C#•3y ago

Marshal class

So, why i cant read 8 bytes from unmanaged memory? Base address is 40000x16 and 4194304x10, not null

38 Replies

Buddy•3y ago

It doesnt work like that What are you trying to make?

Hanami•3y ago

I'm trying to read the data of another program from RAM and cram it into my program for future use

Hanami•3y ago

Actually here they are

Akseli•3y ago

because you need read access to the processes memory

Hanami•3y ago

and how do I get it?

Akseli•3y ago

if you are on windows, you can use winapi functions to do it

Hanami•3y ago

I know, moreover, I already have such a solution. But I thought it was possible to use the functionality of this class. Anyway thanks for the answer

Buddy•3y ago

what's the program that you want to read from?

Hanami•3y ago

Anno 1404, game

Unknown User•3y ago

Message Not Public

er🎃•3y ago

i do a lot with memory, maybe i can help what problem are you running into exactly? what do 40000x16 and 4194304x10 mean? base 16 and base 10? what the others said is correct, you must p/invoke win32api and do the read from there. Marshal is for managed memory within your own process

Hanami•3y ago

That is, the Marshal class cannot read data from third-party processes?

er🎃•3y ago

that's correct for inter-process (memory) reads, you must invoke kernel functions on all OSes

Hanami•3y ago

Okay, thanks a lot for the answer, now everything falls into place

er🎃•3y ago

[DllImport("kernel32")]
static extern unsafe int ReadProcessMemory(
  IntPtr hProcess,
  IntPtr lpBaseAddress,
  void* lpBuffer,
  UIntPtr nSize,
  UIntPtr* lpNumberOfBytesRead);

[DllImport("kernel32")]
static extern unsafe int ReadProcessMemory(
  IntPtr hProcess,
  IntPtr lpBaseAddress,
  void* lpBuffer,
  UIntPtr nSize,
  UIntPtr* lpNumberOfBytesRead);

i highly implore you upgrade to a .NET 7 preview which has much better library imports on previous versions you'll lose speed marshalling data the above can also be written as this in .net 6 and lower

[DllImport("kernel32")]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool ReadProcessMemory(
  IntPtr hProcess,
  IntPtr lpBaseAddress,
  [MarshalAs(UnmanagedType.LPArray)] byte[] lpBuffer,
  UIntPtr nSize,
  out UIntPtr lpNumberOfBytesRead);

[DllImport("kernel32")]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool ReadProcessMemory(
  IntPtr hProcess,
  IntPtr lpBaseAddress,
  [MarshalAs(UnmanagedType.LPArray)] byte[] lpBuffer,
  UIntPtr nSize,
  out UIntPtr lpNumberOfBytesRead);

but again, this is gonna cost you over the above for .NET 7, you can just do that, and it'll translate that into native calls with source generation for you

Jester•3y ago

wdym you dont need net7 for this

er🎃•3y ago

yeah. that's why i said that's how you can also write it in .net 6 and lower

Jester•3y ago

i miss read Prayge

er🎃•3y ago

[LibraryImport("kernel32")]
[return: MarshalAs(UnmanagedType.Bool)]
static partial unsafe bool ReadProcessMemory(
  nint hProcess,
  nint lpBaseAddress,
  void* lpBuffer,
  nuint nSize,
  out nuint lpNumberOfBytesRead);

[LibraryImport("kernel32")]
[return: MarshalAs(UnmanagedType.Bool)]
static partial unsafe bool ReadProcessMemory(
  nint hProcess,
  nint lpBaseAddress,
  void* lpBuffer,
  nuint nSize,
  out nuint lpNumberOfBytesRead);

this is how i declare it in .net 7

Jester•3y ago

isnt this breaking a TOS though? in that case this should be removed

er🎃•3y ago

not necessarily?

Unknown User•3y ago

Message Not Public

er🎃•3y ago

unless someone can dig up some TOS of Anno 1440 that says no memory reading lol

Jester•3y ago

looks quite likely

er🎃•3y ago

i highly doubt it

Jester•3y ago

games just allow you to do that? Thinkies

er🎃•3y ago

why not?

Jester•3y ago

because you can get an advantage over other players???

er🎃•3y ago

it's a single player game from 2009...

Jester•3y ago

doesnt matter

er🎃•3y ago

yes, it literally does matter

Unknown User•3y ago

Message Not Public

Hanami•3y ago

Guys, I've already used this method to read memory and there were no problems with it, so there's no need to argue🙃

Jester•3y ago

the mods decide i dont

er🎃•3y ago

there's nothing to argue what you're doing cannot work it's impossible Marshal does not do that

Hanami•3y ago

I'm not talking about Marshal, but about this

er🎃•3y ago

so why'd you try it with Marshal? just to see if it would work?

Hanami•3y ago

Yes )

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Marshal class