• 0

[VB.NET] Memory Address


Question

9 answers to this question

Recommended Posts

  • 0

There was something known as the VarPtr function in VB (actually, in the BASIC language itself), but after some quick Googling, it isn't found in VB.NET, most likely due to the fact that it is "unmanaged". You might try digging something up along the lines of a VB.NET VarPtr replacement, however. For example, I found something with System.Runtime.InteropServices.GCHandle as well as something called BitConverter. I'm out of my element when it comes to .NET, but I figured that might help to get you started at least. Those last two seem wrong for memory, but I didn't look them up so they might be able to manipulate memory, despite their names.

  • 0

I wouldn't suggest messing with a .NET process' memory (due to CRL and other unpredictable aspects) so you should probably stick with other dummy processes and I'm not sure if .NET offers memory reading APIs either, so you'd probably be best using WinAPI in this:

Just look into OpenProcess, ReadProcessMemory, WriteProcessMemory, etc.

  • 0
  x0r said:
I wouldn't suggest messing with a .NET process' memory (due to CRL and other unpredictable aspects) so you should probably stick with other dummy processes and I'm not sure if .NET offers memory reading APIs either, so you'd probably be best using WinAPI in this:

Just look into OpenProcess, ReadProcessMemory, WriteProcessMemory, etc.

ReadProcessMemory, how would I do that?

Maybe something like this?

Imports System
Imports System.Diagnostics
Imports System.ComponentModel

Sub ReadMem()
Dim myProcesses As Process = Process.GetProcessesByName(pinball)
Dim memRead as String = myProcesses.ReadProcessMemory

Anything close to what your thinking?

  • 0

VB.NET doesn't natively supported memory pointers and allocations, but this can be accomplished through .NET Framework classes like IntPtr, Marshal and GCHandle. There are probably other types as well, but I've never used them.

IntPtr is used as a pointer to a platform-specific integer. Marshal can read and write data at a specific memory location (leveraging IntPtr's).

Example:

Dim pointer as IntPtr
Dim number as Integer = 20
pointer = Marshal.AllocHGlobal(4)
Marshal.WriteInt32(pointer, number)

Example:

Dim anotherInteger as Integer = Marshal.ReadInt32(pointer)

Example:

Dim message as String = "I know, I'm awesome..."
Dim pointer as IntPtr = Marshal.StringToHGlobalAuto(message)

Example:

Dim anotherMessage as String = Marshal.PtrToStringAuto(pointer)

You can see that the Marshal class acts as a broker between the program code and the memory operation.

You can also use the Marshal class on VB.NET Structures:

Example:

Public Structure MyStruct
	Dim x as Integer
	Dim y as Integer
End Structure

Dim structure1 as MyStruct
structure1.x = 1
structure1.y = 2

Dim pointer = Marshal.AllocHGlobal(Marshal.SizeOf(structure1))
Marshal.StructureToPtr(structure1, pointer, True)

Dim structure2 as MyStruct = Marshal.PtrToStructure(pointer, New MyStruct().GetType)

Objects are handled differently, because of their Garbage Handling requirements (they are Managed Types). You can use a GCHandle to read and write objects.

Example:

Public Class MyClass
	Public Name As String
	Public Age as Integer
End Class

Dim handle as GCHandle
Dim person as MyClass
person.Name = "Matthew Abbott"
person.Age = 24

handle = GCHandle.Alloc(person)

Example:

Dim person2 as MyClass = handle.Target
handle.Free()

You should check out the System.Runtime.InteropServices namespace on MSDN and see what you can come up with.

Hope that helps.

Adapted from: DotNetBips.com

  • 0

The WINAPI functionality is accessed in a similar way to the C# alternative. This is known as P/Invoke (Platform Invoke), which allows managed code to invoke unmanaged code residing in libraries on the Host computer.

In VB.NET, to declare a WINAPI function, you do the following (e.g. CopyMemory):

Public Static Class WINAPI
	Declare Static Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (ByVal pDst As IntPtr, ByVal pSrc As String, ByVal length As Long)
End Class

In the above example, I have declared a static class, so we can access our WINAPI functions from a single location, without instantiation, ie., you would call WINAPI.CopyMemory(...).

You should look into P/Invoke for more information on using external unmanaged code from .NET.

Also, check out http://www.pinvoke.net for more information.

  • 0

Does this code works for two different applications? I mean if I alloc one object in the first application, pass the memory address to the other, is the other able to start another object (same instance) pointing to the same object. Can we use the same object in different applications? If not what would be the best way to do so? Thank you very much in advance, it's been a long time I'm trying to make it work, thanks again.

This topic is now closed to further replies.
  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Posts

    • Rubbish. It's chock-full of ads and with manifest 3.0,the gloves are off. Google does not even pretend now. They want évil and want your data
    • Glary Utilities 6.27.0.31 by Razvan Serea Glary Utilities offers numerous powerful and easy-to-use system tools and utilities to fix, speed up, maintain and protect your PC. Glary Utilities allow you to clean common system junk files, as well as invalid registry entries and Internet traces. You can manage and delete browser add-ons, analyze disk space usage and find duplicate files. You can also view and manage installed shell extensions, encrypt your files from unauthorized access and use, split large files into smaller manageable files and then rejoin them. Furthermore, Glary Utilities includes the options to find, fix, or remove broken Windows shortcuts, manage the programs that start at Windows startup and uninstall software. All Glary Utilities tools can be accessed through an eye-pleasing and totally simplistic interface. Glary Utilities 6.27.0.31 changelog: Optimized Disk Cleaner: Optimized the scanning algorithm for Firefox to enhance user experience. Optimized Disk Cleaner: Added support for Nitro Pro 14. Optimized Tracks Eraser: Optimized the scanning algorithm for Firefox to enhance user experience. Optimized Tracks Eraser: Added support for Nitro Pro 14. Optimized Startup Manager: Optimized the review algorithm to enhance user experience. Optimized Uninstaller Manager: Optimized the scanning algorithm to enhance user experience. Minor GUI improvements. Minor bug fixes. Download: Glary Utilities 6.27.0.31 | 27.0 MB (Freeware) Download: Portable Glary Utilities | 32.3 MB View: Glary Utilities Homepage | Screenshot Get alerted to all of our Software updates on Twitter at @NeowinSoftware
    • Next shut down Firefox itself and bring it back a year or two later with Chromium. 🫨
    • Microsoft made it very clear : they are not able to create a simple/user-friendly/to the point start-menu. I suggest that they have a look at START 11 made by Stardock
  • Recent Achievements

    • One Month Later
      CoolRaoul earned a badge
      One Month Later
    • First Post
      Kurotama earned a badge
      First Post
    • Collaborator
      Carltonbar earned a badge
      Collaborator
    • Explorer
      MusicLover2112 went up a rank
      Explorer
    • Dedicated
      MadMung0 earned a badge
      Dedicated
  • Popular Contributors

    1. 1
      +primortal
      508
    2. 2
      ATLien_0
      269
    3. 3
      +FloatingFatMan
      243
    4. 4
      +Edouard
      201
    5. 5
      snowy owl
      168
  • Tell a friend

    Love Neowin? Tell a friend!