Title: Use try - except
Look my example unit below:
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
StdCtrls;
type
TForm1 = class(TForm)
Edit1: TEdit;
Button1: TButton;
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.DFM}
procedure TForm1.Button1Click(Sender: TObject);
var
I : Integer;
begin
try
//Lets try for a while
I := StrToInt(Edit1.Text);
except
// if Error during conversion, exec this
// if no Error... just Pass it!!!
on E: EConvertError do
ShowMessage('Not a Valid Number');
end;
ShowMessage('Value =' + IntToStr(I));
end;
end.