How to Invoke a Method?

[gideon25]

Hi, I noticed that cheatengine mono has a function that invokes a method. Can someone show me a sample script where that is possible using the [URL='https://wiki.cheatengine.org/index.php?title=Mono:Lua:mono_invoke_method&action=edit&redlink=1']mono_invoke_method[/URL] in the

mono LUA_Functions? Like use this method:

DebugMenu_Cheats:FlipMapCards



I need a script example because I want to make some options that invoke various debug cheats. I used the mono dissector but can't figure out how to get it into a script. Thanks!

[Anonymous]

I'd never done it before, but here's a simple example that works with DeadAge. I find the combatant pointer with an AA script and this works to return the current HP, pretty cool...

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local method = mono_findMethod('', 'Combatant', 'GetCurrentHP') -- no namespace



local address = 0x24173e70 -- address of main player I found



local domain = mono_enumDomains()[1] -- should only be one domain, but needed for call



return mono_invoke_method(domain, method, address, {}) -- empty table for args

In a script you would just put "{$lua}" before and "${asm}" after it and the lua code will run when you enable/disable the script, and only run if syntaxcheck isn't true. This little diddy speaks the current hit points out loud when enabled:

Code: Select all

[enable]

{$lua}

if (syntaxcheck) then return end

local method = mono_findMethod('', 'Combatant', 'GetCurrentHP')

local address = readPointer('pCharacter') -- global pointer storing pointer to a 'Combatant' instance

local class = mono_method_getClass(method)

local domain = mono_enumDomains()[1]

local hp = mono_invoke_method(domain, method, address, {})

local name = readString(readPointer(readPointer('pCharacter')+0x18)+0x0c, 32, true)

speak(name..' currently has '..tostring(math.floor(hp))..' hit points')

{$asm}



[disable]

[Anonymous]

Great thanks! I did it like this and it worked:

Code: Select all

[enable]



{$lua}

if (syntaxcheck) then return end

local method = mono_findMethod('', 'DebugMenu_Cheats', 'FlipMapCards')

local class = mono_method_getClass(method)

local domain = mono_enumDomains()[1]

local hp = mono_invoke_method(domain, method, address, {})

{$asm}



[disable]

Now what about methods that want you to set a bool or something? Like I can call these get and set but nothing happens. Take a look at this screenshot from Dnspy please:



It looks like its a method called set_AllTrials but there is a rachet which means its a "member" so maybe Im not coding it correctly? Also it looks like all of the racthets Members have a get and set method and I think they want a value. like set it to 1 to enable? Anyway this doesn't do anything:

Code: Select all

[enable]



{$lua}

if (syntaxcheck) then return end

local method = mono_findMethod('', 'DebugMenu_Cheats', 'set_AllTrials')

local class = mono_method_getClass(method)

local domain = mono_enumDomains()[1]

local hp = mono_invoke_method(domain, method, address, {})

{$asm}



[disable]

And looking at this screenshot when I use cheat engine JIT to invoke it, it wants a bool:





Do I have to add extra commas because its a "member" and how do I set a bool in the script to 1 (just to try)?

Thanks a LOT, this will help me in the future!

[TimFun13]

Looking at the "monoscript.lua" file, it looks like the args is a table with type and value keys/values.

Try the mono_invoke_method_dialog if you are just testing stuff.



CE folder/autorun/monoscript.lua

line 1659

Code: Select all

function mono_invoke_method_dialog(domain, method, address)

  --spawn a dialog where the user can fill in fields like: instance and parameter values

  --parameter fields will be of the proper type

line 1832

Code: Select all

    local params=mono_method_get_parameters(method)



    --use monoTypeToVartypeLookup to convert it to the type mono_method_invole likes it

    local args={}

    for i=1, #params.parameters do

      args[i]={}

      args[i].type=monoTypeToVartypeLookup[params.parameters[i].type]

      if args[i].type==vtString then

        args[i].value=mifinfo.parameters[i].edtVarText.Text

      else

        args[i].value=tonumber(mifinfo.parameters[i].edtVarText.Text)

      end



      if args[i].value==nil then

        messageDialog(translate('parameter ')..i..': "'..mifinfo.parameters[i].edtVarText.Text..'" '..translate('is not a valid value'), mtError, mbOK)

        return

      end

    end

    

    _G.args=args

    _G.instance=instance

    _G.method=method

    _G.bla=123

    

    local r=mono_invoke_method(domain, method, instance, args)

    if r then

      print(r)

    end

line 1891

Code: Select all

function mono_invoke_method(domain, method, object, args)

[gideon25]

Yea I tried using the dialog to test some of them out and I guess some aren't working. But lets say I wanted to put in a boolean value directly into a script without using the dialog. Is that even possible? like what would it look like with this script here:

Code: Select all

[enable]



{$lua}

if (syntaxcheck) then return end

local method = mono_findMethod('', 'DebugMenu_Cheats', 'set_AllTrials')

local class = mono_method_getClass(method)

local domain = mono_enumDomains()[1]

local hp = mono_invoke_method(domain, method, address, {})

{$asm}



[disable]

So I want to set_AllTrials to boolean =1. How would it be written? Also I see Domain, Method,Object,args. Also Set_AllTrials is a "member." Thanks!

[TimFun13]

From what I can tell you just need to set the type and value for each argument; The "set_AllTrials" only has 1 argument so something like this should work.

Code: Select all

[enable]

{$lua}

if (syntaxcheck) then return end

local method = mono_findMethod('', 'DebugMenu_Cheats', 'set_AllTrials')

local class = mono_method_getClass(method)

local domain = mono_enumDomains()[1]

local args = {}

args[1] = {}

args[1].type = monoTypeToVartypeLookup[MONO_TYPE_BOOLEAN] -- vtByte

args[1].value = 1

local r = mono_invoke_method(domain, method, address, args)

if r then

    print(r)

end

{$asm}

[disable]

[koderkrazy]

Thank you guys!

I've successfully called the getter and setter methods on player object after learning from above discussion.

Check my table Hero-U_TableV3 threads/hero-u-rogue-to-redemption-time ... mode.7417/



91 I've managed to call most of the methods on the stat object except one:

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    public Stat GetStat(string name)

    {

        return (Stat)(((object)Skills[name]) ?? ((object)Attributes[name]));

    }

My Lua code:

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[enable]

{$lua}

if (syntaxcheck) then return end

  print('Start!')



  local method = mono_findMethod('', 'CharacterSheet', 'GetStat')

  print(string.format('Method ptr: %02X', method))



  local address = readPointer('pCharSheet')



  local args={}

  args[1] = {}

  args[1].type = monoTypeToVartypeLookup[MONO_TYPE_STRING]

  --args[1].value='Stealth'     

  --args[1].value = getAddress(pSkillName) --utf 16 string  

  args[1].value = getAddress('vStringObject')

  print(string.format('String obj ptr: %02X', args[1].value))



  local r = mono_invoke_method(nil, method, address, args)

  print(r)



  print('Done!')



{$asm}

[disable]



Output Lua Engine Window:

Start! 

Method ptr: 184DB8C8 

String obj ptr: 1B80180 

 

Done! 

I've tried to pass System.String object reference(literals that game uses), vStringObject is the object in above code, but still it's not working.

What am I missing here?



Also, when I start debugging mono features get de-activated. Is there any way to keep them both running?

[TimFun13]

18664

Not really sure but maybe you need to use "MONO_TYPE_CHAR" as it is set to "vtString".

Code: Select all

[enable]

{$lua}

if (syntaxcheck) then return end

  print('Start!')



  local method = mono_findMethod('', 'CharacterSheet', 'GetStat')

  print(string.format('Method ptr: %02X', method))



  local address = readPointer('pCharSheet')



  local args={}

  args[1] = {}

  args[1].type = monoTypeToVartypeLookup[MONO_TYPE_CHAR] -- vtString

  args[1].value='Stealth'

  --print(string.format('String obj ptr: %02X', args[1].value))



  local r = mono_invoke_method(nil, method, address, args)

  print(r)



  print('Done!')



{$asm}

[disable]

[koderkrazy]

MONO_TYPE_CHAR worked.

Thanks!