无法在 android 上检测到 USB 连接

Question

我有一个 android 5.1.1 设备、一根 OTG 电缆和一个 ACS 读卡器。我想检测读卡器何时通过 OTG 电缆插入。我可以检测到DETACH，但ATTACH 没有运气。

这是我所拥有的：

清单文件：

<uses-feature android:name="android.hardware.usb.host" />

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">
    <activity
        android:name=".MainActivity"
        android:label="@string/app_name"
        android:theme="@style/AppTheme.NoActionBar">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <action android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>

        <meta-data
            android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED"
            android:resource="@xml/device_filter" />
    </activity>
</application>

XML 过滤器文件：

<?xml version="1.0" encoding="utf-8"?>

<resources>
    <!--usb-device vendor-id="1234" product-id="5678" class="255" subclass="66" protocol="1" /-->
    <usb-device />
</resources>

主活动：

private static final String TAG = MainActivity.class.getSimpleName();

private static final String ACTION_USB_PERMISSION = "com.guness.deleteme.USB_PERMISSION";
private final BroadcastReceiver mUsbReceiver = new BroadcastReceiver() {

    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        if (ACTION_USB_PERMISSION.equals(action)) {
            synchronized (this) {
                UsbDevice device = intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);

                if (intent.getBooleanExtra(UsbManager.EXTRA_PERMISSION_GRANTED, false)) {
                    if (device != null) {
                        //call method to set up device communication
                        Log.e(TAG, "permission granted " + device);
                    }
                } else {
                    Log.e(TAG, "permission denied for device " + device);
                }
            }
        }
    }
};

private PendingIntent mPermissionIntent;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    Log.e(TAG, "onCreate");
    setContentView(R.layout.activity_main);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    mPermissionIntent = PendingIntent.getBroadcast(this, 0, new Intent(ACTION_USB_PERMISSION), 0);
    IntentFilter filter = new IntentFilter(ACTION_USB_PERMISSION);
    registerReceiver(mUsbReceiver, filter);
}

@Override
protected void onResume() {
    super.onResume();
    Log.e(TAG, "onResume");
}

@Override
protected void onNewIntent(Intent intent) {
    super.onNewIntent(intent);
    Log.e(TAG, "onNewIntent");
}

我还没有请求许可，我会在检测到时询问。无论如何我都看不到预期的日志。

好吧，我检查了鼠标和 USB 记忆棒；也无法检测到它们。 安卓设备支持OTG、读卡器；与其他应用程序检查。我猜他们有计时器定期检查是否连接了 USB 设备。

Answer 1

尝试通过可编程的方式创建意图过滤器：

1) 删除

<action android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED" />

和

<meta-data
            android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED"
            android:resource="@xml/device_filter" />

Manifest 文件中的行（也可以删除 XML Filter 文件）

2) 在 MainActivity 中创建 IntentFilter（类似这样）：

private static final String TAG = MainActivity.class.getSimpleName();

private final BroadcastReceiver mUsbReceiver = new BroadcastReceiver() {

    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        if (UsbManager.ACTION_USB_DEVICE_ATTACHED.equals(action)) {
            Log.d(TAG, "USB device attached");

        } else if (UsbManager.ACTION_USB_DEVICE_DETACHED.equals(action)) {
            Log.d(TAG, "USB device detached");
        }
    }
};

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    Log.e(TAG, "onCreate");
    setContentView(R.layout.activity_main);

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

3) 使用权限

UsbManager.ACTION_USB_DEVICE_ATTACHED.equals(action)

案例。