您是否通过意图请求许可来查看附件？

您是定义自己的自定义类型和通信层还是试图通过adb ....这样做？更多信息可能会很好。但现在，您需要知道您是否可以看到该设备。

private void checkInfo() {

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

/*

* this block required if you need to communicate to USB devices it's

* take permission to device

* if you want than you can set this to which device you want to communicate

*/

// ------------------------------------------------------------------

mPermissionIntent = PendingIntent.getBroadcast(this, 0, new Intent(

ACTION_USB_PERMISSION), 0);

IntentFilter filter = new IntentFilter(ACTION_USB_PERMISSION);

registerReceiver(mUsbReceiver, filter);

// -------------------------------------------------------------------

HashMap deviceList = manager.getDeviceList();

Iterator deviceIterator = deviceList.values().iterator();

String i = "";

while (deviceIterator.hasNext()) {

device = deviceIterator.next();

manager.requestPermission(device, mPermissionIntent);

i += "\n" + "DeviceID: " + device.getDeviceId() + "\n"

+ "DeviceName: " + device.getDeviceName() + "\n"

+ "DeviceClass: " + device.getDeviceClass() + " - "

+ "DeviceSubClass: " + device.getDeviceSubclass() + "\n"

+ "VendorID: " + device.getVendorId() + "\n"

+ "ProductID: " + device.getProductId() + "\n";

}

textInfo.setText(i);

}

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 = (UsbDevice) intent

.getParcelableExtra(UsbManager.EXTRA_DEVICE);

if (intent.getBooleanExtra(

UsbManager.EXTRA_PERMISSION_GRANTED, false)) {

if (device != null) {

// call method to set up device communication

}

} else {

Log.d("ERROR", "permission denied for device " + device);

}

}

}

}

}; ：

https://source.android.com/devices/accessories/aoa2.html

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