C++ return float - c++

Question

I create a API for a Game.
My Problem: I want to read a float value from the Memory.
Result (Cheat Engine) 100
My Result with the API: 0.00000
extern "C" __declspec(dllexport) float samp_health()
{
hwnd = FindWindow(NULL, L"MyGame");
GetWindowThreadProcessId(hwnd, &pid);
HANDLE phandle = OpenProcess(PROCESS_VM_READ, false, pid);
float value = 0;
ReadProcessMemory(phandle, (float*)(PlayerPointer + HealthOffset), &value, 4, NULL);
CloseHandle(phandle);
return value;
}
What is wrong?

Answer 1

With this line,
HANDLE phandle = OpenProcess(PROCESS_VM_READ, false, pid);
you need to check for failure.
And in this following line,
ReadProcessMemory(phandle, (float*)(PlayerPointer + HealthOffset), &value, 4, NULL);
assuming the ReadProcessMemory works as roughly indicated by the arguments, the PlayerPointer needs to be a valid pointer in the process identified by phandle, and if the HealthOffset is an offset in bytes, then PlayerPointer needs to be a pointer to byte.
Most likely it's not.
Reading process memory is generally not a good way to communicate between processes.
Here are some alternatives:
Don't do process communication, do threads or whatever.
Use Windows COM technology.
Use Windows mailslots.
Use Windows window messages (e.g. WM_DATA).
Use sockets.
Use files.
Use pipes.
Almost anything, just not the direct access of process memory.
Summing up, the main problem is use of a too low level of abstraction.