Solved

Drag Up or Down Position of a Listview Entry

Posted on 2009-05-14
10
286 Views
Last Modified: 2012-05-07
Hi I'd like to be able to move a listview item up and down the listview. is there anyway of doing this with a mouse or button?

for example, to rearrange the items in an order of choice.
0
Comment
Question by:eNarc
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 4
  • 3
  • 2
10 Comments
 
LVL 12

Accepted Solution

by:
Hypo earned 300 total points
ID: 24386537
Hi,
I don't know if there is any way to alter the index of a ListItem, at least It doesn't seem to at first glance, and maybe that's because the ListView is tightly connected to the WinAPI. Anyway, If you can handle that the ListItems will be destroyed and then recreated when moved, then you could move the items with drag n drop. See the example below, it shows you how you can move the items by deleting and recreating the items.

regards
Hypo.
unit Unit1;
 
interface
 
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, ComCtrls;
 
type
  TForm1 = class(TForm)
    procedure ListViewDragOver(Sender, Source: TObject; X, Y: Integer; State: TDragState; var Accept: Boolean);
    procedure ListViewDragDrop(Sender, Source: TObject; X, Y: Integer);
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
 
var
  Form1: TForm1;
 
implementation
 
{$R *.dfm}
 
procedure TForm1.FormCreate(Sender: TObject);
var i : Integer;
    aListView : TListView;
 
begin
  // ListViewA
  aListView := TListView.Create(Self);
  aListView.Parent := Self;
  aListView.BoundsRect := Rect(10, 10, 200, 300);
  aListView.ViewStyle := vsReport;
  aListView.DragMode := dmAutomatic;
  aListView.OnDragOver := ListViewDragOver;
  aListView.OnDragDrop := ListViewDragDrop;
  aListView.MultiSelect := True;
  for i := 0 to 5 do
    aListView.Items.Add.Caption := 'ListViewA '+IntToStr(Random(100));
  With aListView.Columns.Add do begin
    Width := 100;
    Caption := 'Items';
  end;
 
  // ListViewB
  aListView := TListView.Create(Self);
  aListView.Parent := Self;
  aListView.BoundsRect := Rect(210, 10, 420, 300);
  aListView.ViewStyle := vsReport;
  aListView.DragMode := dmAutomatic;
  aListView.OnDragOver := ListViewDragOver;
  aListView.OnDragDrop := ListViewDragDrop;
  aListView.MultiSelect := True;
  for i := 0 to 5 do
    aListView.Items.Add.Caption := 'ListViewA '+IntToStr(Random(100));
  With aListView.Columns.Add do begin
    Width := 100;
    Caption := 'Items';
  end;
end;
 
procedure TForm1.ListViewDragOver(Sender, Source: TObject; X, Y: Integer; State: TDragState; var Accept: Boolean);
begin
  Accept := (Sender is TListView) and (Source is TListView);
end;
 
procedure TForm1.ListViewDragDrop(Sender, Source: TObject; X, Y: Integer);
var i : Integer;
    aItem : TListItem;
    aTarget : TListView;
    aSource : TListView;
    aSelected : TList;
begin
  aSelected := TList.Create;
  try
    aTarget := Sender as TListView;
    aSource := Source as TListView;
 
    aTarget.Items.BeginUpdate;
    aSource.Items.BeginUpdate;
    // Extract what items are selected...
    for i := 0 to aSource.Items.Count-1 do
      if aSource.Items[i].Selected then
        aSelected.Add(aSource.Items[i]);
    // Get what position item we will above at...
    aItem := aTarget.GetItemAt(X, Y);
 
    // Move items to new listview...
    if Assigned(aItem) then begin
      for i := 0 to aSelected.Count-1 do
        aTarget.Items.Insert(aItem.Index).Assign(aSelected[i]);
    end else begin
      for i := 0 to aSelected.Count-1 do
        aTarget.Items.Add.Assign(aSelected[i]);
    end;
    // Remove source items...
    for i := 0 to aSelected.Count-1 do
      TObject(aSelected[i]).Free;
 
    aItem := aTarget.GetItemAt(X, Y);
    if Assigned(aItem) then
      aItem.Focused := True;
  finally
    aSource.Items.EndUpdate;
    aTarget.Items.EndUpdate;
    aSelected.Free;
  end;
end;
 
end.

Open in new window

0
 
LVL 1

Assisted Solution

by:KillerCode
KillerCode earned 200 total points
ID: 24388599
maybe this will help



function MoveListViewItem(ListView: TListView; ItemFrom, ItemTo: Word): Boolean;
var
  Source, Target: TListItem;
begin
  listview.Items.BeginUpdate;
  try
    Source := ListView.Items[ItemFrom];
    Target := ListView.Items.Insert(ItemTo);
    Target.Assign(Source);
    Target.Selected := True;
    Source.Free;
    Result := True;
  finally
    ListView.Items.EndUpdate;
  end;
end;
 
//Move Down
 if ListView1.Selected <> nil then
  MoveListViewItem(ListView1, ListViewIP1.Selected.Index, ListView1.Selected.Index + 2);
 
//Move Up
 if ListView1.Selected <> nil then
  MoveListViewItem(ListView1, ListView1.Selected.Index, ListView1.Selected.Index -1);

Open in new window

0
 
LVL 5

Author Comment

by:eNarc
ID: 24388661
wow not only does your code drag it also able to drag it into another listview :D thankyou thankyou thankyou :D

I searched "ListViewDragDrop" on google and found this

http://delphi.about.com/od/vclusing/a/arrangelistview.htm 

and I thought it would be relevant to add this for future :D
0
Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 
LVL 5

Author Comment

by:eNarc
ID: 24388797
oh no, I need an admin to fix this I made a mistake when finalizing.
0
 
LVL 5

Author Comment

by:eNarc
ID: 24389223
how does one use that code KillerCode? were do I put it?
0
 
LVL 1

Expert Comment

by:KillerCode
ID: 24389275
u can add it to 2 Buttons next to the listview, or in a PopUpMenu, ill see what i can do with ur other topic now
0
 
LVL 1

Expert Comment

by:KillerCode
ID: 24389357
or thats another thing??
if i didnt get what u mean explain me more plz
0
 
LVL 12

Expert Comment

by:Hypo
ID: 24389651
Ohh, ok... but you got it to work at least?
/Hypo
0
 
LVL 5

Author Comment

by:eNarc
ID: 24399807
thanks coolleomod :D


Hypo: hell yea it works :D it was awesome your code its does exactly what I ask :D being able to move the items from 1 listview to the other is wow! I totally can use that in other apps too :D thankyou thankyou thankyou

KillerCode: your code works too, and is great, I love functions they do make everything easier, almost everything I've coded has a function makes everything a complete package :D

0

Featured Post

Free Tool: Port Scanner

Check which ports are open to the outside world. Helps make sure that your firewall rules are working as intended.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Objective: - This article will help user in how to convert their numeric value become words. How to use 1. You can copy this code in your Unit as function 2. than you can perform your function by type this code The Code   (CODE) The Im…
Introduction Raise your hands if you were as upset with FireMonkey as I was when I discovered that there was no TListview.  I use TListView in almost all of my applications I've written, and I was not going to compromise by resorting to TStringGrid…
There are cases when e.g. an IT administrator wants to have full access and view into selected mailboxes on Exchange server, directly from his own email account in Outlook or Outlook Web Access. This proves useful when for example administrator want…
This is my first video review of Microsoft Bookings, I will be doing a part two with a bit more information, but wanted to get this out to you folks.

729 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