UnoPlatform Android Grant Permission to open USB port

Question

I'm developing an Android application with unoplatform that communicates with an external hardware by virtual serial port CP2102 silab connector.

The app would be shown into a Kiosk, so our goal is to grant USB Permission only one time in order to avoid to ask it to the final user.

1. I have tried to use Intent Filter like this

MainActivity.cs

[Activity(
        MainLauncher = true, ScreenOrientation = ScreenOrientation.Portrait,
        DirectBootAware = true,
        ConfigurationChanges = global::Uno.UI.ActivityHelper.AllConfigChanges,
        WindowSoftInputMode = SoftInput.AdjustPan | SoftInput.StateHidden
    )]
[IntentFilter(new[] { UsbManager.ActionUsbDeviceAttached })]
[MetaData(UsbManager.ActionUsbDeviceAttached, Resource = "@xml/device_filter")]

device_filter.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
  <!-- 0x10C4 / 0xEA60: CP210x UART Bridge -->
  <usb-device vendor-id="4292" product-id="60000" />
</resources>

but it doesn't work. App starts with connector attached but permission is not granted and it failed to open the port

2. I have tried to use RequestPermission like this:

Main.cs

UsbReciever usbReciever = new UsbReciever();
PendingIntent mPermissionIntent = PendingIntent.GetBroadcast(Context, 0, new Intent(ACTION_USB_PERMISSION), 0);
IntentFilter filter = new IntentFilter(ACTION_USB_PERMISSION);
RegisterReceiver(usbReciever, filter);

foreach (var dev in manager.DeviceList)
{
    if (dev.Value.VendorId == 4292)
        device = dev.Value;
}
if (device != null)
{
    manager.RequestPermission(device, mPermissionIntent);
    bool hasPermision = manager.HasPermission(device);
    while (!hasPermision)
    {
        hasPermision = manager.HasPermission(device);
        Thread.Sleep(3000);
    }
    //var usbDC = manager.OpenDevice(device);
}
else
{
    Toast.MakeText(this, "Unable to find serial port", ToastLength.Long).Show();
    // TODO: restart application
}

It workerd, but when I reboot Android device, the App asks again Permission to use Cp2102 connector and I'd like to avoid this.

Does UnoPlatform recognizes IntentFilter? Can someone help me find a solution?

A google search brought this: https://stackoverflow.com/questions/28137280/how-to-grant-permission-to-open-usb-device-with-usb-manager-opendevice-always - https://stackoverflow.com/questions/13647547/android-usb-automatically-grant-permission — Rand Random, May 26 '21 at 09:13
@RandRandom that solution uses manager.RequestPermission(device, mPermissionIntent); like my second solution — Emanuele Leoni, May 26 '21 at 09:52

UnoPlatform Android Grant Permission to open USB port

0 Answers0