@Override protected void onAttachedToWindow() { super.onAttachedToWindow(); if (!mAttached) { mAttached = true; IntentFilter filter = new IntentFilter(); filter.addAction(Intent.ACTION_TIME_TICK); filter.addAction(Intent.ACTION_TIME_CHANGED); filter.addAction(Intent.ACTION_TIMEZONE_CHANGED); filter.addAction(Intent.ACTION_CONFIGURATION_CHANGED); filter.addAction(Intent.ACTION_USER_SWITCHED); getContext().registerReceiver(mIntentReceiver, filter, null, getHandler()); } // NOTE: It's safe to do these after registering the receiver since the receiver always runs // in the main thread, therefore the receiver can't run before this method returns. // The time zone may have changed while the receiver wasn't registered, so update the Time mCalendar = Calendar.getInstance(TimeZone.getDefault()); // Make sure we update to the current time postDelayed(new Runnable() { @Override public void run() { updateClock(); } }, 1000); } private final BroadcastReceiver mIntentReceiver = new BroadcastReceiver() { @Override public void onReceive(Context context, Intent intent) { String action = intent.getAction(); if (action.equals(Intent.ACTION_TIMEZONE_CHANGED)) { String tz = intent.getStringExtra("time-zone"); mCalendar = Calendar.getInstance(TimeZone.getTimeZone(tz)); if (mClockFormat != null) { mClockFormat.setTimeZone(mCalendar.getTimeZone()); } } else if (action.equals(Intent.ACTION_CONFIGURATION_CHANGED)) { final Locale newLocale = getResources().getConfiguration().locale; if (! newLocale.equals(mLocale)) { mLocale = newLocale; mClockFormatString = ""; // force refresh } } updateClock(); } }; final void updateClock() { if (mDemoMode) return; mCalendar.setTimeInMillis(System.currentTimeMillis()); setText(getSmallTime()); }状态栏秒数还是没有变化，使用getSmallTimeWithSeconds()报错

这段代码是 Android 平台的 Java 代码，它是一个自定义 View 的实现，用于显示系统时间。在 View 的 onAttachedToWindow() 方法中，它注册了一个 BroadcastReceiver 监听系统时间、时区等变化，并在接收到广播时更新时间的显示。在 updateClock() 方法中，它使用 Calendar 类获取当前时间，并调用 getSmallTime() 方法获取时间的字符串表示，然后将其显示在 View 上。

至于你提到的 getSmallTimeWithSeconds() 方法报错的问题，需要查看具体的错误信息才能确定原因。可以先检查这个方法是否在代码中有定义，如果没有需要先定义。如果已经定义了，可以在调用这个方法时查看具体的错误信息，比如编译错误或运行时异常等。

相关问题

@Override protected void onAttachedToWindow() { super.onAttachedToWindow(); if (!mAttached) { mAttached = true; IntentFilter filter = new IntentFilter(); filter.addAction(Intent.ACTION_TIME_TICK); filter.addAction(Intent.ACTION_TIME_CHANGED); filter.addAction(Intent.ACTION_TIMEZONE_CHANGED); filter.addAction(Intent.ACTION_CONFIGURATION_CHANGED); filter.addAction(Intent.ACTION_USER_SWITCHED); getContext().registerReceiver(mIntentReceiver, filter, null, getHandler()); } // NOTE: It's safe to do these after registering the receiver since the receiver always runs // in the main thread, therefore the receiver can't run before this method returns. // The time zone may have changed while the receiver wasn't registered, so update the Time mCalendar = Calendar.getInstance(TimeZone.getDefault()); // Make sure we update to the current time postDelayed(new Runnable() { @Override public void run() { updateClock(); } }, 1000); } private final BroadcastReceiver mIntentReceiver = new BroadcastReceiver() { @Override public void onReceive(Context context, Intent intent) { String action = intent.getAction(); if (action.equals(Intent.ACTION_TIMEZONE_CHANGED)) { String tz = intent.getStringExtra("time-zone"); mCalendar = Calendar.getInstance(TimeZone.getTimeZone(tz)); if (mClockFormat != null) { mClockFormat.setTimeZone(mCalendar.getTimeZone()); } } else if (action.equals(Intent.ACTION_CONFIGURATION_CHANGED)) { final Locale newLocale = getResources().getConfiguration().locale; if (! newLocale.equals(mLocale)) { mLocale = newLocale; mClockFormatString = ""; // force refresh } } updateClock(); } }; final void updateClock() { if (mDemoMode) return; mCalendar.setTimeInMillis(System.currentTimeMillis()); setText(getSmallTime()); }

这段代码是一个更新状态栏时间的方法，其中通过注册广播监听器来监听时间变化的广播事件，包括时间变化、时区变化、配置变化等事件。当接收到广播事件时，会更新时间，并将其显示在状态栏上。

在方法中，首先会注册广播监听器，在接收到广播事件后，会根据事件类型进行相应的操作，如更新时区、更新时间格式等。然后会通过 postDelayed 方法延迟 1 秒钟调用 updateClock 方法，实现实时更新的效果。

如果状态栏时间没有实时更新，可能是因为注册的广播监听器没有收到时间变化的广播事件。可以检查是否正确注册了广播监听器，并且广播事件的类型是否正确。此外，还可以在方法中增加一些调试信息，查看是否有错误发生。

android 读卡器监听,在Android中开发智能卡读卡器

对于Android开发智能卡读卡器，可以使用Android提供的NFC功能或者USB接口进行读卡操作。

如果使用NFC功能，需要在AndroidManifest.xml中添加以下权限：

<uses-permission android:name="android.permission.NFC" />
<uses-feature android:name="android.hardware.nfc" android:required="true" />

同时在Activity中注册NFC事件：

public class MainActivity extends AppCompatActivity {

    private NfcAdapter nfcAdapter;

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

        nfcAdapter = NfcAdapter.getDefaultAdapter(this);
    }

    @Override
    protected void onResume() {
        super.onResume();

        Intent intent = new Intent(this, getClass());
        intent.addFlags(Intent.FLAG_RECEIVER_REPLACE_PENDING);
        PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, intent, 0);
        IntentFilter[] intentFilters = new IntentFilter[]{new IntentFilter(NfcAdapter.ACTION_TECH_DISCOVERED)};
        nfcAdapter.enableForegroundDispatch(this, pendingIntent, intentFilters, null);
    }

    @Override
    protected void onPause() {
        super.onPause();

        nfcAdapter.disableForegroundDispatch(this);
    }

    @Override
    protected void onNewIntent(Intent intent) {
        super.onNewIntent(intent);

        if (NfcAdapter.ACTION_TECH_DISCOVERED.equals(intent.getAction())) {
            Tag tag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
            // TODO: 处理读卡操作
        }
    }
}

如果使用USB接口，需要在AndroidManifest.xml中添加以下权限：

<uses-permission android:name="android.permission.USB_PERMISSION" />

同时在Activity中注册USB事件：

public class MainActivity extends AppCompatActivity {

    private UsbManager usbManager;
    private PendingIntent pendingIntent;

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

        usbManager = (UsbManager) getSystemService(Context.USB_SERVICE);

        Intent intent = new Intent(this, getClass());
        pendingIntent = PendingIntent.getActivity(this, 0, intent, 0);
    }

    @Override
    protected void onResume() {
        super.onResume();

        IntentFilter filter = new IntentFilter();
        filter.addAction(UsbManager.ACTION_USB_DEVICE_ATTACHED);
        filter.addAction(UsbManager.ACTION_USB_DEVICE_DETACHED);
        registerReceiver(usbReceiver, filter);
    }

    @Override
    protected void onPause() {
        super.onPause();

        unregisterReceiver(usbReceiver);
    }

    private BroadcastReceiver usbReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            if (UsbManager.ACTION_USB_DEVICE_ATTACHED.equals(action)) {
                UsbDevice device = intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
                if (usbManager.hasPermission(device)) {
                    // TODO: 处理读卡操作
                } else {
                    usbManager.requestPermission(device, pendingIntent);
                }
            } else if (UsbManager.ACTION_USB_DEVICE_DETACHED.equals(action)) {
                // TODO: 处理设备断开操作
            }
        }
    };
}

需要注意的是，USB读卡器需要在Android设备中安装驱动程序，以便能够正确识别设备并进行读卡操作。