Solved

ListVies.SaveToFile ??

Posted on 1998-08-25
6
501 Views
Last Modified: 2012-06-22
ListVies.SaveToFile ??

Hi there, I need to save the contents of a ListView with multiply columns, I have thought of
saving each column by coping the contents of a column to a TStringList and then save in a new file, so the file would look something like this

[Column1]
.
.
.
.


[Column2]
.
.
.
.


The file gets rather big, so isn't there a better way to do that?
0
Comment
Question by:koger
6 Comments
 
LVL 5

Expert Comment

by:ronit051397
ID: 1337652
0
 
LVL 4

Accepted Solution

by:
erajoj earned 50 total points
ID: 1337653
Hi,
Here's a very simple solution, using TStringList.CommaText:

procedure TForm1.Button1Click(Sender: TObject); // save
var
  List1, List2: TStringList;
  iRow, iCol  : Integer;
begin
  List1 := TStringList.Create;
  List2 := TStringList.Create;
  for iRow := 0 to ListView1.Items.Count - 1 do
  with ListView1.Items[ iRow ] do begin
    List1.Add( Caption );
    for iCol := 0 to SubItems.Count - 1 do List1.Add( SubItems[ iCol ] );
    List2.Add( List1.CommaText );
    List1.Clear;
  end;
  List2.SaveToFile( 'c:\listviewcontents.dat' );
  List1.Free;
  List2.Free;
  ListView1.Items.Clear; // not necessary except for this example...
end;

procedure TForm1.Button2Click(Sender: TObject); // load
var
  List1, List2: TStringList;
  iRow, iCol  : Integer;
begin
  List1 := TStringList.Create;
  List2 := TStringList.Create;
  List2.LoadFromFile( 'c:\listviewcontents.dat' );
  ListView1.Items.BeginUpdate;
  for iRow := 0 to List2.Count - 1 do
  with ListView1.Items.Add do begin
    List1.CommaText := List2[ iRow ];
    if List1.Count > 0 then begin
      Caption := List1[ 0 ];
      for iCol := 1 to List1.Count - 1 do SubItems.Add( List1[ iCol ] );
    end;
  end;
  List1.Free;
  List2.Free;
  ListView1.Items.EndUpdate;
end;

/// John
0
 

Expert Comment

by:lavar
ID: 1337654
var
  Stream: TFileStream;
begin
{++Save ListView items++}
Stream := TFileStream.Create('ListView1.dat', fmCreate);
Stream.WriteComponentRes('Items', ListView1);
Stream.Destroy;

{++Load ListView items++}
Stream := TFileStream.Create('ListView1.dat', fmOpenRead);
Stream.ReadComponentRes(ListView1);
Stream.Destroy;
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.

 

Author Comment

by:koger
ID: 1337655
Very good answer

The only problem is that the code is very very slow, it can take more than ten minuttes to load a file with about 1000 columns and 8 rows, the problem is not your code, but TListView's add procedure it's very slow I have tried using AllocBy, but it didn't help.
0
 
LVL 4

Expert Comment

by:erajoj
ID: 1337656
Hi,
I think there are some speed improved listviews on DSP or Torry's.
Look them up, I hope they might speed up things for you...
You can also use beginupdate/endupdate on the TStringLists to speed up things some.

/// John
0
 

Expert Comment

by:menorcanet
ID: 23252367
lavar's code works really well, just what I was looking for. thanks!
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

Suggested Solutions

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…
In this tutorial I will show you how to use the Windows Speech API in Delphi. I will only cover basic functions such as text to speech and controlling the speed of the speech. SAPI Installation First you need to install the SAPI type library, th…
I designed this idea while studying technology in the classroom.  This is a semester long project.  Students are asked to take photographs on a specific topic which they find meaningful, it can be a place or situation such as travel or homelessness.…
Concerto provides fully managed cloud services and the expertise to provide an easy and reliable route to the cloud. Our best-in-class solutions help you address the toughest IT challenges, find new efficiencies and deliver the best application expe…

919 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

21 Experts available now in Live!

Get 1:1 Help Now