Open CD forklaring!

Der er efterhånden en del tråde med, hvordan man nu engang åbner CD-drevet, men der er aldrig nogen, der forklarer, hvad koden betyder!

Er der ikke en, der vil forklarer, hvad nedenstående kode betyder? altså linje for linje!



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// The OpenCD function
// use like: OpenCD ('DRIVE') (F.eks. OpenCD('E'))

function OpenCD(Drive : Char) : Boolean;
Var
Res : MciError;
OpenParm: TMCI_Open_Parms;
Flags : DWord;
S : String;
DeviceID : Word;
begin
Result:=false;
S:=Drive+':';
Flags:=mci_Open_Type or mci_Open_Element;
With OpenParm do begin
dwCallback := 0;
lpstrDeviceType := 'CDAudio';
lpstrElementName := PChar(S);
end;
Res := mciSendCommand(0, mci_Open, Flags, Longint(@OpenParm));
IF Res<>0 Then exit;
DeviceID:=OpenParm.wDeviceID;
try
Res:=mciSendCommand(DeviceID, MCI_SET, MCI_SET_DOOR_OPEN, 0);
IF Res=0 Then exit;
Result:=True;
finally
mciSendCommand(DeviceID, mci_Close, Flags, Longint(@OpenParm));
end;
end;

// The CloseCD function.
// Use like: CloseCD ('Drive') (F.eks. OpenCD('E'))

function CloseCD(Drive : Char) : Boolean;
Var
Res : MciError;
OpenParm: TMCI_Open_Parms;
Flags : DWord;
S : String;
DeviceID : Word;
begin
Result:=false;
S:=Drive+':';
Flags:=mci_Open_Type or mci_Open_Element;
With OpenParm do begin
dwCallback := 0;
lpstrDeviceType := 'CDAudio';
lpstrElementName := PChar(S);
end;
Res := mciSendCommand(0, mci_Open, Flags, Longint(@OpenParm));
IF Res<>0 Then exit;
DeviceID:=OpenParm.wDeviceID;
try
Res:=mciSendCommand(DeviceID, MCI_SET, MCI_SET_DOOR_CLOSED, 0);
IF Res=0 Then exit;
Result:=True;
finally
mciSendCommand(DeviceID, mci_Close, Flags, Longint(@OpenParm));
end;
end;

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