论坛里关于CPU的占用率回答,请问为什么只能用procedure TForm1.Button1Click(Sender: TObject);(195分)

来自：vine, 时间：2002-9-23 13:44:00, ID：1340925
How to get the CPU usage in percent
const
SystemBasicInformation = 0;
SystemPerformanceInformation = 2;
SystemTimeInformation = 3;

type
TPDWord = ^DWORD;

TSystem_Basic_Information = packed record
dwUnknown1: DWORD;
uKeMaximumIncrement: ULONG;
uPageSize: ULONG;
uMmNumberOfPhysicalPages: ULONG;
uMmLowestPhysicalPage: ULONG;
uMmHighestPhysicalPage: ULONG;
uAllocationGranularity: ULONG;
pLowestUserAddress: Pointer;
pMmHighestUserAddress: Pointer;
uKeActiveProcessors: ULONG;
bKeNumberProcessors: byte;
bUnknown2: byte;
wUnknown3: word;
end;

type
TSystem_Performance_Information = packed record
liIdleTime: LARGE_INTEGER; {LARGE_INTEGER}
dwSpare: array[0..75] of DWORD;
end;

type
TSystem_Time_Information = packed record
liKeBootTime: LARGE_INTEGER;
liKeSystemTime: LARGE_INTEGER;
liExpTimeZoneBias: LARGE_INTEGER;
uCurrentTimeZoneId: ULONG;
dwReserved: DWORD;
end;

var
NtQuerySystemInformation: function(infoClass: DWORD;
buffer: Pointer;
bufSize: DWORD;
returnSize: TPDword): DWORD; stdcall = nil;


liOldIdleTime: LARGE_INTEGER = ();
liOldSystemTime: LARGE_INTEGER = ();

function Li2Double(x: LARGE_INTEGER): Double;
begin
Result := x.HighPart * 4.294967296E9 + x.LowPart
end;

procedure GetCPUUsage;
var
SysBaseInfo: TSystem_Basic_Information;
SysPerfInfo: TSystem_Performance_Information;
SysTimeInfo: TSystem_Time_Information;
status: Longint; {long}
dbSystemTime: Double;
dbIdleTime: Double;

bLoopAborted : boolean;

begin
if @NtQuerySystemInformation = nil then
NtQuerySystemInformation := GetProcAddress(GetModuleHandle('ntdll.dll'),
'NtQuerySystemInformation');

// get number of processors in the system

status := NtQuerySystemInformation(SystemBasicInformation, @SysBaseInfo, SizeOf(SysBaseInfo), nil);
if status <> 0 then Exit;

// Show some information
with SysBaseInfo do
begin
ShowMessage(
Format('uKeMaximumIncrement: %d'#13'uPageSize: %d'#13+
'uMmNumberOfPhysicalPages: %d'+#13+'uMmLowestPhysicalPage: %d'+#13+
'uMmHighestPhysicalPage: %d'+#13+'uAllocationGranularity: %d'#13+
'uKeActiveProcessors: %d'#13'bKeNumberProcessors: %d',
[uKeMaximumIncrement, uPageSize, uMmNumberOfPhysicalPages,
uMmLowestPhysicalPage, uMmHighestPhysicalPage, uAllocationGranularity,
uKeActiveProcessors, bKeNumberProcessors]));
end;


bLoopAborted := False;

while not bLoopAborted do
begin

// get new system time
status := NtQuerySystemInformation(SystemTimeInformation, @SysTimeInfo, SizeOf(SysTimeInfo), 0);
if status <> 0 then Exit;

// get new CPU's idle time
status := NtQuerySystemInformation(SystemPerformanceInformation, @SysPerfInfo, SizeOf(SysPerfInfo), nil);
if status <> 0 then Exit;

// if it's a first call - skip it
if (liOldIdleTime.QuadPart <> 0) then
begin

// 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 / SysBaseInfo.bKeNumberProcessors + 0.5;

// Show Percentage
Form1.Label1.Caption := FormatFloat('CPU Usage: 0.0 %',dbIdleTime);

Application.ProcessMessages;

// Abort if user pressed ESC or Application is terminated
bLoopAborted := (GetKeyState(VK_ESCAPE) and 128 = 128) or Application.Terminated;

end;

// store new CPU's idle and system time
liOldIdleTime := SysPerfInfo.liIdleTime;
liOldSystemTime := SysTimeInfo.liKeSystemTime;

// wait one second
Sleep(1000);
end;
end;


procedure TForm1.Button1Click(Sender: TObject);
begin
GetCPUUsage
end;
你好！我是delphi爱好者,论坛里关于CPU的占用率回答,请问为什么只能用procedure TForm1.Button1Click(Sender: TObject);
begin
GetCPUUsage
end;
而不能用一打开程序就运行: procedure TForm1.FormCreate(Sender: TObject);
begin
GetCPUUsage
end; (无法运行)?
也不能用时钟procedure TForm1.Timer1Timer(Sender: TObject);
begin
GetCPUUsage
end;?(无法运行)
请问如何解决?谢谢!我立刻加分!

gzing

GetCPUUsage
独占主线程的时间太长，用这两种方法都不好，为什么不建一个子线程来GetCPUUsage
?

unit adCpuUsage;

{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
CPU Usage Measurement routines for Delphi and C++ Builder

Author: Alexey A. Dynnikov
EMail: aldyn@chat.ru
WebSite: http://www.aldyn.ru/
Support: Use the e-mail aldyn@chat.ru
or support@aldyn.ru

Creation: Jul 8, 2000
Version: 1.02

Legal issues: Copyright (C) 2000 by Alexey A. Dynnikov <aldyn@chat.ru>

This software is provided 'as-is', without any express or
implied warranty. In no event will the author be held liable
for any damages arising from the use of this software.

Permission is granted to anyone to use this software for any
purpose, including commercial applications, and to alter it
and redistribute it freely, subject to the following
restrictions:

1. The origin of this software must not be misrepresented,
you must not claim that you wrote the original software.
If you use this software in a product, an acknowledgment
in the product documentation would be appreciated but is
not required.

2. Altered source versions must be plainly marked as such, and
must not be misrepresented as being the original software.

3. This notice may not be removed or altered from any source
distribution.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
USAGE:

1. Include this unit into project.

2. Call GetCPUCount to obtain the numbr of processors in the system

3. Each time you need to know the value of CPU usage call the CollectCPUData
to refresh the CPU usage information. Then call the GetCPUUsage to obtain
the CPU usage for given processor. Note that succesive calls of GetCPUUsage
without calling CollectCPUData will return the same CPU usage value.

Example:

procedure TTestForm.TimerTimer(Sender: TObject);
var i: Integer;
begin
CollectCPUData; // Get the data for all processors

for i:=0 to GetCPUCount-1 do // Show data for each processor
MInfo.Lines:=Format('CPU #%d - %5.2f%%',[i,GetCPUUsage(i)*100]);
end;
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}

interface

uses
Windows, SysUtils;

// Call CollectCPUData to refresh information about CPU usage
procedure CollectCPUData;

// Call it to obtain the number of CPU's in the system
function GetCPUCount: Integer;

// Call it to obtain the % of usage for given CPU
function GetCPUUsage(Index: Integer): Double;

// For Win9x only: call it to stop CPU usage monitoring and free system resources
procedure ReleaseCPUData;

implementation

{$ifndef ver110}

{$ifndef ver90}
{$ifndef ver100}
{$define UseInt64}
{$endif}
{$endif}


{$ifdef UseInt64}
type TInt64 = Int64;
{$else}
type TInt64 = Comp;
{$endif}

{$else}

type TInt64 = TLargeInteger;

{$endif}

type
PInt64 = ^TInt64;

type
TPERF_DATA_BLOCK = record
Signature : array[0..4 - 1] of WCHAR;
LittleEndian : DWORD;
Version : DWORD;
Revision : DWORD;
TotalByteLength : DWORD;
HeaderLength : DWORD;
NumObjectTypes : DWORD;
DefaultObject : Longint;
SystemTime : TSystemTime;
Reserved: DWORD;
PerfTime : TInt64;
PerfFreq : TInt64;
PerfTime100nSec : TInt64;
SystemNameLength : DWORD;
SystemNameOffset : DWORD;
end;

PPERF_DATA_BLOCK = ^TPERF_DATA_BLOCK;

TPERF_OBJECT_TYPE = record
TotalByteLength : DWORD;
DefinitionLength : DWORD;
HeaderLength : DWORD;
ObjectNameTitleIndex : DWORD;
ObjectNameTitle : LPWSTR;
ObjectHelpTitleIndex : DWORD;
ObjectHelpTitle : LPWSTR;
DetailLevel : DWORD;
NumCounters : DWORD;
DefaultCounter : Longint;
NumInstances : Longint;
CodePage : DWORD;
PerfTime : TInt64;
PerfFreq : TInt64;
end;

PPERF_OBJECT_TYPE = ^TPERF_OBJECT_TYPE;

type
TPERF_COUNTER_DEFINITION = record
ByteLength : DWORD;
CounterNameTitleIndex : DWORD;
CounterNameTitle : LPWSTR;
CounterHelpTitleIndex : DWORD;
CounterHelpTitle : LPWSTR;
DefaultScale : Longint;
DetailLevel : DWORD;
CounterType : DWORD;
CounterSize : DWORD;
CounterOffset : DWORD;
end;

PPERF_COUNTER_DEFINITION = ^TPERF_COUNTER_DEFINITION;

TPERF_COUNTER_BLOCK = record
ByteLength : DWORD;
end;

PPERF_COUNTER_BLOCK = ^TPERF_COUNTER_BLOCK;

TPERF_INSTANCE_DEFINITION = record
ByteLength : DWORD;
ParentObjectTitleIndex : DWORD;
ParentObjectInstance : DWORD;
UniqueID : Longint;
NameOffset : DWORD;
NameLength : DWORD;
end;

PPERF_INSTANCE_DEFINITION = ^TPERF_INSTANCE_DEFINITION;

//------------------------------------------------------------------------------
{$ifdef ver130}
{$L-} // The L+ causes internal error in Delphi 5 compiler
{$O-} // The O+ causes internal error in Delphi 5 compiler
{$Y-} // The Y+ causes internal error in Delphi 5 compiler
{$endif}

{$ifndef ver110}
type
TInt64F = TInt64;
{$else}
type
TInt64F = Extended;
{$endif}

{$ifdef ver110}
function FInt64(Value: TInt64): TInt64F;
function Int64D(Value: DWORD): TInt64;
{$else}
type
FInt64 = TInt64F;
Int64D = TInt64;
{$endif}

{$ifdef ver110}
function FInt64(Value: TInt64): TInt64F;
var V: TInt64;
begin
if (Value.HighPart and $80000000) = 0 then // positive value
begin
result:=Value.HighPart;
result:=result*$10000*$10000;
result:=result+Value.LowPart;
end else
begin
V.HighPart:=Value.HighPart xor $FFFFFFFF;
V.LowPart:=Value.LowPart xor $FFFFFFFF;
result:= -1 - FInt64(V);
end;
end;

function Int64D(Value: DWORD): TInt64;
begin
result.LowPart:=Value;
result.HighPart := 0; // positive only
end;
{$endif}

//------------------------------------------------------------------------------

const
Processor_IDX_Str = '238';
Processor_IDX = 238;
CPUUsageIDX = 6;

type
AInt64F = array[0..$FFFF] of TInt64F;
PAInt64F = ^AInt64F;

var
_PerfData : PPERF_DATA_BLOCK;
_BufferSize: Integer;
_POT : PPERF_OBJECT_TYPE;
_PCD: PPerf_Counter_Definition;
_ProcessorsCount: Integer;
_Counters: PAInt64F;
_PrevCounters: PAInt64F;
_SysTime: TInt64F;
_PrevSysTime: TInt64F;
_IsWinNT: Boolean;

_W9xCollecting: Boolean;
_W9xCpuUsage: DWORD;
_W9xCpuKey: HKEY;


//------------------------------------------------------------------------------
function GetCPUCount: Integer;
begin
if _IsWinNT then
begin
if _ProcessorsCount < 0 then CollectCPUData;
result:=_ProcessorsCount;
end else
begin
result:=1;
end;

end;

//------------------------------------------------------------------------------
procedure ReleaseCPUData;
var H: HKEY;
R: DWORD;
dwDataSize, dwType: DWORD;
begin
if _IsWinNT then exit;
if not _W9xCollecting then exit;
_W9xCollecting:=False;

RegCloseKey(_W9xCpuKey);

R:=RegOpenKeyEx( HKEY_DYN_DATA, 'PerfStats/StopStat', 0, KEY_ALL_ACCESS, H );

if R <> ERROR_SUCCESS then exit;

dwDataSize:=sizeof(DWORD);

RegQueryValueEx ( H, 'KERNEL/CPUUsage', nil, @dwType, PBYTE(@_W9xCpuUsage), @dwDataSize);

RegCloseKey(H);

end;

//------------------------------------------------------------------------------
function GetCPUUsage(Index: Integer): Double;
begin
if _IsWinNT then
begin
if _ProcessorsCount < 0 then CollectCPUData;
if (Index >= _ProcessorsCount) or (Index < 0) then
raise Exception.Create('CPU index out of bounds');
if _PrevSysTime = _SysTime then result:=0 else
result:=1-(_Counters[index] - _PrevCounters[index])/(_SysTime-_PrevSysTime);
end else
begin
if Index <> 0 then
raise Exception.Create('CPU index out of bounds');
if not _W9xCollecting then CollectCPUData;
result:=_W9xCpuUsage / 100;
end;
end;

var VI: TOSVERSIONINFO;

//------------------------------------------------------------------------------
procedure CollectCPUData;
var BS: integer;
i: Integer;
_PCB_Instance: PPERF_COUNTER_BLOCK;
_PID_Instance: PPERF_INSTANCE_DEFINITION;
ST: TFileTime;

var H: HKEY;
R: DWORD;
dwDataSize, dwType: DWORD;
begin
if _IsWinNT then
begin
BS:=_BufferSize;
while RegQueryValueEx( HKEY_PERFORMANCE_DATA, Processor_IDX_Str, nil, nil,
PByte(_PerfData), @BS ) = ERROR_MORE_DATA do
begin
// Get a buffer that is big enough.
INC(_BufferSize,$1000);
BS:=_BufferSize;
ReallocMem( _PerfData, _BufferSize );
end;

// Locate the performance object
_POT := PPERF_OBJECT_TYPE(DWORD(_PerfData) + _PerfData.HeaderLength);
for i := 1 to _PerfData.NumObjectTypes do
begin
if _POT.ObjectNameTitleIndex = Processor_IDX then Break;
_POT := PPERF_OBJECT_TYPE(DWORD(_POT) + _POT.TotalByteLength);
end;

// Check for success
if _POT.ObjectNameTitleIndex <> Processor_IDX then
raise Exception.Create('Unable to locate the "Processor" performance object');

if _ProcessorsCount < 0 then
begin
_ProcessorsCount:=_POT.NumInstances;
GetMem(_Counters,_ProcessorsCount*SizeOf(TInt64));
GetMem(_PrevCounters,_ProcessorsCount*SizeOf(TInt64));
end;

// Locate the "% CPU usage" counter definition
_PCD := PPERF_Counter_DEFINITION(DWORD(_POT) + _POT.HeaderLength);
for i := 1 to _POT.NumCounters do
begin
if _PCD.CounterNameTitleIndex = CPUUsageIDX then break;
_PCD := PPERF_COUNTER_DEFINITION(DWORD(_PCD) + _PCD.ByteLength);
end;

// Check for success
if _PCD.CounterNameTitleIndex <> CPUUsageIDX then
raise Exception.Create('Unable to locate the "% of CPU usage" performance counter');

// Collecting coutners
_PID_Instance := PPERF_INSTANCE_DEFINITION(DWORD(_POT) + _POT.DefinitionLength);
for i := 0 to _ProcessorsCount-1 do
begin
_PCB_Instance := PPERF_COUNTER_BLOCK(DWORD(_PID_Instance) + _PID_Instance.ByteLength );

_PrevCounters:=_Counters;
_Counters:=FInt64(PInt64(DWORD(_PCB_Instance) + _PCD.CounterOffset)^);

_PID_Instance := PPERF_INSTANCE_DEFINITION(DWORD(_PCB_Instance) + _PCB_Instance.ByteLength);
end;

_PrevSysTime:=_SysTime;
SystemTimeToFileTime(_PerfData.SystemTime, ST);
_SysTime:=FInt64(TInt64(ST));
end else
begin
if not _W9xCollecting then
begin
R:=RegOpenKeyEx( HKEY_DYN_DATA, 'PerfStats/StartStat', 0, KEY_ALL_ACCESS, H );
if R <> ERROR_SUCCESS then
raise Exception.Create('Unable to start performance monitoring');

dwDataSize:=sizeof(DWORD);

RegQueryValueEx( H, 'KERNEL/CPUUsage', nil, @dwType, PBYTE(@_W9xCpuUsage), @dwDataSize );

RegCloseKey(H);

R:=RegOpenKeyEx( HKEY_DYN_DATA, 'PerfStats/StatData', 0,KEY_READ, _W9xCpuKey );

if R <> ERROR_SUCCESS then
raise Exception.Create('Unable to read performance data');

_W9xCollecting:=True;
end;

dwDataSize:=sizeof(DWORD);
RegQueryValueEx( _W9xCpuKey, 'KERNEL/CPUUsage', nil,@dwType, PBYTE(@_W9xCpuUsage), @dwDataSize );
end;
end;


initialization
_ProcessorsCount:= -1;
_BufferSize:= $2000;
_PerfData := AllocMem(_BufferSize);

VI.dwOSVersionInfoSize:=SizeOf(VI);
if not GetVersionEx(VI) then raise Exception.Create('Can''t get the Windows version');

_IsWinNT := VI.dwPlatformId = VER_PLATFORM_WIN32_NT;
finalization
ReleaseCPUData;
FreeMem(_PerfData);
end.

不能用TIMER是因为GETCPUUSAGE中已经有循环过程，你把ShowMessage一句删除，然后
在Sleep(1000)前加一句BREAK;就可以用TIMER了。

吕雪松大侠说得没错，用多线程