🚀 go-pugleaf

On 8 ���, 19:31, Poetj...@gmail.com wrote:
> hi, i have a question,
> if i try to run the following code i get the error "Left side cannot
> be assigned to".
> i understand that this has something to do with the usage of TypeA.
> My question is, how can you pass records to components? because,
> apparently, the following approach does not work.
>
> thank you all in advance,
>
> Type TypeA=record
>   some_int:integer;
>   some_real:real;
>   end;
>
> Type TypeB = class(TComponent)
>   private
>     PrivateA: array of TypeA;
>     function GetA(index:integer):TypeA;
>     procedure SetA(index:integer;value:TypeA);
>
>   public
>     procedure SetLengthA(i:integer);
>     property A[i:integer]:TypeA read GetA write SetA;
>   end;
>
> procedure TypeB.SetLengthA(i:integer);
> begin
>   setlength(PrivateA,i);
> end;
>
> function TypeB.GetA(index:integer):TypeA;
> begin
>   result:=PrivateA[index];
> end;
>
> procedure TypeB.SetA(index:integer;value:TypeA);
> begin
>   PrivateA[index]:=value;
> end;
>
> procedure TForm1.Button1Click(Sender: TObject);
> var B: TypeB;
> begin
>   B:=TypeB.create(nil);
>   B.SetLengthA(3);
>   B.A[1].some_int:=5;   //   <----------- this causes the error !
> end;

1. use pointer to record TTypeA like
type
  PTypeA = ^TTypeA;

2. use "array of PTypeA" instead of "array of TTypeA"
3. don't  forget to allocate memory for all elements of that array