Component writing question

I don't think it is possible to have a varying number of properties for a component when viewed by the object inspector at design time - so to do exactly what you describe is not IMO feasible.

Why do you want to do this? And is your question regarding enumerating the drives, creating the component or showing varying properties in the inspector.

Cheers,

Raymond.

Can't help you with the Property Editor stuff, but storing the list is relative easy.
Declare a object that holds all the drive info (vollabel, diskfree..) and then for every drive, create an instance of the object and when you are adding the drive to the list, use AddObject instead of Add. Now, when you click on a drive, a pointer to your object is stored in Items.Objects[no] and you can then typecast it to your object and retreive the information you want..
If you want an example, just say so...

Stuart,

type
  TDriveProp = class(TObject)
  private
    FDrive    : char;
    FVolLabel : string;
    FSerialNo : integer;
    ...
  private
    procedure SetStringDummy(value: string);
    procedure SetIntDummy(value: integer);
    ...
  public
    constructor Create(drive: char); virtual;
  published
    property VolLabel : string  read FVolLabel write SetStringDummy;
    property SerialNo : integer read FSerialNo write SetIntDummy;
    ...
  end;

constructor TDriveProp.Create(drive: char); virtual;
begin
  inherited;
  FDrive:=drive;
  // Fill FVolLabel, FSerialNo, ...
end;

type
  TDrives = class(TComponent)
  private
    FDriveProps : array ['A'..'Z'] of TDriveProp;
    function  GetDriveProp(index: integer) : TDriveProp;
    procedure SetDriveProp(index: integer; value: TDriveProp);
  protected
  public
    constructor Create(AOwner: TComponent); override;
    destructor Destroy; override;
  published
    property DriveA : TDriveProp index 0 read GetDriveProp write SetDrivePop;
    property DriveB : TDriveProp index 1 read GetDriveProp write SetDrivePop;
    property DriveC : TDriveProp index 2 read GetDriveProp write SetDrivePop;
    property DriveD : TDriveProp index 3 read GetDriveProp write SetDrivePop;
    property DriveE : TDriveProp index 4 read GetDriveProp write SetDrivePop;
    ...
  end;

constructor TDrives.Create(AOwner: TComponent);
var ch : char;
begin
  inherited;
  for ch:='A' to 'Z' do
    FDriveProps[ch]:=TDriveProp.Create(ch);
end;

destructor TDrives.Destroy;
begin
  for ch:='A' to 'Z' do
    FDriveProps[ch].Free;
  inherited;
end;

procedure TDrives.SetDriveProp(index: integer; value: TDriveProp); begin end;

function TDrives.GetDriveProp(index: integer) : TDriveProp;
begin
  result:=FDriveProps[char(index+ord('A'))];
end;

Note, that (AFAIK) you'll have to show all 'A'..'Z' drives in the object inspector.
Don't delete the dummy write procedures. Otherwise the properties will not be visible in the object inspector.
Furthermore I'm not sure, if you can put this drives component  into the property of another component (that's what you wanted, isn't it?). I think it is NOT possible. I think you can only have ONE "V".

Regards, Madshi.

I like Madshi's idea, but I also like the idea of the list.  With the list, is it possible to view them in a dropdown list?  So, if I had five drives (A, C, D, E and Z) they would all be listed in the dropdown list???

I'll have a play with Madshi's idea now and see what I come up with.

Stu.

Thaddy.  How would I incorperate that in the component.  Sorry for the naivity, but this sort of thing is over my head a bit :)

Stu.

You simply derive from Tcomponent and add the TdriveCollection as a property
Delphi itself registers this as a Collection (Like Tmenu or Tactionlist) and voila you even have a propertyeditor.

Look at How Tactionlist is implemented in the VCL, then you get the Idea. What you need is even simpler.

Thaddy,

As yet, I havent implemented your idea, and I dont know when and if I will.  I have given you the points regardless.

Thanks all for the help.

Stu.