Hi,

I'm trying to make a TEdit only accept numeric char (0,1,...,9).
Using KeyPress or KeyDown event, trying to inspect char code
to allow or not it didn't work for me ...

"&" code is 49, like "1" one's ... So I'm not easily able to
distinguish between them (and EWB does not propose "in [0..9]" instruction).

Does someone knows a simple way to do that ?

(I have the same problem with a TEdit that only accept [a..b,A..B] ).

Eric.

On 5/3/2014 3:13 PM, E.B wrote:
> I'm trying to make a TEdit only accept numeric char (0,1,...,9).
> Using KeyPress or KeyDown event, trying to inspect char code
> to allow or not it didn't work for me ...

What did you try ?

> Does someone knows a simple way to do that ?

There are couple of ways. The simplest would be something like this in
the edits Keypress :
   if (Key >='0') AND (Key <= '9') then
      result := true
   else
      result := false;

However you'll notice that some letters can still be entered (since
KeyPress is now always called) so better solution would be to to drop
down to KeyDown event. The only problem here is that you likely want to
handle some control codes still (like backspace for example) so try
something like this in edit contrrols KeyDown event:

   result := false;
   if not (shiftkey) then
   begin
      if ( Key >= ord('0') ) AND ( key <= ord('9')) OR (Key=8) OR
(Key=46) then result:= true;
   end;

Raul

Raul wrote:

On 5/3/2014 3:13 PM, E.B wrote:
> I'm trying to make a TEdit only accept numeric char (0,1,...,9).
> Using KeyPress or KeyDown event, trying to inspect char code
> to allow or not it didn't work for me ...

What did you try ?

> Does someone knows a simple way to do that ?

There are couple of ways. The simplest would be something like this in
the edits Keypress :
   if (Key >='0') AND (Key <= '9') then
      result := true
   else
      result := false;

However you'll notice that some letters can still be entered (since
KeyPress is now always called) so better solution would be to to drop
down to KeyDown event. The only problem here is that you likely want to
handle some control codes still (like backspace for example) so try
something like this in edit contrrols KeyDown event:

   result := false;
   if not (shiftkey) then
   begin
      if ( Key >= ord('0') ) AND ( key <= ord('9')) OR (Key=8) OR
(Key=46) then result:= true;
   end;

Raul, the problem doesn't seems to be as simple as that ...

Using my KeyBoard, key=49 when I press [SHIFT "&"] or "1" alone ...

When I press [SHIFT "&"] the char wrote in Tedit is "1"
When I press ["1"] alone the char wrote in Tedit is "&"

In the two case, key=49.

Eric.

E.B wrote:

Raul wrote:

On 5/3/2014 3:13 PM, E.B wrote:
> I'm trying to make a TEdit only accept numeric char (0,1,...,9).
> Using KeyPress or KeyDown event, trying to inspect char code
> to allow or not it didn't work for me ...

What did you try ?

> Does someone knows a simple way to do that ?

There are couple of ways. The simplest would be something like this in
the edits Keypress :
   if (Key >='0') AND (Key <= '9') then
      result := true
   else
      result := false;

However you'll notice that some letters can still be entered (since
KeyPress is now always called) so better solution would be to to drop
down to KeyDown event. The only problem here is that you likely want to
handle some control codes still (like backspace for example) so try
something like this in edit contrrols KeyDown event:

   result := false;
   if not (shiftkey) then
   begin
      if ( Key >= ord('0') ) AND ( key <= ord('9')) OR (Key=8) OR
(Key=46) then result:= true;
   end;

Raul, the problem doesn't seems to be as simple as that ...

Using my KeyBoard, key=49 when I press [SHIFT "&"] or "1" alone ...

When I press [SHIFT "&"] the char wrote in Tedit is "1"
When I press ["1"] alone the char wrote in Tedit is "&"

In the two case, key=49.

Eric.

Sorry Raul I'm a little bit stupid sometime ...
SHIFT key could be use to choose between
the two characters, ok.

So I wrote that using your idea
(it includes numpad):


if (shiftkey) then
begin
   if ( key >= ord('0') ) AND ( key <= ord('9')) then
   result:= true;

end
else
begin
  if (( key >= 96 ) AND ( key <= 105))
     OR (Key=8) OR (Key=46) then
   result:= true;
end;