Lazarus

Programming => LCL => Topic started by: Weitentaaal on November 24, 2020, 03:50:56 pm

Title: Drag And Drop with Two ListBox
Post by: Weitentaaal on November 24, 2020, 03:50:56 pm

Hey Guys

I Have 2 ListBox.

The First 1 Got Accessories witch can be Selected by Drag Droping them into the Second 1,

is There Any Way to Allso make expand it to a DblClick Event.

For Example if u DblClick any item in the Left Box it will appear in the Right(The Second one)

Thanks :)

Title: Re: Drag And Drop with Two ListBox
Post by: lucamar on November 24, 2020, 05:18:44 pm

Use the OnDblClick event. This, for example, is from my "player".

Code: Pascal  [Select][+][-]

1. procedure TMainForm.ListDblClick(Sender: TObject);
2. { Double clicking a filename in the list plays it inmediately }
3. begin
4.   if FileList.ItemIndex >= 0 then
5.     PlaySong(FileList.ItemIndex);
6. end;

FileList is a TListBox and this is its OnDblClick handler. We first check whether there's any element selected and if so, call one of two overloads which accepts a "song" index and calls the other overload with the corresponding item string (a file name):

Code: Pascal  [Select][+][-]

1. procedure TMainForm.PlaySong(const Index: Integer);
2. { Plays the file whose index in the list is Index }
3. begin
4.   if (Index >= 0) and (Index < FileList.Count) then begin
5.     Current := Index;
6.     PlaySong(FileList.Items[Index]);
7.   end;
8. end;

In your case you'd do something like:

Code: Pascal  [Select][+][-]

1. SecondList.Items.Add(FirstList.Items[FileList.ItemIndex])

HTH!

Title: Re: Drag And Drop with Two ListBox
Post by: howardpc on November 24, 2020, 05:42:22 pm

Code: Pascal  [Select][+][-]

1. unit Unit1;
2.  
3. {$mode objfpc}{$H+}
4.  
5. interface
6.  
7. uses
8.   Forms, StdCtrls;
9.  
10. type
11.   TForm1 = class(TForm)
12.     LeftListBox: TListBox;
13.     RightListBox: TListBox;
14.     procedure FormCreate(Sender: TObject);
15.     procedure LeftListBoxDblClick(Sender: TObject);
16.   end;
17.  
18. var
19.   Form1: TForm1;
20.  
21. implementation
22.  
23. {$R *.lfm}
24.  
25. { TForm1 }
26.  
27. procedure TForm1.FormCreate(Sender: TObject);
28. var
29.   i: Integer;
30. begin
31.   for i := 0 to 7 do
32.     LeftListBox.Items.Add('Item # %d', [i]);
33. end;
34.  
35. procedure TForm1.LeftListBoxDblClick(Sender: TObject);
36. begin
37.   if LeftListBox.ItemIndex > -1 then
38.     RightListBox.Items.Add(LeftListBox.Items[LeftListBox.ItemIndex]);
39. end;
40.  
41. end.

Title: Re: Drag And Drop with Two ListBox
Post by: Weitentaaal on November 25, 2020, 10:24:17 am

Thank you Guys :)

Now I know my next Project too. A Music player sounds good :D