C++ - DLL 注入器中未解析的外部

我真的看不出我收到此错误的原因，我已经看了一下，显然这与定义一个什么都不做的函数有关？不幸的是，我真的无法说出这里的问题是什么，所以任何帮助将不胜感激。

这是我的源代码：

主.cpp

#include <Windows.h> 
#include <tlhelp32.h> 
#include <shlwapi.h> 
#include <conio.h> 
#include <stdio.h> 
#include <iostream>
using namespace std;
#define WIN32_LEAN_AND_MEAN 
#define CREATE_THREAD_ACCESS (PROCESS_CREATE_THREAD |    PROCESS_QUERY_INFORMATION | PROCESS_VM_OPERATION | PROCESS_VM_WRITE |    PROCESS_VM_READ) 
BOOL Inject(DWORD pID, const char * DLL_NAME); 
DWORD GetTargetThreadIDFromProcName(const char * ProcName); 
using namespace std;
char buf[MAX_PATH];
LPVOID RemoteString, LoadLib;
HANDLE Proc;
DWORD pID;
__int32 main() 
{
   pID = GetTargetThreadIDFromProcName("Program.exe"); 
   buf[MAX_PATH] = {0}; 
   GetFullPathName("DLL.dll", MAX_PATH, buf, NULL);
   if(!Inject(pID, buf)) cout << ("Failed to inject!nnn");
   system("pause");
   return 0; 
} 
BOOL Inject(DWORD pID, const char * DLL_NAME) 
{  
   char buf[50] = {0}; 
   if(!pID) return false; 
   Proc = OpenProcess(PROCESS_ALL_ACCESS, FALSE, pID); 
   if(!Proc) return false; 
   LoadLib = (LPVOID)GetProcAddress(GetModuleHandle("kernel32.dll"), "LoadLibraryA"); 
   RemoteString = (LPVOID)VirtualAllocEx(Proc, NULL, strlen(DLL_NAME), MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE); 
   WriteProcessMemory(Proc, (LPVOID)RemoteString, DLL_NAME, strlen(DLL_NAME),    NULL); 
   CreateRemoteThread(Proc, NULL, NULL, (LPTHREAD_START_ROUTINE)LoadLib,    (LPVOID)RemoteString, NULL, NULL); 
   CloseHandle(Proc); 
   return true; 
} 
DWORD GetTargetThreadIDFromProcName(const char * ProcName) 
{ 
   PROCESSENTRY32 pe; 
   HANDLE thSnapShot; 
   BOOL retval, ProcFound = false; 
   thSnapShot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0); 
   if(thSnapShot == INVALID_HANDLE_VALUE) return false; 
   pe.dwSize = sizeof(PROCESSENTRY32); 
   retval = Process32First(thSnapShot, &pe); 
   while(retval) 
   { 
      if(StrStrI(pe.szExeFile, ProcName)) return pe.th32ProcessID; 
      retval = Process32Next(thSnapShot, &pe); 
   } 
   return 0; 
}

我得到的错误如下：

main.obj

unresolved external symbol __imp__StrStrIA@8 referenced in function "unsigned long __cdecl GetTargetThreadIDFromProcName(char const *)" (?GetTargetThreadIDFromProcName@@YAKPBD@Z)

喷油器.exe

1 unresolved externals

任何解决方案或只是一些有助于理解为什么会发生这种情况的帮助都会很棒！