[Solved] Creating a class
lazarus / 31-LCL

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iru · 2019-01-23 06:17

Gentlefolk,

I have problem with the understanding/use of classes, specifically the
operation of a create.
From reading and examples the following should create a 'class' based
on tObject.
Compiles clean but when executed
  MB = NIL.
and therefore one gets a SigSev when trying to access ThePanel......

Any explanations and/or examples of correct usage appreciated, Ian.

type

  tMyBut = class
    ThePanel : tPanel;
  public
     constructor Create;
  end;

var
  MB : tMyBut;

implementation

constructor tMyBut.Create;

Begin
  Inherited Create;

end;

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Handoko · 2019-01-23 06:42

It should be something like this:

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i type   {
tMyBut }  tMyBut = class    ThePanel : TPanel;  public     constructor
Create;     destructor Destroy; override;  end; implementation {
tMyBut } constructor tMyBut.Create;begin  inherited Create;  ThePanel
:= TPanel.Create(nil);end; destructor tMyBut.Destroy;begin 
ThePanel.Free;  inherited Destroy;end;
When use it on a form, don't forget to free it:

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i var  Form1
: TForm1;  MB    : tMyBut; implementation {$R *.lfm} { TForm1
} procedure TForm1.FormCreate(Sender: TObject);begin  MB :=
tMyBut.Create;end; procedure TForm1.FormDestroy(Sender:
TObject);begin  MB.Free;end;

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iru · 2019-01-23 23:34

Thank you for the response. and the example code.
So , not much different to what I was doing but it works! I must be
getting old.....

Thanks again, Ian