Ho to call an object method with another object method as argument?

[SamueleD78]

So i have a method in an object

System.Void ForEach(System.Func<Nabe.Internal.File,System.Boolean> func); // 0x02be142c
and i have another method in another object with the same params:

System.Boolean IsExistOnLocal(Nabe.Internal.File file, System.Boolean isStrict); // 0x02fff828

i could get the reference to the methods:

const IsExistOnLocal = inst.method<boolean>("IsExistOnLocal");

const Nabe_Internal_Catalog = new Il2Cpp.Object(inst.method<Il2Cpp.Pointer>("get_Catalog").invoke());
const Nabe_Internal_Catalog_ForEach = Nabe_Internal_Catalog.method("ForEach");

now, how can i call Nabe_Internal_Catalog_ForEach passing IsExistOnLocal as argument?

i've tryed hard without understanding how ^^''
ty so much in advance

[vfsfitvnm]

Well, this is a problematic territory. You should find a way to create a System.Func<Nabe.Internal.File, System.Boolean> object.

This is its constructor:

System.Void .ctor(System.Object object, System.IntPtr method);

object should be the instance the method will be called against, method is a pointer (should be the one you get via handle, not virtualAddress).

You may take a shot at it.

PS - This line

const Nabe_Internal_Catalog = new Il2Cpp.Object(inst.method<Il2Cpp.Pointer>("get_Catalog").invoke());

is "incorrect" (it works anyway because of abstractions), you should do:

// prefer lowerCase for C# objects to avoid confusion with methods/classes
const nabeInternalCatalog = inst.method<Il2Cpp.Object>("get_Catalog").invoke();

[SamueleD78]

Thank you for the suggestions! Yes my bad, too many copy & paste

Mmh i don't understand why i have to create the object.
the IsExistOnLocal it's exactly the function needed, and it already exists in an object.

if it was normal code, i woul probably had called this as:

objA.forEach(objB.IsExistOnLocal);

i've tryed

ForEach.invoke(IsExistOnLocal.handle);

but it gives an access violation

[vfsfitvnm]

Mmh i don't understand why i have to create the object.

You have to because it expects a C# object.

IsExistOnLocal.handle returns a pointer to a Il2Cpp.Method, a native struct, (which is not a System.Reflection.MethodInfo nor a System.Func).

[SamueleD78]

understood, my mistake in messing System.Func with a normal function and not an object. So that would be:

const test = Il2Cpp.Image.corlib.class("System.Func`1").inflate(Il2Cpp.Image.corlib.class("System.Boolean"));

result:

class System.Func<System.Boolean> : System.MulticastDelegate
{
    
    System.Void .ctor(System.Object object, System.IntPtr method); // 0x02ec0a64
    System.Boolean Invoke(); // 0x02d975dc
    System.IAsyncResult BeginInvoke(System.AsyncCallback callback, System.Object object); // 0x02322560
    System.Boolean EndInvoke(System.IAsyncResult result); // 0x0272294c
}

then:

const test2 = test.alloc();
test2.method(".ctor").invoke(inst, IsExistOnLocal.handle);
Internal_Catalog_ForEach.invoke(test2);

But access violation again. What i'm doing wrong?

[vfsfitvnm]

You are obtaining a System.Func<System.Boolean>, but a System.Func<Nabe.Internal.File, System.Boolean> is required:

const SystemBoolean = Il2Cpp.Image.corlib.class("System.Boolean");
const SystemFunc = Il2Cpp.Image.corlib.class("System.Func`2").inflate(/**/, SystemBoolean);

Alternatively, you could just do:

const SystemFunc = nabeInternalCatalog.method("ForEach").parameter("func").type.class;

[SamueleD78]

Ohhhh now i get it!!! Thank you so much!!

Being a Func, the first param is a calling param (T), the last param it's always the returning value.

So actually i needed to search for a boolean func(struct), not for a void func(struct, bool).
I did it following your advices and it's working flawlessly.

Thank you SO much, you really helped me a lot ^^