Async Read/Write

using System;
using System.Collections.Generic;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading;
using LibUsbDotNet;
using LibUsbDotNet.Internal;
using LibUsbDotNet.Main;
using LibUsbDotNet.LudnMonoLibUsb;

namespace Examples
{
    internal class ReadWriteAsync
    {
        public static UsbDevice MyUsbDevice;

        #region SET YOUR USB Vendor and Product ID!

        public static UsbDeviceFinder MyUsbFinder = new UsbDeviceFinder(1234, 1);

        #endregion

        public static void Main(string[] args)
        {
            ErrorCode ec = ErrorCode.None;
            try
            {
                // Find and open the usb device.
                MyUsbDevice = UsbDevice.OpenUsbDevice(MyUsbFinder);

                // If the device is open and ready
                if (MyUsbDevice == null) throw new Exception("Device Not Found.");

                // If this is a "whole" usb device (libusb-win32, linux libusb)
                // it will have an IUsbDevice interface. If not (WinUSB) the 
                // variable will be null indicating this is an interface of a 
                // device.
                IUsbDevice wholeUsbDevice = MyUsbDevice as IUsbDevice;
                if (!ReferenceEquals(wholeUsbDevice, null))
                {
                    // This is a "whole" USB device. Before it can be used, 
                    // the desired configuration and interface must be selected.

                    // Select config #1
                    wholeUsbDevice.SetConfiguration(1);

                    // Claim interface #0.
                    wholeUsbDevice.ClaimInterface(0);
                }

                // open read endpoint 1.
                UsbEndpointReader reader = MyUsbDevice.OpenEndpointReader(ReadEndpointID.Ep01);

                // open write endpoint 1.
                UsbEndpointWriter writer = MyUsbDevice.OpenEndpointWriter(WriteEndpointID.Ep01);

                // the write test data.
                string testWriteString = "ABCDEFGH";

                ErrorCode ecWrite;
                ErrorCode ecRead;
                int transferredOut;
                int transferredIn;
                UsbTransfer usbWriteTransfer;
                UsbTransfer usbReadTransfer;
                byte[] bytesToSend = Encoding.Default.GetBytes(testWriteString);
                byte[] readBuffer = new byte[1024];
                int testCount = 0;
                do
                {
                    // Create and submit transfer
                    ecRead = reader.SubmitAsyncTransfer(readBuffer, 0, readBuffer.Length, 100, out usbReadTransfer);
                    if (ecRead != ErrorCode.None) throw new Exception("Submit Async Read Failed.");

                    ecWrite = writer.SubmitAsyncTransfer(bytesToSend, 0, bytesToSend.Length, 100, out usbWriteTransfer);
                    if (ecWrite != ErrorCode.None)
                    {
                        usbReadTransfer.Dispose();
                        throw new Exception("Submit Async Write Failed.");
                    }

                    WaitHandle.WaitAll(new WaitHandle[] { usbWriteTransfer.AsyncWaitHandle, usbReadTransfer.AsyncWaitHandle },200,false);
                    if (!usbWriteTransfer.IsCompleted) usbWriteTransfer.Cancel();
                    if (!usbReadTransfer.IsCompleted) usbReadTransfer.Cancel();

                    ecWrite = usbWriteTransfer.Wait(out transferredOut);
                    ecRead = usbReadTransfer.Wait(out transferredIn);

                    usbWriteTransfer.Dispose();
                    usbReadTransfer.Dispose();

                    Console.WriteLine("Read  :{0} ErrorCode:{1}", transferredIn, ecRead);
                    Console.WriteLine("Write :{0} ErrorCode:{1}", transferredOut, ecWrite);
                    Console.WriteLine("Data  :" + Encoding.Default.GetString(readBuffer, 0, transferredIn));
                    testCount++;
                } while (testCount < 5);
                Console.WriteLine("\r\nDone!\r\n");
            }
            catch (Exception ex)
            {
                Console.WriteLine();
                Console.WriteLine((ec != ErrorCode.None ? ec + ":" : String.Empty) + ex.Message);
            }
            finally
            {
                if (MyUsbDevice != null)
                {
                    if (MyUsbDevice.IsOpen)
                    {
                        // If this is a "whole" usb device (libusb-win32, linux libusb-1.0)
                        // it exposes an IUsbDevice interface. If not (WinUSB) the 
                        // 'wholeUsbDevice' variable will be null indicating this is 
                        // an interface of a device; it does not require or support 
                        // configuration and interface selection.
                        IUsbDevice wholeUsbDevice = MyUsbDevice as IUsbDevice;
                        if (!ReferenceEquals(wholeUsbDevice, null))
                        {
                            // Release interface #0.
                            wholeUsbDevice.ReleaseInterface(0);
                        }

                        MyUsbDevice.Close();
                    }
                    MyUsbDevice = null;

                    // Free usb resources
                    UsbDevice.Exit();
                }

                // Wait for user input..
                Console.ReadKey();
            }
        }
    }
}

Imports System
Imports System.Collections.Generic
Imports System.Text
Imports System.Text.RegularExpressions
Imports System.Threading
Imports LibUsbDotNet
Imports LibUsbDotNet.Internal
Imports LibUsbDotNet.Main
Imports LibUsbDotNet.LudnMonoLibUsb

Namespace Examples
    Friend Class ReadWriteAsync
        Public Shared MyUsbDevice As UsbDevice

        #Region "SET YOUR USB Vendor and Product ID!"

        Public Shared MyUsbFinder As New UsbDeviceFinder(1234, 1)

        #End Region

        Public Shared Sub Main(args As String())
            Dim ec As ErrorCode = ErrorCode.None
            Try
                ' Find and open the usb device.
                MyUsbDevice = UsbDevice.OpenUsbDevice(MyUsbFinder)

                ' If the device is open and ready
                If MyUsbDevice Is Nothing Then
                    Throw New Exception("Device Not Found.")
                End If

                ' If this is a "whole" usb device (libusb-win32, linux libusb)
                ' it will have an IUsbDevice interface. If not (WinUSB) the 
                ' variable will be null indicating this is an interface of a 
                ' device.
                Dim wholeUsbDevice As IUsbDevice = TryCast(MyUsbDevice, IUsbDevice)
                If Not ReferenceEquals(wholeUsbDevice, Nothing) Then
                    ' This is a "whole" USB device. Before it can be used, 
                    ' the desired configuration and interface must be selected.


                    ' Select config #1
                    wholeUsbDevice.SetConfiguration(1)

                    ' Claim interface #0.
                    wholeUsbDevice.ClaimInterface(0)
                End If

                ' open read endpoint 1.
                Dim reader As UsbEndpointReader = MyUsbDevice.OpenEndpointReader(ReadEndpointID.Ep01)

                ' open write endpoint 1.
                Dim writer As UsbEndpointWriter = MyUsbDevice.OpenEndpointWriter(WriteEndpointID.Ep01)

                ' the write test data.
                Dim testWriteString As String = "ABCDEFGH"

                Dim ecWrite As ErrorCode
                Dim ecRead As ErrorCode
                Dim transferredOut As Integer
                Dim transferredIn As Integer
                Dim usbWriteTransfer As UsbTransfer
                Dim usbReadTransfer As UsbTransfer
                Dim bytesToSend As Byte() = Encoding.[Default].GetBytes(testWriteString)
                Dim readBuffer As Byte() = New Byte(1023) {}
                Dim testCount As Integer = 0
                Do
                    ' Create and submit transfer
                    ecRead = reader.SubmitAsyncTransfer(readBuffer, 0, readBuffer.Length, 100, usbReadTransfer)
                    If ecRead <> ErrorCode.None Then
                        Throw New Exception("Submit Async Read Failed.")
                    End If

                    ecWrite = writer.SubmitAsyncTransfer(bytesToSend, 0, bytesToSend.Length, 100, usbWriteTransfer)
                    If ecWrite <> ErrorCode.None Then
                        usbReadTransfer.Dispose()
                        Throw New Exception("Submit Async Write Failed.")
                    End If

                    WaitHandle.WaitAll(New WaitHandle() {usbWriteTransfer.AsyncWaitHandle, usbReadTransfer.AsyncWaitHandle}, 200, False)
                    If Not usbWriteTransfer.IsCompleted Then
                        usbWriteTransfer.Cancel()
                    End If
                    If Not usbReadTransfer.IsCompleted Then
                        usbReadTransfer.Cancel()
                    End If

                    ecWrite = usbWriteTransfer.Wait(transferredOut)
                    ecRead = usbReadTransfer.Wait(transferredIn)

                    usbWriteTransfer.Dispose()
                    usbReadTransfer.Dispose()

                    Console.WriteLine("Read  :{0} ErrorCode:{1}", transferredIn, ecRead)
                    Console.WriteLine("Write :{0} ErrorCode:{1}", transferredOut, ecWrite)
                    Console.WriteLine("Data  :" & Encoding.[Default].GetString(readBuffer, 0, transferredIn))
                    testCount += 1
                Loop While testCount < 5
                Console.WriteLine(vbCr & vbLf & "Done!" & vbCr & vbLf)
            Catch ex As Exception
                Console.WriteLine()
                Console.WriteLine((If(ec <> ErrorCode.None, ec & ":", [String].Empty)) & ex.Message)
            Finally
                If MyUsbDevice IsNot Nothing Then
                    If MyUsbDevice.IsOpen Then
                        ' If this is a "whole" usb device (libusb-win32, linux libusb-1.0)
                        ' it exposes an IUsbDevice interface. If not (WinUSB) the 
                        ' 'wholeUsbDevice' variable will be null indicating this is 
                        ' an interface of a device; it does not require or support 
                        ' configuration and interface selection.
                        Dim wholeUsbDevice As IUsbDevice = TryCast(MyUsbDevice, IUsbDevice)
                        If Not ReferenceEquals(wholeUsbDevice, Nothing) Then
                            ' Release interface #0.
                            wholeUsbDevice.ReleaseInterface(0)
                        End If

                        MyUsbDevice.Close()
                    End If
                    MyUsbDevice = Nothing

                    ' Free usb resources
                    UsbDevice.[Exit]()
                End If

                ' Wait for user input..
                Console.ReadKey()
            End Try
        End Sub
    End Class
End Namespace