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unit EnumSerialPorts;

{

Модуль перечисления последовательных портов.

Используется WMI, берется минимальная информация.

$Author: Roman $

$Date:: 2012-02-21 15:37:00#$

}

interface

uses SysUtils, Generics.Collections, ActiveX;

type

TSerialPortInfo = record

Caption: string;

DeviceID: string;

MaxBaudRate: cardinal;

ProviderType: string;

end;

TSerialPortEnum = class(TEnumerable<TSerialPortInfo>)

strict private

FWMIService: Variant;

protected

function DoGetEnumerator: TEnumerator<TSerialPortInfo>; override;

type

TPortEnum = class(TEnumerator<TSerialPortInfo>)

strict private

FEnum: IEnumVARIANT;

FCurrentElem: OleVariant;

protected

function DoGetCurrent: TSerialPortInfo; override;

function DoMoveNext: Boolean; override;

public

constructor Create(Enum: IEnumVariant);

destructor Destroy; override;

end;

public

constructor Create;

destructor Destroy; override;

end;

implementation

uses COMObj, Variants;

//стандартные флаги для запроса

const

wbemFlagForwardOnly = ;

wbemFlagBidirectional = {text};

wbemFlagReturnImmediately = ;

wbemFlagReturnWhenComplete = {text};

wbemQueryFlagPrototype = ;

wbemFlagUseAmendedQualifiers = 000;

function GetVariantEnumerator(obj: Variant): IEnumVariant;

var

Enum: IUnknown;

begin

Enum := obj._NewEnum;

OleCheck(Enum.QueryInterface(IEnumVariant, Result));

end;

function GetObject(const ObjName: WideString): Variant;

var

Temp: IDispatch;

begin

OleCheck(CoGetObject(PWideString(ObjName), nil, IDispatch, @Temp));

Result := Temp;

end;

{ TSerialPortList }

const

strMonName: WideString = 'winmgmts:\.\root\CIMV2';

strQueryList: WideString = 'SELECT * FROM Win32_SerialPort';

constructor TSerialPortEnum.Create;

begin

inherited;

FWMIService := GetObject(strMonName);

end;

destructor TSerialPortEnum.Destroy;

begin

FWMIService := Unassigned;

inherited;

end;

function TSerialPortEnum.DoGetEnumerator: TEnumerator<TSerialPortInfo>;

var

Items: OleVariant;

begin

Items := FWMIService.ExecQuery(strQueryList, 'WQL', wbemFlagForwardOnly);

Result := TPortEnum.Create(GetVariantEnumerator(Items));

end;

{ TSerialPortList.TPortEnum }

constructor TSerialPortEnum.TPortEnum.Create(Enum: IEnumVariant);

begin

inherited Create;

FEnum := Enum;

end;

destructor TSerialPortEnum.TPortEnum.Destroy;

begin

FEnum := nil;

inherited;

end;

function TSerialPortEnum.TPortEnum.DoGetCurrent: TSerialPortInfo;

begin

Result.Caption := FCurrentElem.Caption;

Result.DeviceID := FCurrentElem.DeviceID;

Result.MaxBaudRate := FCurrentElem.MaxBaudRate;

Result.ProviderType := FCurrentElem.ProviderType;

end;

function TSerialPortEnum.TPortEnum.DoMoveNext: Boolean;

var

Fetched: Cardinal;

begin

Result := (FEnum.Next(1, FCurrentElem, Fetched) = S_OK);

end;

end.