C/C++获取Windows的CPU、内存、硬盘使用率

//Win 内存 使用率  
DWORD getWin_MemUsage()
{
	MEMORYSTATUS ms;
	::GlobalMemoryStatus(&ms);
	return ms.dwMemoryLoad;
}

__int64 CompareFileTime(FILETIME time1, FILETIME time2)
{
	__int64 a = time1.dwHighDateTime << 32 | time1.dwLowDateTime;
	__int64 b = time2.dwHighDateTime << 32 | time2.dwLowDateTime;

	return (b - a);
}

//Win CPU使用情况
void getWin_CpuUsage()
{
	HANDLE hEvent;
	BOOL res;
	FILETIME preidleTime;
	FILETIME prekernelTime;
	FILETIME preuserTime;
	FILETIME idleTime;
	FILETIME kernelTime;
	FILETIME userTime;

	res = GetSystemTimes(&idleTime, &kernelTime, &userTime);
	preidleTime = idleTime;
	prekernelTime = kernelTime;
	preuserTime = userTime;

	hEvent = CreateEventA(NULL, FALSE, FALSE, NULL); // 初始值为 nonsignaled ，并且每次触发后自动设置为nonsignaled

	while (true)
	{
		WaitForSingleObject(hEvent, 1000);
		res = GetSystemTimes(&idleTime, &kernelTime, &userTime);

		__int64 idle = CompareFileTime(preidleTime, idleTime);
		__int64 kernel = CompareFileTime(prekernelTime, kernelTime);
		__int64 user = CompareFileTime(preuserTime, userTime);

		__int64 cpu = (kernel + user - idle) * 100 / (kernel + user);
		__int64 cpuidle = (idle)* 100 / (kernel + user);
		//cout << "CPU利用率:" << cpu << "%" << " CPU空闲率:" << cpuidle << "%" << endl;

		preidleTime = idleTime;
		prekernelTime = kernelTime;
		preuserTime = userTime;
	}
}

//获取 WIN 硬盘使用情况  
int getWin_DiskUsage()
{
    int DiskCount = 0;
    DWORD DiskInfo = GetLogicalDrives();
    //利用GetLogicalDrives()函数可以获取系统中逻辑驱动器的数量，函数返回的是一个32位无符号整型数据。
    while (DiskInfo)//通过循环操作查看每一位数据是否为1，如果为1则磁盘为真,如果为0则磁盘不存在。
    {
        if (DiskInfo & 1)//通过位运算的逻辑与操作，判断是否为1
        {
            ++DiskCount;
        }
        DiskInfo = DiskInfo >> 1;//通过位运算的右移操作保证每循环一次所检查的位置向右移动一位。
        //DiskInfo = DiskInfo/2;
    }
    cout << "Logical Disk Number:" << DiskCount << endl;
    //-----------------------------------------------------------------------------------------
    int DSLength = GetLogicalDriveStrings(0, NULL);
    //通过GetLogicalDriveStrings()函数获取所有驱动器字符串信息长度。
    char* DStr = new char[DSLength];//用获取的长度在堆区创建一个c风格的字符串数组
    GetLogicalDriveStrings(DSLength, (LPTSTR)DStr);
    //通过GetLogicalDriveStrings将字符串信息复制到堆区数组中,其中保存了所有驱动器的信息。
  
    int DType;
    int si = 0;
    BOOL fResult;
    unsigned _int64 i64FreeBytesToCaller;
    unsigned _int64 i64TotalBytes;
    unsigned _int64 i64FreeBytes;
  
    for (int i = 0; i<DSLength / 4; ++i)//为了显示每个驱动器的状态，则通过循环输出实现，由于DStr内部保存的数据是A:\NULLB:\NULLC:\NULL，这样的信息，所以DSLength/4可以获得具体大循环范围 
    {
        char dir[3] = { DStr[si], '：', '\\' };
        cout << dir;
        DType = GetDriveType(DStr + i * 4);
        //GetDriveType函数，可以获取驱动器类型，参数为驱动器的根目录
        if (DType == DRIVE_FIXED)
        {
            cout << "Hard Disk";
        }
        else if (DType == DRIVE_CDROM)
        {
            cout << "CD-ROM";
        }
        else if (DType == DRIVE_REMOVABLE)
        {
            cout << "Removable Disk";
        }
        else if (DType == DRIVE_REMOTE)
        {
            cout << "Network Disk";
        }
        else if (DType == DRIVE_RAMDISK)
        {
            cout << "Virtual RAM Disk";
        }
        else if (DType == DRIVE_UNKNOWN)
        {
            cout << "Unknown Device";
        }

        fResult = GetDiskFreeSpaceEx(
            dir,
            (PULARGE_INTEGER)&i64FreeBytesToCaller,
            (PULARGE_INTEGER)&i64TotalBytes,
            (PULARGE_INTEGER)&i64FreeBytes);
        //GetDiskFreeSpaceEx函数，可以获取驱动器磁盘的空间状态,函数返回的是个BOOL类型数据
        if (fResult)//通过返回的BOOL数据判断驱动器是否在工作状态
        {
            cout << " totalspace:" << (float)i64TotalBytes / 1024 / 1024 << " MB";//磁盘总容量
            cout << " freespace:" << (float)i64FreeBytesToCaller / 1024 / 1024 << " MB";//磁盘剩余空间
        }
        else
        {
            cout << " 设备未准备好";
        }
        cout << endl;
        si += 4;
    }
    return 0;
}

int main( int argc, char **argv )
{
    //+++======================获取windows 内存使用率==================+++//
    DWORD dwValue = getWin_MemUsage();
    printf("内存使用率为 %d %% \n",dwValue);
    //+++======================获取Windows CPU使用率====================+++//
    //getWin_CpuUsage();
    //+++======================获取Windows 硬盘使用====================+++//
    getWin_DiskUsage();
        return 0;
}