Mega Code Archive
Assigning property-values at runtime
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Got a question from one ot my visitors recently:
Question: How can I loop through and set properties of components without
manually setting each component separately?
Below is my solution.
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
StdCtrls, ExtCtrls;
type
TForm1 = class(TForm)
Shape1: TShape;
Button1: TButton;
Shape2: TShape;
Shape3: TShape;
Shape4: TShape;
Shape5: TShape;
Shape6: TShape;
Shape7: TShape;
Shape8: TShape;
Shape9: TShape;
Shape10: TShape;
Button2: TButton;
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.DFM}
{
QUESTION:
How can I loop through and set properties of components without
manually setting each component separately?
I am writing a program which uses 10 TShapes.
Currently, I am setting the tag and color properties of these
components as follows.
}
procedure TForm1.Button1Click(Sender: TObject);
begin
Shape1.Shape:= stCircle;
Shape1.Brush.Color:= clRed;
Shape1.Tag:= 0;
Shape2.Shape:= stCircle;
Shape2.Brush.Color:= clRed;
Shape2.Tag:= 1;
Shape3.Shape:= stCircle;
Shape3.Brush.Color:= clRed;
Shape3.Tag:= 2;
Shape4.Shape:= stCircle;
Shape4.Brush.Color:= clRed;
Shape4.Tag:= 3;
Shape5.Shape:= stCircle;
Shape5.Brush.Color:= clRed;
Shape5.Tag:= 4;
Shape6.Shape:= stCircle;
Shape6.Brush.Color:= clRed;
Shape6.Tag:= 5;
Shape7.Shape:= stCircle;
Shape7.Brush.Color:= clRed;
Shape7.Tag:= 6;
Shape8.Shape:= stCircle;
Shape8.Brush.Color:= clRed;
Shape8.Tag:= 7;
Shape9.Shape:= stCircle;
Shape9.Brush.Color:= clRed;
Shape9.Tag:= 8;
Shape10.Shape:= stCircle;
Shape10.Brush.Color:= clRed;
Shape10.Tag:= 9;
end;
{
ANSWER:
Here is one way to do it. This code will do just the same, with only
6 lines of code instead of 30.
}
procedure TForm1.Button2Click(Sender: TObject);
var n: Integer;
begin
for n:= 1 to 10 do
begin
TShape(FindComponent('Shape' + IntToStr(n))).Shape:= stCircle;
TShape(FindComponent('Shape' + IntToStr(n))).Brush.Color:= clRed;
TShape(FindComponent('Shape' + IntToStr(n))).Tag:= n - 1;
end;
end;
end.
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