一、需求

在Android应该开发过程中，用到了USB通讯，需要应用监控USB设备的插入和拔出，从而刷新USB设备列表。

二、实现

在使用时，需要register和unregister。

通过UsbDevice device = (UsbDevice) intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);可以获取到USB设备信息。

public class USBBroadcastReceiver extends BroadcastReceiver {

    private OnUsbListener usbListener;

    @Override
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        if (UsbManager.ACTION_USB_DEVICE_DETACHED.equals(action) ||
                UsbManager.ACTION_USB_DEVICE_ATTACHED.equals(action)) {
            usbListener.onStateChanged();
        }
    }

    public void registerUsbReceiver(Context context) {
        IntentFilter filter = new IntentFilter();
        filter.addAction(UsbManager.ACTION_USB_DEVICE_ATTACHED);
        filter.addAction(UsbManager.ACTION_USB_DEVICE_DETACHED);
        context.registerReceiver(this, filter);
    }

    public void unregisterUsbReceiver(Context context) {
        context.unregisterReceiver(this);
    }

    public void setUsbListener(OnUsbListener usbListener) {
        this.usbListener = usbListener;
    }

    @FunctionalInterface
    public interface OnUsbListener {
        void onStateChanged();
    }
}