How to use the string as a function as function call?

Karthik Agarwal

14y2.2k

Hi,

I have a string which i will be getting from the input from a user.
But i should take the input what user gives and obviously that is the name of a function in my code. So i should call the function which the user has entered. How can i do this?

Example: Suppose the user has entered a name "interpolation" in the textbox in the form and then he presses enter. Then i should read the name as follws:

String ^ function_call = textbox->Text;
and after this operation i should call the function interpolation which user has entered.
int index = interpolation();//this is what i need this function will return a integer.

3 Replies

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Vulpes14y ago
Accepted answer
OK, here's an example of how you can call a global function using reflection:

#include "stdafx.h"

using namespace System;
using namespace System::Reflection;

int interpolation()
{
return 42;
}

int main(array ^args)
{
String^ functionName = "interpolation";
Module^ module = Assembly::GetExecutingAssembly()->GetModules(false)[0];
BindingFlags bf = BindingFlags::Static | BindingFlags::NonPublic;
CallingConventions cc = CallingConventions::Standard;
array^ types = {};
MethodInfo^ mi = module->GetMethod(functionName, bf, nullptr, cc, types, nullptr);

if (mi == nullptr)
{
Console::WriteLine("A global function called '{0}' does not exist", functionName);
}
else
{
Object^ result = mi->Invoke(nullptr, nullptr);
int index = *reinterpret_cast(result);
Console::WriteLine("index is {0}", index);
}
Console::ReadKey();
return 0;
}
Karthik Agarwal14y ago
The function is global function.

I don't wanna do it in if else ladder and i want to do it probably in some other way.
Vulpes14y ago
Well, the only way to make such calls 'early bound' is to use an if/else if/else ladder:

if (function_call == "interpolation")
{
int index = interpolation();
// do something with index
}
else if () // etc

Otherwise, you'd need to use reflection to make 'late bound' calls.

Is the function you're calling an instance or static method of some class or struct or is it a global function of the current assembly?