如何獲得CPU使用率

資料來源:CSDN NT/2000方法：

#include < windows.h >
#include < conio.h >
#include < stdio.h >    #define SystemBasicInformation       0
#define SystemPerformanceInformation 2
#define SystemTimeInformation        3    #define Li2Double(x) ((double)((x).HighPart) * 4.294967296E9   (double)((x).LowPart))    typedef struct
{
    DWORD   dwUnknown1;
    ULONG   uKeMaximumIncrement;
    ULONG   uPageSize;
    ULONG   uMmNumberOfPhysicalPages;
    ULONG   uMmLowestPhysicalPage;
    ULONG   uMmHighestPhysicalPage;
    ULONG   uAllocationGranularity;
    PVOID   pLowestUserAddress;
    PVOID   pMmHighestUserAddress;
    ULONG   uKeActiveProcessors;
    BYTE    bKeNumberProcessors;
    BYTE    bUnknown2;
    WORD    wUnknown3;
} SYSTEM_BASIC_INFORMATION;    typedef struct
{
    LARGE_INTEGER   liIdleTime;
    DWORD           dwSpare[76];
} SYSTEM_PERFORMANCE_INFORMATION;    typedef struct
{
    LARGE_INTEGER liKeBootTime;
    LARGE_INTEGER liKeSystemTime;
    LARGE_INTEGER liExpTimeZoneBias;
    ULONG         uCurrentTimeZoneId;
    DWORD         dwReserved;
} SYSTEM_TIME_INFORMATION;    // ntdll!NtQuerySystemInformation (NT specific!)
//
// The function copies the system information of the
// specified type into a buffer
//
// NTSYSAPI
// NTSTATUS
// NTAPI
// NtQuerySystemInformation(
//    IN UINT SystemInformationClass,    // information type
//    OUT PVOID SystemInformation,       // pointer to buffer
//    IN ULONG SystemInformationLength,  // buffer size in bytes
//    OUT PULONG ReturnLength OPTIONAL   // pointer to a 32-bit
//                                       // variable that receives
//                                       // the number of bytes
//                                       // written to the buffer 
// );
typedef LONG (WINAPI *PROCNTQSI)(UINT,PVOID,ULONG,PULONG);    PROCNTQSI NtQuerySystemInformation;    void main(void)
{
    SYSTEM_PERFORMANCE_INFORMATION SysPerfInfo;
    SYSTEM_TIME_INFORMATION        SysTimeInfo;
    SYSTEM_BASIC_INFORMATION       SysBaseInfo;
    double                         dbIdleTime;
    double                         dbSystemTime;
    LONG                           status;
    LARGE_INTEGER                  liOldIdleTime = {0,0};
    LARGE_INTEGER                  liOldSystemTime = {0,0};        NtQuerySystemInformation = (PROCNTQSI)GetProcAddress(
                                          GetModuleHandle("ntdll"),
                                         "NtQuerySystemInformation"
                                         );        if (!NtQuerySystemInformation)
        return;        // get number of processors in the system
    status = NtQuerySystemInformation(SystemBasicInformation,&SysBaseInfo,sizeof(SysBaseInfo),NULL);
    if (status != NO_ERROR)
        return;
    
printf("\nCPU Usage (press any key to exit):    ");
    while(!_kbhit())
    {
        // get new system time
    status = NtQuerySystemInformation(SystemTimeInformation,&SysTimeInfo,sizeof(SysTimeInfo),0);
        if (status!=NO_ERROR)
            return;            // get new CPU's idle time
        status = NtQuerySystemInformation(SystemPerformanceInformation,&SysPerfInfo,sizeof(SysPerfInfo),NULL);
        if (status != NO_ERROR)
            return;            // if it's a first call - skip it
       if (liOldIdleTime.QuadPart != 0)
       {
            // CurrentValue = NewValue - OldValue
            dbIdleTime = Li2Double(SysPerfInfo.liIdleTime) - Li2Double(liOldIdleTime);
            dbSystemTime = Li2Double(SysTimeInfo.liKeSystemTime) - Li2Double(liOldSystemTime);                // CurrentCpuIdle = IdleTime / SystemTime
            dbIdleTime = dbIdleTime / dbSystemTime;                // CurrentCpuUsage% = 100 - (CurrentCpuIdle * 100) / NumberOfProcessors
            dbIdleTime = 100.0 - dbIdleTime * 100.0 / (double)SysBaseInfo.bKeNumberProcessors   0.5;                printf("\b\b\b\b=%%",(UINT)dbIdleTime);
       }            // store new CPU's idle and system time
        liOldIdleTime = SysPerfInfo.liIdleTime;
        liOldSystemTime = SysTimeInfo.liKeSystemTime;            // wait one second
        Sleep(1000);
    }
    printf("\n");
}    //-------------------------------------------------------------

Windows 9X:

#include < windows.h >
#include < conio.h >
#include < stdio.h >    void main(void)
{
    HKEY hkey;
    DWORD dwDataSize;
    DWORD dwType;
    DWORD dwCpuUsage;        // starting the counter
    if ( RegOpenKeyEx( HKEY_DYN_DATA,
                       "PerfStats\\StartStat",
                       0,KEY_ALL_ACCESS,
                       &hkey ) != ERROR_SUCCESS)
       return;        dwDataSize=sizeof(DWORD);
    RegQueryValueEx( hkey,
                     "KERNEL\\CPUUsage",
                     NULL,&dwType,
                     (LPBYTE)&dwCpuUsage,
                     &dwDataSize );        RegCloseKey(hkey);
    
    // geting current counter's value
    if ( RegOpenKeyEx( HKEY_DYN_DATA,
                       "PerfStats\\StatData",
                       0,KEY_READ,
                       &hkey ) != ERROR_SUCCESS)
       return;        printf("\nCPU Usage (press any key to exit):    ");
    while(!_kbhit())
    {
        dwDataSize=sizeof(DWORD);
        RegQueryValueEx( hkey,
                         "KERNEL\\CPUUsage",
                         NULL,&dwType,
                         (LPBYTE)&dwCpuUsage,
                         &dwDataSize );
        Sleep(500);
        printf("\b\b\b\b=%%",dwCpuUsage);
    }
    printf("\n");        RegCloseKey(hkey);
    
    // stoping the counter
    if ( RegOpenKeyEx( HKEY_DYN_DATA,
                       "PerfStats\\StopStat",
                       0,KEY_ALL_ACCESS,
                       &hkey ) != ERROR_SUCCESS)
       return;        dwDataSize=sizeof(DWORD);
    RegQueryValueEx( hkey,
                     "KERNEL\\CPUUsage",
                     NULL,&dwType,
                     (LPBYTE)&dwCpuUsage,
                     &dwDataSize );        RegCloseKey(hkey);
}

網路志工聯盟----Visita網站http://www.vista.org.tw ---[ 發問前請先找找舊文章 ]--- 發表人 - axsoft 於 2003/02/25 18:38:07

請問程式compile時出現了"[C Error] Unit1.cpp(106): E2268 Call to undefined function '_kbhit'"的錯誤訊息,到底哪裡錯誤了? 我把while(!_kbhit())改成while(!kbhit()),雖然沒有錯誤訊息,但是run時也是會出錯,請問程式有哪裡少了嗎? 謝謝.

_kbhit() 定義在 conio.h .......如果有include 應該是可以用 在win2000 用devc 編譯無誤.......但是用工作管理員看到的結果 並不是一樣....有時候會差到5%以上............也許直接抓工作管理員上面 的數值會正確點...^^ 但不知道怎麼抓 ...

我試著將程式改成在Label上顯示CPU Usage,但出現以下錯誤: 程式碼如下:

//---------------------------------------------------------------------------    //#include 
#pragma hdrstop    #include "Unit1.h"    #include 
#include 
#include     #define SystemBasicInformation       0
#define SystemPerformanceInformation 2
#define SystemTimeInformation        3    #define Li2Double(x) ((double)((x).HighPart) * 4.294967296E9 + (double)((x).LowPart))    typedef struct
{
    DWORD   dwUnknown1;
    ULONG   uKeMaximumIncrement;
    ULONG   uPageSize;
    ULONG   uMmNumberOfPhysicalPages;
    ULONG   uMmLowestPhysicalPage;
    ULONG   uMmHighestPhysicalPage;
    ULONG   uAllocationGranularity;
    PVOID   pLowestUserAddress;
    PVOID   pMmHighestUserAddress;
    ULONG   uKeActiveProcessors;
    BYTE    bKeNumberProcessors;
    BYTE    bUnknown2;
    WORD    wUnknown3;
} SYSTEM_BASIC_INFORMATION;    typedef struct
{
    LARGE_INTEGER   liIdleTime;
    DWORD           dwSpare[76];
} SYSTEM_PERFORMANCE_INFORMATION;    typedef struct
{
    LARGE_INTEGER liKeBootTime;
    LARGE_INTEGER liKeSystemTime;
    LARGE_INTEGER liExpTimeZoneBias;
    ULONG         uCurrentTimeZoneId;
    DWORD         dwReserved;
} SYSTEM_TIME_INFORMATION;    // ntdll!NtQuerySystemInformation (NT specific!)
//
// The function copies the system information of the
// specified type into a buffer
//
// NTSYSAPI
// NTSTATUS
// NTAPI
// NtQuerySystemInformation(
//    IN UINT SystemInformationClass,    // information type
//    OUT PVOID SystemInformation,       // pointer to buffer
//    IN ULONG SystemInformationLength,  // buffer size in bytes
//    OUT PULONG ReturnLength OPTIONAL   // pointer to a 32-bit
//                                       // variable that receives
//                                       // the number of bytes
//                                       // written to the buffer 
// );
typedef LONG (WINAPI *PROCNTQSI)(UINT,PVOID,ULONG,PULONG);    PROCNTQSI NtQuerySystemInformation;    //---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
  : TForm(Owner)
{
}
//---------------------------------------------------------------------------    void __fastcall TForm1::Timer1Timer(TObject *Sender)
{
    SYSTEM_PERFORMANCE_INFORMATION SysPerfInfo;
    SYSTEM_TIME_INFORMATION        SysTimeInfo;
    SYSTEM_BASIC_INFORMATION       SysBaseInfo;
    double                         dbIdleTime;
    double                         dbSystemTime;
    LONG                           status;
    LARGE_INTEGER                  liOldIdleTime = {0,0};
    LARGE_INTEGER                  liOldSystemTime = {0,0};        NtQuerySystemInformation = (PROCNTQSI)GetProcAddress(
                                          GetModuleHandle("ntdll"),
                                         "NtQuerySystemInformation"
                                         );        if (!NtQuerySystemInformation)
        return;        // get number of processors in the system
    status = NtQuerySystemInformation(SystemBasicInformation,&SysBaseInfo,sizeof(SysBaseInfo),NULL);
    if (status != NO_ERROR)
        return;
   while(!kbhit())
   {
    // get new system time
    status = NtQuerySystemInformation(SystemTimeInformation,&SysTimeInfo,sizeof(SysTimeInfo),0);
        if (status!=NO_ERROR)
            return;            // get new CPU's idle time
        status = NtQuerySystemInformation(SystemPerformanceInformation,&SysPerfInfo,sizeof(SysPerfInfo),NULL);
        if (status != NO_ERROR)
            return;            // if it's a first call - skip it
       if (liOldIdleTime.QuadPart != 0)
       {
            // CurrentValue = NewValue - OldValue
            dbIdleTime = Li2Double(SysPerfInfo.liIdleTime) - Li2Double(liOldIdleTime);
            dbSystemTime = Li2Double(SysTimeInfo.liKeSystemTime) - Li2Double(liOldSystemTime);                // CurrentCpuIdle = IdleTime / SystemTime
            dbIdleTime = dbIdleTime / dbSystemTime;                // CurrentCpuUsage% = 100 - (CurrentCpuIdle * 100) / NumberOfProcessors
            dbIdleTime = 100.0 - dbIdleTime * 100.0 / (double)SysBaseInfo.bKeNumberProcessors + 0.5;                //printf("\b\b\b\b%3d%%",(UINT)dbIdleTime);
            Label1->Caption=(UINT)dbIdleTime;
       }            // store new CPU's idle and system time
        liOldIdleTime = SysPerfInfo.liIdleTime;
        liOldSystemTime = SysTimeInfo.liKeSystemTime;
    }
}

請問我該怎麼修改才正確? 謝謝.

BCB的help對kbhit()有這樣的一個描述： Do not use this function in Win32 GUI applications 顯然在視窗介面的程式執行這個函式是有問題的 這個函式的功能在檢查是否有按下任何按鍵... 因此在視窗介面的程式下，你可以另外設定一個旗標來替代 程式初始時旗標設定為false 當form的keydown事件啟動後，旗標改成true 如此就會離開該迴圈了 再換個想法，while迴圈內的程式本來就是要不斷的執行 其實Timer元件的用途也是如此，所以你在Timer元件的event事件中 其實可以去掉while這個功能了..