how to pass a record to a component?

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#164

From: Poetje78
Date: Thu, 08 Mar 2007 16:31

47 lines
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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;

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Subject: how to pass a record to a component?
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