Solved

Input Validation

Posted on 1998-11-05
1
348 Views
Last Modified: 2010-04-04
Hi

How do I validate that the contents of an edit box (input by the user) is a positive integer?

Thanks
0
Comment
Question by:cavalry
1 Comment
 
LVL 8

Accepted Solution

by:
ZifNab earned 10 total points
ID: 1345806
Hi cavalry,

3 options :

1. Use Tedit and check the entered value when exiting the editbox
2. Use MaskEdit with an editmask which only allows figures.
3. Use a special designed numeric edit (a lot freewares!)
   --> e.g. One in the freeware RxLib (http://rx.demo.ru)
     

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Edit1: TEdit;
    MaskEdit1: TMaskEdit;
    procedure Edit1Exit(Sender: TObject);
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.DFM}

procedure TForm1.Edit1Exit(Sender: TObject);
begin
 try
  If StrToInt(Edit1.text) < 0 then begin
   ShowMessage('not correct value');
   Edit1.Text := '0';
  end;
 except
  // Edit1.Text contains chars
   ShowMessage('fill in only an integer value');
   Edit1.Text := '0';
 end;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
 Edit1.text := '0';
 MaskEdit1.EditMask:= '00000;1;';   {or 999999;1; }
end;

end.

Regards, Zif.

0

Featured Post

Free Tool: Path Explorer

An intuitive utility to help find the CSS path to UI elements on a webpage. These paths are used frequently in a variety of front-end development and QA automation tasks.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
how to center only a line in richedit? 4 69
Delphi: Connect to running MS Outlook 4 165
DBGrid or StringGrid ? 6 120
Not able to call Delphi XE10 dll function from Delphi 6.0 4 49
A lot of questions regard threads in Delphi.   One of the more specific questions is how to show progress of the thread.   Updating a progressbar from inside a thread is a mistake. A solution to this would be to send a synchronized message to the…
Hello everybody This Article will show you how to validate number with TEdit control, What's the TEdit control? TEdit is a standard Windows edit control on a form, it allows to user to write, read and copy/paste single line of text. Usua…
In a recent question (https://www.experts-exchange.com/questions/29004105/Run-AutoHotkey-script-directly-from-Notepad.html) here at Experts Exchange, a member asked how to run an AutoHotkey script (.AHK) directly from Notepad++ (aka NPP). This video…
Are you ready to implement Active Directory best practices without reading 300+ pages? You're in luck. In this webinar hosted by Skyport Systems, you gain insight into Microsoft's latest comprehensive guide, with tips on the best and easiest way…

733 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question