How to make HLLAPI Code work in VB.Net

[Gowrisankarrs]

Hello everyone,

I'm trying to automate Rumba mainframe terminal through VB.Net.

I came to know that using EHLAPI32.dll this can be achieved. When I tried the code as an Excel macro, it works fine. But I have to make it work as a VB.Net code. When I converted the code to VB.Net, the code doesn't work. When I run in VB.Net, the return code is 2 whereas in Excel macro it is 0.

Excel Macro code:

Private Declare Function hllapi Lib "C:\Program Files (x86)\Micro Focus\RUMBA\System\ehlapi32.Dll" (Func%, ByVal Buffer$, bSize%, RetC%) As Long

Sub Main()

Dim Astr As String
Dim Alen As Integer
Dim RetC As Integer
Dim Func As Integer
Dim ReturnCode As Integer

Func = 1
Astr = "C"
Alen = Len(Astr)
ReturnCode = hllapi(Func, Astr, Alen, RetC)

Func = 3
Astr = "HELLO"
Alen = Len(Astr)
ReturnCode = hllapi(Func, Astr, Alen, RetC)

End Sub


VB.Net code:

Imports System.Runtime.InteropServices
Imports System.Text

Module Module1

Declare Function hllapi Lib "C:\Program Files (x86)\Micro Focus\RUMBA\System\ehlapi32.Dll" (lpwFunction As Int32, lpbyString As String, lpwLength As Int16, lpwReturnCode As Int16) As Int16

Sub Main()

Dim status As Int16
Dim rc As Int16

rc = hllapi(1, "C", 1, status) ' Connect to Presentation Space C
rc = hllapi(3, "HELLO", 5, status) ' Send key 'HELLO'

End Sub

End Module


Any guidance is deeply appreciated. Thanks.

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