Android警报不起作用

我已经为此苦苦挣扎了好几个小时。我还检查了文档和几个主题。我在两个主题中找到了此代码，两个人都说该代码运行良好，但在我的计算机上却无法运行。第一个Toast出现了，但是第二个Toast却没有出现。怎么了？

public class HelloAndroid2 extends Activity {


@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    Intent intent = new Intent(this, AlarmReceiver.class);

    PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0,
    intent, PendingIntent.FLAG_ONE_SHOT);

    AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
    alarmManager.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + (10 * 1000), pendingIntent);
    Toast.makeText(this, "Alarm set", Toast.LENGTH_LONG).show();

}

 public final class AlarmReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        Toast.makeText(context, "Alarm worked.", Toast.LENGTH_LONG).show();

    }
 }

}

最佳答案

实际上，您不需要指定操作，因为您在 Intent 中使用了AlarmReceiver.class类。

在AndroidManifest.xml中，确保您在<application>标记中具有接收方定义，例如:
<receiver android:name="AlarmReceiver">
编辑:
好的，有两种使用广播接收器的方法。

1)从您提供的代码中，AlarmReceiver.java将包含:

public final class AlarmReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        Toast.makeText(context, "Alarm worked.", Toast.LENGTH_LONG).show();

    }
 }

和HelloAndroid2.java:

public class HelloAndroid2 extends Activity {


@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    Intent intent = new Intent(this, AlarmReceiver.class);

    PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0,
    intent, PendingIntent.FLAG_ONE_SHOT);

    AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
    alarmManager.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + (10 * 1000), pendingIntent);
    Toast.makeText(this, "Alarm set", Toast.LENGTH_LONG).show();

}

}

这样，您可以将广播接收器设置为使用AndroidManifest.xml和标记<receiver ...>
2)第二种方式。通过这种方式，您只能使用1个文件HelloWorld2.java:

在您的 Activity 中，创建您的广播接收器并注册。

public class HelloWorld2 extends Activity {
    private SharedPreferences prefs;
    private String mName;


    BroadcastReceiver alarmReceiver = new BroadcastReceiver() {

        @Override
        public void onReceive(Context context, Intent intent) {
            Toast.makeText(context, "Alarm worked", Toast.LENGTH_LONG).show();
        }
    };


    public static final String ACTION_NAME = "com.helloworld.MYACTION";
    private IntentFilter myFilter = new IntentFilter(ACTION_NAME);


    @Override
    protected void onPause() {
        unregisterReceiver(alarmReceiver);
        super.onPause();
    }

    @Override
    protected void onResume() {
        registerReceiver(alarmReceiver, myFilter);
        super.onResume();
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        registerReceiver(alarmReceiver, myFilter);

        Intent intent = new Intent(ACTION_NAME);

        PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0,
        intent, PendingIntent.FLAG_ONE_SHOT);

        AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
        alarmManager.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + (10 * 1000), pendingIntent);
        Toast.makeText(this, "Alarm set", Toast.LENGTH_LONG).show();


    }