delphi 4 "if trim(edit1.text)=....." -is integer? 4

[minchite]

i need the correct syntax to ask delphi 4 if an edit.text is an integer value.
Please help me. Thanks.

 

[svanels]

You want to enter only numbers in the edit field?
select the onkeypress event:

procedure TForm1.Edit1KeyPress(Sender: TObject; var Key: Char);
begin
if ((Key < '0') or (Key > '9')) and (Key <> #13) then
key := #0; //backspace
end;


obs: this is only for positive integers

Regards S. van Els
SAvanEls@cq-link.sr

 

[bearsite4]

You could use the StrToInt function which converts a string to and integer. If the string does not contain a valid integer representation then an exception will be thrown which will let your program know that the text is not an integer value.

 

[ThomLemon]

Both of these are good suggestions depending on what you want. The first will make it impossible for a user to even type a non-numeric character into the edit box. The other will let you know if they have used non-numeric characters after they have entered the data.