VS++ 管道进程获取CMD返回值

int ExecDosCmdRet(CString strCmd,CString& strResult)
{
	SECURITY_ATTRIBUTES sa;
	HANDLE hRead,hWrite;
	sa.nLength = sizeof(SECURITY_ATTRIBUTES);
	sa.lpSecurityDescriptor = NULL;
	sa.bInheritHandle = TRUE;
	if (!CreatePipe(&hRead,&hWrite,&sa,0))
	{
		return FALSE;
	}

	STARTUPINFO si;
	PROCESS_INFORMATION pi;
	ZeroMemory(&si,sizeof(STARTUPINFO));

	si.cb = sizeof(STARTUPINFO);
	GetStartupInfo(&si);
	si.hStdError = hWrite; //把创建进程的标准错误输出重定向到管道输入 
	si.hStdOutput = hWrite; //把创建进程的标准输出重定向到管道输入 
	si.wShowWindow = SW_HIDE;
	si.dwFlags = STARTF_USESHOWWINDOW | STARTF_USESTDHANDLES;
	//关键步骤，CreateProcess函数参数意义请查阅MSDN 
	if (!CreateProcess(NULL,strCmd.GetBuffer(),NULL,TRUE,&si,&pi))
	{
		CloseHandle(hWrite);
		CloseHandle(hRead);
		return FALSE;
	}
	CloseHandle(hWrite);

	char buffer[4096] = { 0 }; //用4K的空间来存储输出的内容，只要不是显示文件内容，一般情况下是够用了。 
	DWORD bytesRead;

	while (true)
	{
		if (ReadFile(hRead,buffer,4095,&bytesRead,NULL) == NULL)
			break;
		strResult += buffer;
	}
	CloseHandle(hRead);

	return pi.dwThreadId;
}

int CScanWeakPasswd::ExecDosCmdRet(CString strCmd,sizeof(STARTUPINFO));
	DWORD dwExitCode = 0;

	si.cb = sizeof(STARTUPINFO);
	GetStartupInfo(&si);
	si.hStdError = hWrite; //把创建进程的标准错误输出重定向到管道输入 
	si.hStdOutput = hWrite; //把创建进程的标准输出重定向到管道输入 
	si.wShowWindow = SW_HIDE;
	si.dwFlags = STARTF_USESHOWWINDOW | STARTF_USESTDHANDLES;
	//关键步骤，CreateProcess函数参数意义请查阅MSDN 
	if (!CreateProcess(NULL,&pi))
	{
		CloseHandle(hWrite);
		CloseHandle(hRead);
		return FALSE;
	}

	WaitForSingleObject(pi.hProcess,INFINITE);    这两行不一样
	GetExitCodeProcess(pi.hProcess,&dwExitCode);  这两行不一样，等待进程自身给予的返回值

	CloseHandle(hWrite);

	char buffer[4096] = { 0 }; //用4K的空间来存储输出的内容，只要不是显示文件内容，一般情况下是够用了。 
	DWORD bytesRead;

	while (true)
	{
		if (ReadFile(hRead,NULL) == NULL)
			break;
		strResult = buffer;
	}
	CloseHandle(hRead);

	return dwExitCode;
}