free components at runtime 1

[DelphiAaron]

something so simple i cant do.

how do i free all components created at runtime ?

this gives a list index out of bounds error if theres more than 1 control.

var i:integer;
begin
for i:= 0 to ScrollBox1.ControlCount -1 do
ScrollBox1.Controls.free;
end;


Aaron Taylor
John Mutch Electronics

http://www.jme.com.au

 

[DelphiAaron]

typical, you always find the answer 2 seconds after posting the question.

for anyone interested its

for I := ScrollBox1.ComponentCount - 1 downto 0 do
ScrollBox1.Controls.free;

Aaron Taylor
John Mutch Electronics

http://www.jme.com.au

 

[whosrdaddy]

or you can do this (I dislike for-loops :

while ScrollBox1.ComponentCount > 0 do
 FreeAndNil(ScrollBox1.Controls[0]);

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[DelphiAaron]

didnt like that but this worked

while ScrollBox1.ComponentCount > 0 do
ScrollBox1.Controls[0].free;

Aaron Taylor
John Mutch Electronics

http://www.jme.com.au

 

[whosrdaddy]

Using FreeAndNil() function assures that memory is actually released by the memory manager...

-----------------------------------------------------
What You See Is What You Get
Never underestimate tha powah of tha google!

 

[DelphiAaron]

im not saying i dont like it
delphi didnt.

Error: Constant object cannot be passed as var parameter

Aaron Taylor
John Mutch Electronics

http://www.jme.com.au

 

[sggaunt]

Whats the problem with for-loops daddy?
Controllable, Optimised, etc..

Steve: Delphi a feersum engin indeed.

 

[whosrdaddy]

I don't have anything against for-loop really. but there are cases where they can be avoided. I saves me to declare an index variable in some routines, which is a bit faster (no stack frame).

I work a lot with 0 index based lists and I always use the same method.

consider this code :

 ...
 for Index:=0 to SomeList.Count-1 do
  begin
   dosomework(Index);
  end;

sometimes I forgot do the -1 part (which caused me alot of headaches in BIG loops, although this is an obvious error)

so I use this standard method:

 ...
 Index:=SomeList.Count;
 while Count > 0 do
 begin
  Dec(Index);
  dosomework(Index);  
 end;

Writing code this way prevented me from writing incorrect code.

I am not saying I'm against using for-loops , for me, it's more like a habit not using them anymore, I think...

My 2 cents,
Daddy

-----------------------------------------------------
What You See Is What You Get
Never underestimate tha powah of tha google!

 

[whosrdaddy]

forgot saying one thing in my previous post,

with for loops, you NEED to check the List.Count property, because when Count is 0, you'll get a rangecheck error on the for-loop. this check is automatically done using the while loop...

-----------------------------------------------------
What You See Is What You Get
Never underestimate tha powah of tha google!