Simple Array(open?) Question

[MarsTeam]

Hello,

first let me say I tried googling and all, but I still haven't figured out solution to this problem.

Basically, what I want to do, is to have a class, which takes upon construction open array as a parameter so we can send it any arrays(like [0..3] [2..10] etc...).
But then, in class, I want to have a variable which would represent this array. So upon construction, a pointer to that open array is stored, and I can later do like for low(arr) to high(arr) - somewhere outside of contructor, without the need to always pass it as open array.

I've managed to do something like this, but while I understand why it doesn't work, I can't figure out how to do it right.

Code: [Select]

TTest = class
    public
      constructor Create(const vBitmap: array of TBitmap);
 
    private
    Array: array of TBitmap;
end;     

constructor TTest.Create(const vBitmap: array of TBitmap);
begin
  Array := vBitmap;
end;     
This returns:

Error: Incompatible types: got "Open Array Of TBitmap" expected "Dynamic Array Of TBitmap"

- I must have open array in constructor as parameter.
- I must be later able to work with this array which was passed into constructor, so I must store it somewhere, but only as a pointer.

Thanks for help.

[Laksen]

Try this

Code: [Select]

TBitmapArray = array of TBitmap; // Explicit dynamic array declaration

TTest = class
    public
      constructor Create(const vBitmap: TBitmapArray);
 
    private
    Array: TBitmapArray;
end;    

constructor TTest.Create(const vBitmap: TBitmapArray);
begin
  Array := vBitmap;
end;


[Leledumbo]

Code: [Select]

constructor Create(const vBitmap: array of TBitmap);Here, vBitmap is an open array.

Code: [Select]

private
    Array: array of TBitmap;But here Array is dynamic array. Anyway, you shouldn't be able to use Array as attribute name since it's a reserved word.

I'm not sure about the lifetime of open arrays, so my idea is to make a copy of the passed open array instead (warning, untested code):

Code: [Select]

Array := Copy(vBitmap,Low(vBitmap),Length(vBitmap));


[typo]

Copy for arrays returns an error.

[Tom83]

As written above, you can't use the word Array as an identifier, so first of all you have to change the name of the attribute Array, for example to Bitmaps:

Code: [Select]

private
  Bitmaps: array of TBitmap;

Then try to write the constructor like this:

Code: [Select]

constructor TTest.Create(const vBitmap: TBitmapArray);
var I: Integer;
begin
  SetLength(Bitmaps,Length(vBitmap));
  for I:=0 to Length(vBitmap) - 1 do
    Bitmaps[I] := vBitmap[I];
end;