Solved

Edit boxes 'n' case statements.

Posted on 1998-11-21
6
124 Views
Last Modified: 2010-04-04
I need a simple case statement for locking out everything but letters on an edit box's key-press. It's real easy but i've forgotten. PLEASE HELP ME!!!
0
Comment
Question by:Mr_Plasmo
6 Comments
 
LVL 3

Expert Comment

by:philipleighs
ID: 1347492
I the KeyDown event, type:

case Key of
VK_A..VK_Z:
   begin
       //do nothing to allow key to be typed
   end;
else
    begin
          //Next line will prevent char allearing in edit box
         Key := 0;
    end;
end;


There you have it. If you don't like windows VK_ constants, you can replace it with Ord('A')..Ord('Z')

Cheers,
Phil.

0
 
LVL 5

Expert Comment

by:scrapdog
ID: 1347493
This doesn't work.  You would probably have to declare a new class and use the WM_KEYDOWN message.
0
 
LVL 27

Expert Comment

by:kretzschmar
ID: 1347494
hi Mr_Plasmo,

that's no case-statement, but this is a simple solution to allow only letters,

procedure TForm1.Edit1KeyPress(Sender: TObject; var Key: Char);
const validchars : set of char = ['A'..'Z','a'..'z'];
begin
  if not(key in validchars) then key := #0;
end;

meikl
0
Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

 
LVL 10

Accepted Solution

by:
viktornet earned 50 total points
ID: 1347495
YOu can simple do

OnKeyPress()
begin
  if not (key in ['a'..'z', 'A'..'Z']) then key := #0;
end;

which is what meikl proposed,...
0
 
LVL 5

Expert Comment

by:scrapdog
ID: 1347496
procedure TForm1.Edit1KeyPress(Sender: TObject; var Key: Char);
begin
  if not (key in ['a'..'z', 'A'..'Z', #8]) then key := #0;
end;


I would suggest including #8 so the user can backspace.
0
 
LVL 10

Expert Comment

by:viktornet
ID: 1347497
You deserve the points little man :o)
0

Featured Post

Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

Question has a verified solution.

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

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…
Introduction I have seen many questions in this Delphi topic area where queries in threads are needed or suggested. I know bumped into a similar need. This article will address some of the concepts when dealing with a multithreaded delphi database…
This Micro Tutorial will give you a basic overview how to record your screen with Microsoft Expression Encoder. This program is still free and open for the public to download. This will be demonstrated using Microsoft Expression Encoder 4.
Windows 10 is mostly good. However the one thing that annoys me is how many clicks you have to do to dial a VPN connection. You have to go to settings from the start menu, (2 clicks), Network and Internet (1 click), Click VPN (another click) then fi…

920 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

Need Help in Real-Time?

Connect with top rated Experts

14 Experts available now in Live!

Get 1:1 Help Now