在DELPHI编的程序中如何找到光驱的盘符?(空)(50分)

为什么不看前面的问题呢？
为了得分，只好再贴一次！

关键是GetDriveType函数

TDriveType = (dtUnknown, dtNoDrive, dtFloppy, dtFixed, dtNetwork, dtCDROM,
dtRAM);

function GetCDROMNumber:integer;
var
DriveNum: Integer;
DriveChar: Char;
DriveType: TDriveType;
DriveBits: set of 0..25;
begin

result := 0;
Integer(DriveBits) := GetLogicalDrives;
for DriveNum := 2 to 25do

begin

if not (DriveNum in DriveBits) then
Continue;
DriveChar := Char(DriveNum + Ord('A'));
DriveType := TDriveType(GetDriveType(PChar(DriveChar + ':/')));
if DriveType = dtCDROM then

Inc(result);
end;

end;



function isCDROM(DriveNum:Integer):Boolean;
var
//DriveNum: Integer;
DriveChar: Char;
DriveType: TDriveType;
DriveBits: set of 0..25;
begin

result := False;
Integer(DriveBits) := GetLogicalDrives;
if (DriveNum in DriveBits) then

begin

DriveChar := Char(DriveNum + Ord('A'));
DriveType := TDriveType(GetDriveType(PChar(DriveChar + ':/')));
if DriveType = dtCDROM then

result:=True;
end;

end;