Visual Basic

<DllImport("myCom.dll", CharSet:=CharSet.Unicode)> Public Function RFID_Comms(ByVal sTx As IntPtr, ByVal sRx As IntPtr, ByVal sRxSize As UShort, ByVal timeout As UShort) As Integer

<DllImport("myCom.dll", CharSet:=CharSet.Unicode)> Public Function RFID_Comms(ByVal sTx As IntPtr, ByVal sRx As IntPtr, ByVal sRxSize As UShort, ByVal timeout As UShort) As Integer
   End Function

sTx = Marshal.AllocHGlobal(100)
       sRx = Marshal.AllocHGlobal(300)
       sTx = StringToBSTR("RSD" & vbCr)
       result = RFID_Comms(sTx, sRx, 3000, 1000)
       lblOuput.Text = "Result: " & result
       txtBxOutput.Text = PtrToStringUni(sRx)

<DllImport("myCom.dll", CharSet:=CharSet.Unicode)> Function RFID_wGetVersion(ByVal s As IntPtr, ByVal size As UShort) As Integer
   End Function

Dim memString As String 
        Dim addrPTr As IntPtr = Marshal.AllocHGlobal(40) 
        res = RFIDP1_wGetVersion(addrPTr, 40)
        memString = PtrToStringUni(addrPTr)

        lblOuput.Text = "Result: " & res
        txtBxOutput.Text = memString
        lblOuput.Refresh()
        Marshal.FreeHGlobal(addrPTr)

Declare Function RFID_Comms Lib "myCom.dll" Alias "LibraryFunctionNameHere" (sTx As String, sRx As String, sRxSize As UShort, timeout As UShort)

Dave Kreskowiak wrote:

It's very strange to see Short integers being used where they are.

Public Declare Function RFIDP1_TagComms Lib "myCom.dll" Alias "RFIDP1_TagComms" (ByVal sTx As IntPtr, ByVal sRx As IntPtr, ByVal sRxSize As Integer, ByVal timeout As Integer) As Integer

tagRead = "SRD" 'various codes
Dim code() As Byte = System.Text.Encoding.ASCII.GetBytes(tagRead)
Dim codeLen As Integer = code.Length
'turn on rfid module!!!
result = PwrCtrl(1, True) 'targets separate PDA DLL
Threading.Thread.Sleep(500) 'allow power to stabilse
txtBxOutput.Text = "Module On"

Dim pointer As IntPtr = Marshal.AllocHGlobal(codeLen)
Marshal.Copy(code, 0, pointer, codeLen)
Dim sRx As IntPtr = Marshal.AllocHGlobal(127)
result = RFIDP1_TagComms(pointer, sRx, 127, 500)
If result = 0 Then
    lbltagResult.Text = "Tag Read"
Else
    lbltagResult.Text = result
End If
deCode(sRx)

Public Sub deCode(ByVal addr As IntPtr)
        'deCode the ascii code at the pointer
        Dim managedArray2(127) As Byte
        Marshal.Copy(addr, managedArray2, 0, 127)
        Dim enc As New System.Text.ASCIIEncoding() 'convert chars
        txtBxTN.Text = enc.GetString(managedArray2, 0, 18) 'to letters 
 End Sub

Public Class FrmDisplay

    Private Sub Label1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)

    End Sub

    Private Sub FrmDisplay_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Me.WindowState = FormWindowState.Maximized ' display fullscreem
    End Sub

    Private Sub BtnDisplayWord_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnDisplayWord.Click
        Dim words() As String = IO.File.ReadAllLines("words.txt")
        Dim query = From word In words
Order By VowelCount(word) Descending, word.Length Descending, word Ascending
Select VowelCount(word) & " " & word
            For Each word In Words
            ListResults.DataSource = query.ToList

            Next
    End Sub


    Private Sub BtnRetour_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnRetour.Click
        Me.Hide()
        frmMain.Show()
    End Sub
End Class