Creating a DLL 32bit in VS for sending files by HTTPS

[Roger Cabo]

Hi everyone,

I'm interesting to send a file by https to a Webserver. The only was seems to be creating a dll 32bit and load into GB32.
The PHP web server stuff is also quite easy.. because both stuff can be done my chatGPT.

VS2022 free community edition is able to run .NET Framework 4.8 or 4.5

But here is a ugly thing. Loading the DLL 32bit into GB32 is tricky anyhow.
Anything seems to be different in case of old DLL's was created in the past of older 32bit windows systems.

Doe anyone has written a DLL and load into GB32 in VS community 2019 + NET 4.7.2
An easy way is to use :


// .NET Framework 4.7.2  is required on Win10
using System.Runtime.InteropServices;
using RGiesecke.DllExport;

namespace GB32_DLL_NET
{
   public class MessageBoxHelper
   {
       [DllExport("ShowMessageBox", CallingConvention = CallingConvention.StdCall)]
       public static void ShowMessageBox(string fileName, string serverAddress, string user, string loginPassword)
       {
           string message = $"File Name: {fileName}\nServer Address: {serverAddress}\nUser: {user}\nPassword: {loginPassword}";
           System.Windows.Forms.MessageBox.Show(message, "Test Message");
       }
   }
}


But this cause a error in VS, because the RGiesecke.DllExport doesnt seems to work with NET 4.7.2.

---

Then later we call in GB32 only to see if the process works..

Declare Sub ShowMessageBox Lib "GB32_DLL_NET.dll" Alias "ShowMessageBox" (ByVal fileName As String, ByVal serverAddress As String, ByVal user As String, ByVal loginPassword As String)

Sub IrgendwasHttps()
   Dim ret As Integer
   ShowMessageBox ("testfile.txt", "https://myserver.com", "myuser", "mypassword")
End Sub

The dll exist beside the gfabasic32.exe as GB32_DLL_NET.dll and was found!

But this happen all the time..
 

Any idea?

[Roger Cabo]

Mar 27, 2024 23:44:48 GMT 1 (X) said:

Is it as simple as using one of these instead: Message, MsgBox & MsgBox0 Commands and Functions

I'm trying to make a 32-bit DLL that uses .NET Framework 4.7.2 to securely send files to a web server.
However, when I try to call functions in this DLL from GFA-BASIC 32 using Declare Sub or Declare Func, GFA-BASIC 32 can't find any of the entry points.
This is because the DLL is object-based (using .NET) and not a native DLL, which seems to be causing compatibility issues with GFA-BASIC 32.

Here's what I've been attempting to do: I want GFA-BASIC 32 to call a function in the DLL, like so:

Declare Sub ShowMessageBox Lib "GB32_DLL_NET.dll" Alias "ShowMessageBox" (ByVal fileName As String, ByVal serverAddress As String, ByVal user As String, ByVal loginPassword As String)


Or, using a completely arbitrary function name:

Declare Sub MY_EntryPoint Lib "GB32_DLL_NET.dll" Alias "MY_EntryPoint" (ByVal fileName As String, ByVal serverAddress As String, ByVal user As String, ByVal loginPassword As String)

The goal is simply to display the strings passed from GFA-BASIC 32 inside the DLL using a message box inside the DLL. To make sure the DLL receives the strings correctly fro GB32.

System.Windows.Forms.MessageBox.Show(message, "Test Message");

This approach requires .NET Framework 4.7.2 on Windows 10 and involves using the RGiesecke's DllExport to create an entry point in the DLL:

using System.Runtime.InteropServices;
using RGiesecke.DllExport;

namespace GB32_DLL_NET   // The namespace can be anything
{
   public class NetFromGB32 // The class name can be anything
   {
// The function should be called from GB32. But GB32 does not find!
       [DllExport("MY_EntryPoint", CallingConvention = CallingConvention.StdCall)]

       public static void MY_EntryPoint(string fileName, string serverAddress, string user, string loginPassword)  
       {
           string message = $"File Name: {fileName}\nServer Address: {serverAddress}\nUser: {user}\nPassword: {loginPassword}";
           System.Windows.Forms.MessageBox.Show(message, "Test Message");
       }
   }
}
GB32 Code:

Declare Sub MY_EntryPoint Lib "GB32_DLL_NET.dll" Alias "ShowMessageBox" (ByVal fileName As String, ByVal serverAddress As String, ByVal user As String, ByVal loginPassword As String)

Sub IrgendwasHttps()
   Dim ret As Integer
   MY_EntryPoint ("testfile.txt", "https://myserver.com", "myuser", "mypassword")
End Sub

No more code is required to create the dll ... and the code in gb32!

But unfortunately GB32 doesn't find the Sub/func by : Declare Sub MY_EntryPoint Lib .....

Some years ago Sjouke wrote anywhere to use StdCall()() +8 Bytes..
But I didn't know where and in what context exactly.

[(X)]

Did you register the new DLL?

for example: regsvr32 FileName.dll

[Roger Cabo]

The problem is: VS2022 throw errors while building the 32bit DLL, containing using RGiesecke.DllExport; and Net 4.6 and above..

[Roger Cabo]

A) Could it be possible that this description has a bug in the Help file?
How can a function in c# access the address from ByVal lpBuffer As String ?

If pass ByRef lpBuffer As String, then it seems to be correct.. or?


Declare Help file:


Example
Declare Function  GetUserName Lib "advapi32.dll" Alias "GetUserNameA" (ByVal lpBuffer As String, nSize As Long) As Long
Declare FunctionA GetUserName Lib "advapi32.dll" (ByVal lpBuffer As String, nSize As Long) As Long
'
Dim uname As String = String(30, 0)
GetUserName(uname, 30)
Print ZTrim(uname)


B) What does FunctionA instead of Function ?

[(X)]

My guess: 'A' usually refers to ANSI character encoding.

[Roger Cabo]

I have good news.. I got the c# Net 4.8 DLL in GB32 to work. But its a bit tricky to pass a file asynchronous into GB32..

private static async Task<string> GetHTTPSFileAsync(string url, int maxData)


With .NET Framework 4.8, you can expand the capabilities of GFA-BASIC 32 by creating DLLs for various tasks:

Secure Online Server File Transfer: As demonstrated, create services to upload or download files to/from servers using HTTPS.
Databases: Interact with SQL databases or other types of databases, perform queries, and manage data.
Bluetooth and WiFi Communication: Develop applications that communicate with devices over Bluetooth or WiFi, useful for IoT projects or local network communications.
Machine Learning: With ML.NET, you can create machine learning models to predict customer behavior, classify text, or recognize images. You could develop a .NET DLL that uses predictive models for such tasks. This DLL could then be called from GFA-BASIC 32 to perform analyses or make predictions based on data from your BASIC application.

Each of these scenarios involves creating a .NET DLL that exposes specific functionalities (like file transfer, database access, or device communication),
which GFA-BASIC 32 can then call into, significantly extending what you can achieve with GFA-BASIC 32 alone.