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Array of pointers to functions

Posted on 2006-06-18
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Last Modified: 2010-04-05
Let`s say I have these functions:

function A(v1, v2: Integer): boolean;
function B(v1: Integer): boolean;
function C: boolean;

I want an array like this:
Functions: Array[1..3] of pointer_to_functions;
then I want to point the array to those function and give me an example how to call the functions from the array.

Should be simple.

Thanks
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Question by:crystyan
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2 Comments
 
LVL 6

Accepted Solution

by:
Amir Azhdari earned 1000 total points
ID: 16929560
unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    procedure Button1Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  procedure Event1(Sender:tobject);
  procedure Event2(Sender:Tobject);
  procedure Event3(Sender:Tobject);
  function A(v1, v2: Integer): boolean;
  function B(v1: Integer): boolean;
  function C: boolean;

  end;

var
  Form1: TForm1;


implementation

{$R *.dfm}

procedure TForm1.Event1(Sender:Tobject);
begin
   A(10,100);
   showmessage('Event1 Activated');
end;

procedure TForm1.Event2(Sender:Tobject);
begin
  B(1000);
  showmessage('Event2 Activated');
end;

procedure TForm1.Event3(Sender:Tobject);
begin
  C;
  showmessage('Event3 Activated');
end;




function TForm1.A(v1, v2: Integer): boolean;
begin
  Result:=v1<v2;
end;


function TForm1.B(v1: Integer): boolean;
begin
  Result:=v1<100;
end;

function tform1.C: boolean;
begin
  Result:=False;
end;


var Functions: Array[1..3] of  TNotifyEvent;

procedure TForm1.Button1Click(Sender: TObject);
begin
  case strtoint(InputBox('Which event you want to point to For Button2Click Event','Which event you want to point to For Button2Click Event :(1/2/3)','1')) of
      1: button2.OnClick:=functions[1];
      2: button2.OnClick:=functions[2];
      3: button2.OnClick:=functions[3];
     else
      showmessage('Error!, out of Range(1 or 2 or 3)');
   end;


end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  Functions[1]:=Event1;
  Functions[2]:=Event2;
  Functions[3]:=Event3;
end;

end.


//////////////////////////////////
DFM
//////////////////////////////////

object Form1: TForm1
  Left = 192
  Top = 114
  Width = 696
  Height = 480
  Caption = 'Form1'
  Color = clBtnFace
  Font.Charset = DEFAULT_CHARSET
  Font.Color = clWindowText
  Font.Height = -11
  Font.Name = 'MS Sans Serif'
  Font.Style = []
  OldCreateOrder = False
  OnCreate = FormCreate
  PixelsPerInch = 96
  TextHeight = 13
  object Button1: TButton
    Left = 80
    Top = 32
    Width = 75
    Height = 25
    Caption = 'Button1'
    TabOrder = 0
    OnClick = Button1Click
  end
  object Button2: TButton
    Left = 257
    Top = 29
    Width = 75
    Height = 25
    Caption = 'Button2'
    TabOrder = 1
  end
end
0
 
LVL 27

Expert Comment

by:kretzschmar
ID: 16934308
hmm,
not the solution i had guessed . . .
0

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