChannelName, NotificationManager.IMPORTANCE_HIGH);
            manager.createNotificationChannel(channel);
        }
    }
    
    private void sendNotificationMsg() {
        //判断editText有没有输入值
        if (!editText.getText().toString().isEmpty()) {
            builder = getNotificationChannelBuilder(editText.getText().toString());//发出的通知内容是editText输入的字
            manager.notify(1, builder.build());
        }
        else{
            Toast.makeText(this,"不能空白",Toast.LENGTH_LONG).show();
        }
    }

    public NotificationCompat.Builder getNotificationChannelBuilder(String msg){//创建通知相关设定
        PendingIntent pendingIntent=PendingIntent.getActivity(this,
                0,new Intent(this,MainActivity.class)
                ,PendingIntent.FLAG_CANCEL_CURRENT);
        return builder =new NotificationCompat.Builder(this,ChannelID)
                .setContentTitle("message")
                .setContentText(msg)
                .setSmallIcon(R.drawable.ic_launcher_foreground)//必填
                .setContentIntent(pendingIntent)
                .setAutoCancel(true);
    }
}

结果