Получить sizeof

sizeof(_asm_ret)

как мне перевести это в C#?

bool BlockAPI_mono(HANDLE hProcess, char* api_name)
{
    CHAR _asm_ret[] = { 0xC3 };
    char* mono_patch = GetModulePatchByName(hProcess, "mono.dll");
    if (mono_patch == NULL)
        return false;
    HMODULE mono_lib = LoadLibraryA(mono_patch);
    if (mono_lib == NULL)
        return false;
    FARPROC func = GetProcAddress(mono_lib, api_name);
    if (func == NULL)
        return false;
    DWORD dwOldProtect = 0;
    VirtualProtectEx(hProcess, reinterpret_cast<LPVOID>(func), sizeof(_asm_ret), PAGE_EXECUTE_READWRITE, &dwOldProtect);
    bool write = WriteProcessMemory(hProcess, reinterpret_cast<LPVOID>(func), reinterpret_cast<LPCVOID>(_asm_ret), sizeof(_asm_ret), 0);
    VirtualProtectEx(hProcess, reinterpret_cast<LPVOID>(func), sizeof(_asm_ret), dwOldProtect, &dwOldProtect);
    return write;
}