java按下按钮并显示通知

Question

我在xml中有一个按钮，当它被单击时，下面的代码应该显示一个通知位，它没有运行，并给出一个错误（notification.Builder（new View.OnClickListener（）{}）是未定义的） 有人告诉我有什么问题吗

主要活动。爪哇

    package com.example.auto;
    public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    Button b =(Button) findViewById(R.id.button1);
    b.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {

Intent intent = new Intent(MainActivity.this, NotificationReceiver.class);
PendingIntent pIntent = PendingIntent.getActivity(MainActivity.this,
        0, intent, 0);

Notification mNotification = new Notification.Builder(this)

                .setContentTitle("New Post!")
                .setContentText("Here's an awesome update for you!")
                .setContentIntent(pIntent)
          .addAction(0, "View", pIntent)
           .addAction(0, "Remind", pIntent)
     .build();
NotificationManager notificationManager = (NotificationManager) 
        getSystemService(NOTIFICATION_SERVICE);
notificationManager.notify(0, mNotification);
}
    });
}
    }

Answer 1

试试这个：）

NotificationCompat.Builder mBuilder =
        new NotificationCompat.Builder(context)
        .setSmallIcon(R.drawable.ic_launcher)
        .setContentTitle("My notification")
        .setContentText("Hello World!");
// Creates an explicit intent for an Activity in your app
Intent resultIntent = new Intent(getApplicationContext(), MYDEMOACTIVITY.class);

// The stack builder object will contain an artificial back stack for the
// started Activity.
// This ensures that navigating backward from the Activity leads out of
// your application to the Home screen.
TaskStackBuilder stackBuilder = TaskStackBuilder.create(context);
// Adds the back stack for the Intent (but not the Intent itself)
stackBuilder.addParentStack(MYDEMOACTIVITY.class);
// Adds the Intent that starts the Activity to the top of the stack
stackBuilder.addNextIntent(resultIntent);
PendingIntent resultPendingIntent =
        stackBuilder.getPendingIntent(
            0,
            PendingIntent.FLAG_UPDATE_CURRENT
        );
mBuilder.setContentIntent(resultPendingIntent);
NotificationManager mNotificationManager =
    (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);

// mId allows you to update the notification later on.
mNotificationManager.notify(mId, mBuilder.build());

Answer 2

构造函数需要一个Context，而OnClickListener是noContext

更改此项：

Notification mNotification = new Notification.Builder(this)

致：

Notification mNotification = new Notification.Builder(MainActivity.this)

Answer 3

Notification mNotification = new Notification.Builder(this)

您不能将“this”用作上下文，因为使用它您引用的是新的OnClickListener，而不是您的活动

要获取封闭活动的上下文，必须使用MainActivity。这：

Notification mNotification = new Notification.Builder(MainActivity.this)