我怎么能初始化 LPVOID

Question

I have a function which should return me text. This is the declaration:

typedef bool(WINAPI* GetMenuHelpName)(intptr_t dll, LPVOID lpBuffer, int size);

I suppose my text is in LpBuffer :

GetMenuHelpName func2 = (GetMenuHelpName)GetProcAddress(hGetProcIDDLL, "GetMenuHelpName");
LPVOID lpBuffer;
func2(instance, lpBuffer, 2048);

I got this error:

Error C4700 : uninitialized local variable 'lpBuffer' used

How could I initialize lpBuffer and put my result in a std:string ?

Answer 1

An LPVOID type is exactly the same as void* , which means a pointer to something which doesn't have a specific type. Also, as it stands right now, lpBuffer isn't pointing at anything because it has not been initialized. There are two main ways to initialize this pointer: on the heap or on the stack. To initalize on the stack, initialize it like a char array:

char lpb[1000]; // Or however much space
LPVOID lpBuffer = (LPVOID) lpb;

To initialize on the heap, use the malloc (memory allocation) function. This allocates some space somewhere and returns a pointer to it. Just remember to call free on it when you're done to give that space back to the OS:

#include <stdlib.h> // malloc, free

// ...

LPVOID lpBuffer = malloc(1000); // pick your space

// ...

free(lpBuffer);              // release the space

As for converting to a std::string , see this page .