Question

hi i’m trying to make an editbox move down from 300 by 30 when a button is clicked, and upon clicking the same button again, make editbox move back up by 30 to its original position. However when i click the button ive made it just moves up by 30 each time, where am i going wrong? here is my code,

procedure TfrmProject.Button3Click(Sender: TObject);
begin    
  if Edit1.Top = 300 then 
    Edit1.Top := Edit1.Top + 30 else 
    Edit1.Top := Edit1.Top - 30;    
end; 

EDIT: I have realised that due to my form being long and having a vertical scrollbar, the property Top of the editbox changes in response to where i am on the form, i.e if i’m at the top of my form the Top property of the edit box increases (the editbox is near the bottom of the form), therefore my new question is how could i ensure the editbox only moves between 2 fixed points, as following the recent suggestions the edit box moves between two points with a 30 distance between them, but their positions on the form change.

Answer 1

This works perfectly fine for me.

Create a new Delphi VCL Forms Application

Drop a TEdit and a TButton on the new form. Set the Top' property of each to50using theObject Inspector`.

Double-click Button1, and paste the following code to replace the newly generated TForm1.Button1Click event:

procedure TForm1.Button1Click(Sender: TObject);
begin
  if Edit1.Top = 50 then
    Edit1.Top := Edit1.Top + 30
  else
    Edit1.Top := 50;
end;

Run the application. Repeatedly clicking Button1 makes Edit1 move up and down from 50 to 80.

This means your comparison is wrong. Set the Button1.Top explicitly to the original coordinate (300 in your code) instead of reducing by 30.