Getting info from MTP device: "friendly name" is always empty

Question

I am using this project to fetch data via MTP:

https://github.com/notpod/wpd-lib

My problem: the "friendly name" of the device is always empty. Windows shows a friendly name under "This PC", so it should be feasible.

This is how the mentioned github project tries to retrieve the friendly name (from the file WindowsPortableDevice.cs):

var WPD_DEVICE_FRIENDLY_NAME = new PortableDeviceApiLib._tagpropertykey();
WPD_DEVICE_FRIENDLY_NAME.fmtid = new Guid(0x26D4979A, 0xE643, 0x4626, 0x9E, 0x2B, 0x73, 0x6D, 0xC0, 0xC9, 0x2F, 0xDC);
WPD_DEVICE_FRIENDLY_NAME.pid = 12;

string friendlyName;            
propertyValues.GetStringValue(ref DevicePropertyKeys.WPD_DEVICE_FRIENDLY_NAME, out friendlyName);                        

As stated before, the result of friendlyName is always empty.

---

What I have tried so far:

In this post I found this other possible solution, which uses the PortableDeviceManagerClass instead of the PortableDeviceClass:

string RetrieveFriendlyName(
                        PortableDeviceApiLib.PortableDeviceManagerClass PortableDeviceManager,
                        string PnPDeviceID)
{
    uint   cFriendlyName = 0;
    ushort[] usFriendlyName;
    string strFriendlyName = String.Empty;

    // First, pass NULL as the LPWSTR return string parameter to get the total number
    // of characters to allocate for the string value.
    PortableDeviceManager.GetDeviceFriendlyName(PnPDeviceID, null, ref cFriendlyName);

    // Second allocate the number of characters needed and retrieve the string value.

    usFriendlyName = new ushort[cFriendlyName];
    if (usFriendlyName.Length > 0)
    {
        PortableDeviceManager.GetDeviceFriendlyName(PnPDeviceID, usFriendlyName, ref cFriendlyName);

        // We need to convert the array of ushorts to a string, one
        // character at a time.
        foreach (ushort letter in usFriendlyName)
            if (letter != 0)
                strFriendlyName += (char)letter;

        // Return the friendly name
        return strFriendlyName;
    }
    else
        return null;
}

The problem here is that I seem to have a different signature of GetDeviceFriendlyName (different Interop.PortableDeviceApiLib.dll?). This is mine:

void GetDeviceFriendlyName(string pszPnPDeviceID, ref ushort pDeviceFriendlyName, ref uint pcchDeviceFriendlyName);

It does not accept null or ushort[].

I tested the following, just to see how it behaved:

var pDeviceFriendlyName = default(ushort);
var pcchDeviceFriendlyName = default(uint);
GetDeviceFriendlyName(pszPnPDeviceID, ref pDeviceFriendlyName, ref pcchDeviceFriendlyName);

...but it threw an exception: "The data is invalid. (Exception from HRESULT: 0x8007000D)".

Answer 1

Apparently Windows does not use "friendly name" to show the device on "This PC", but "device model" instead:

WPD_DEVICE_MODEL.fmtid = new Guid(0x26D4979A, 0xE643, 0x4626, 0x9E, 0x2B, 0x73, 0x6D, 0xC0, 0xC9, 0x2F, 0xDC);
WPD_DEVICE_MODEL.pid = 8;