如何从AlarmManager BroadcastReceiver调用MainActivity方法？

public class MyBroadcastReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        // 在这里执行需要调用的方法
        callMainActivityMethod();
    }

    private void callMainActivityMethod() {
        // 调用MainActivity中的方法
        MainActivity.myMethod();
    }
}

IntentFilter filter = new IntentFilter("com.example.ACTION_CALL_METHOD");
MyBroadcastReceiver receiver = new MyBroadcastReceiver();
registerReceiver(receiver, filter);

public class MyAlarmReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        // 发送广播
        Intent broadcastIntent = new Intent("com.example.ACTION_CALL_METHOD");
        context.sendBroadcast(broadcastIntent);
    }
}

<receiver android:name=".MyAlarmReceiver" />
<activity android:name=".MainActivity" />