public void SendRequest (ref IOUSBDeviceRequest request)
{
ThrowIfDisposed ();
var result = Interface.DeviceRequest (InterfaceRef, ref request);
IOObject.ThrowIfError (result);
}
public Task<int> SendRequestAsync (IOUSBDeviceRequest request)
{
ThrowIfDisposed ();
var completionSource = new TaskCompletionSource<int> ();
GCHandle callbackHandle = new GCHandle ();
IOAsyncCallback1 callback = (refCon, callbackResult, arg0) => {
callbackHandle.Free ();
if (callbackResult == IOReturn.Success)
completionSource.TrySetResult ((int)arg0);
else
completionSource.TrySetException (callbackResult.ToNSErrorException ());
};
callbackHandle = GCHandle.Alloc (callback, GCHandleType.Pinned);
var result = Interface.DeviceRequestAsync (InterfaceRef, request, callback, IntPtr.Zero);
IOObject.ThrowIfError (result);
return completionSource.Task;
}
char[] GetStringDescriptor (byte index, int language)
{
// based on http://oroboro.com/usb-serial-number-osx/
const int maxUsbStringLength = 255;
var buffer = Marshal.AllocHGlobal (maxUsbStringLength);
try {
var request = new IOUSBDeviceRequest () {
Direction = EndpointDirection.In,
DeviceRequestType = DeviceRequestType.Standard,
Recipient = DeviceRequestRecipient.Device,
RequestType = RequestType.GetDescriptor,
Value = (ushort)((byte)DescriptorType.String << 8 | index),
Index = (ushort)language,
DataLength = maxUsbStringLength,
Data = buffer
};
var result = Interface.DeviceRequest (InterfaceRef, ref request);
ThrowIfError (result);
var header = (IOUSBDescriptorHeader)Marshal.PtrToStructure (buffer, typeof(IOUSBDescriptorHeader));
var dataLength = (header.Length - 1) / 2;
var data = new char[dataLength];
Marshal.Copy (buffer + 2, data, 0, dataLength);
return data;
} finally {
Marshal.FreeHGlobal (buffer);
}
}