I'm trying to use this library to read and write files to an Android phone, but when I make a call to device.TransferContentToDeviceFromStream, I get the following exception:
An unhandled exception of type 'System.AccessViolationException' occurred in PortableDevices.dll

Additional information: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.

Is there anything I need to do differently to make this work, or do you know what the issue might be?

Thanks

_deviceManager.GetDevices(ref deviceIds[0], ref count); returns just 1 device every time. https://code.msdn.microsoft.com/windowsdesktop/Portable-Devices-COM-API-fd4a5f7d/view/SourceCode here i get 2 devices instead of 1.

When using the function DownloadFile in a loop with multiple PortableDeviceFile:

1. It works fine on the first file
2. It throws an exception on the second file

The exception:

An unhandled exception of type 'System.Runtime.InteropServices.COMException' occurred in PortableDevices.dll

Additional information: The requested resource is in use. (Exception from HRESULT: 0x800700AA)

I thought that maybe sourceStream needed to be closed, but that does not seem feasible with the current. Here is the line of the exception, marked with // !!! EXCEPTION:

    public void DownloadFile(PortableDeviceFile file, string saveToPath)
    {
        IPortableDeviceContent content;
        this._device.Content(out content);

        IPortableDeviceResources resources;
        content.Transfer(out resources);

        PortableDeviceApiLib.IStream wpdStream;
        uint optimalTransferSize = 0;

        var property = new _tagpropertykey();
        property.fmtid = new Guid(0xE81E79BE, 0x34F0, 0x41BF, 0xB5, 0x3F, 0xF1, 0xA0, 0x6A, 0xE8, 0x78, 0x42);
        property.pid = 0;

        // !!! EXCEPTION (on the second file)
        resources.GetStream(file.Id, ref property, 0, ref optimalTransferSize, out wpdStream);

        var sourceStream = (System.Runtime.InteropServices.ComTypes.IStream)wpdStream;

        var filename = Path.GetFileName(file.Name);
        FileStream targetStream = new FileStream(Path.Combine(saveToPath, filename), FileMode.Create, FileAccess.Write);

        unsafe
        {
            var buffer = new byte[1024];
            int bytesRead;
            do
            {
                sourceStream.Read(buffer, 1024, new IntPtr(&bytesRead));
                targetStream.Write(buffer, 0, 1024);
            } while (bytesRead > 0);
            targetStream.Close();               
        }
    }

I have an Android 4.4.2 device that uses MSC to access files via usb (appears as a normal storage device in windows) however after I use the DownloadFile function I cannot delete or alter the file in any way until I unplug the device and plug it back in. The message I get in Explorer is "The action can't be completed because the file is open in WUDFHost.exe".

This has worked fine with an MTP device but I want to be able to use both interchangeably and this is the only issue stopping that.

@Duke-fleed - I would like to use your library in our app. I don't see a LICENSE file in the repro and would like to know how I may use the library. Can you add a LICENSE file? Thank you. @bbending626

I am trying to read and write files to an Android Device. I was hoping to use this api. Is there any example code on reading and writing files, seeing if a file exists, looking at directories beneath the root? Any he,p would be greatly appreciated.

al