Question

这是完整的代码。

    import ...

    public class MainActivity extends AppCompatActivity {

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

    public void notify(View view) {

     Toast.makeText(getApplicationContext(),"Clicked",Toast.LENGTH_LONG).show();
//shows the toast "Clicked"

        NotificationCompat.Builder mBuilder =
                new NotificationCompat.Builder(this)
                        .setSmallIcon(R.drawable.small)
                        .setContentTitle("My notification")
                        .setContentText("Hello World!");

        Intent notificationIntent = new Intent(this, MainActivity.class);
        PendingIntent contentIntent = PendingIntent.getActivity(this, 0, notificationIntent,
                PendingIntent.FLAG_UPDATE_CURRENT);
        mBuilder.setContentIntent(contentIntent);


        NotificationManager mNotificationManager =
                (NotificationManager) getSystemService(NOTIFICATION_SERVICE);

        mNotificationManager.notify(1, mBuilder.build());
        }
    }

我做错了什么？这不会创建任何通知。我是一个相当新的android并且自己学习。这是我第一次被困了很长时间。我到处搜索，所有的资源告诉我我已经做过的事情。请帮忙。

Answer 1

找到答案。

我的手机是奥利奥。我不得不使用通知渠道。这里提到的答案在具有较低版本的模拟器上运行得非常好。

使用[GitHub]（https://github.com/tutsplus/android-o-how-to-use-notification-channels）作为参考。

谢谢大家的回答。

Answer 2

您没有调用通知功能：

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    notify(); //Call here
   }
public void notify() //View is not used

{
// Rest of the code is same
Toast.makeText(getApplicationContext(), "Clicked", Toast.LENGTH_LONG).show();

//显示吐司＆＃34;点击＆＃34;

        NotificationCompat.Builder mBuilder =
                new NotificationCompat.Builder(this)
                        .setSmallIcon(R.drawable.ic_launcher_foreground)
                        .setContentTitle("My notification")
                        .setContentText("Hello World!");

        Intent notificationIntent = new Intent(this, MainActivity.class);
        PendingIntent contentIntent = PendingIntent.getActivity(this, 0, notificationIntent,
                PendingIntent.FLAG_UPDATE_CURRENT);
        mBuilder.setContentIntent(contentIntent);


        NotificationManager mNotificationManager =
                (NotificationManager) getSystemService(NOTIFICATION_SERVICE);

        mNotificationManager.notify(1, mBuilder.build());

    }

如果您使用

public void notify(View view) //View is required

{

然后调用：notify（null）;

否则只需要调用：notify（）;

会抛出以下异常 - ＆gt;

java.lang.IllegalMonitorStateException：在notify（）之前没有被线程锁定的对象

Notification Builder不会创建通知

2 个答案: