Android: Receive UsbDevice from intent

Question

I'm messing about with the USB host, and following the guidelines on the Android Developers site I've managed to create a Hello World that starts up once a particular USB device is plugged in. However, when I try and "...obtain the UsbDevice that represents the attached device from the intent" it returns null: ``` protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); Intent intent = new Intent(); UsbDevice device = (UsbDevice) intent.getParcelableExtra(UsbManager.EXTRA_DEVICE); // device is always null if (device == null){Log.i(TAG,"Null device");} ``` Here's my manifest: ```

Accepted Answer

When your application is (re-)started due to the USB device attach event, then the device is passed on to the intent when `onResume` is called. You can get to it using the `getParcelableExtra` method. For example:

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

Intent intent = getIntent();
    if (intent != null) {
        Log.d("onResume", "intent: " + intent.toString());
        if (intent.getAction().equals(UsbManager.ACTION_USB_DEVICE_ATTACHED)) {
            UsbDevice usbDevice = intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
            if (usbDevice != null) {
                Log.d("onResume", "USB device attached: name: " + usbDevice.getDeviceName());
```

Android: Receive UsbDevice from intent

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