Пример загрузки файлов в ListView с иконками



Автор: Song
WEB-сайт: http://forum.vingrad.ru

uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms,
Dialogs, comctrls, StdCtrls;
type
TForm1 = class(TForm)
ListView1: TListView;
Button1: TButton;
Button2: TButton;
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
private
procedure SaveListViewToFile(AListView: TListView; sFileName: string);
procedure LoadListViewToFile(AListView: TListView; sFileName: string);
public
end;
const
Msg1 = 'File "%s" does not exist!';
Msg2 = '"%s" is not a ListView file!';
var
Form1: TForm1;
implementation
{$R *.DFM}
procedure TForm1.SaveListViewToFile(AListView: TListView; sFileName: string);
var
idxItem, idxSub, IdxImage: Integer;
F: TFileStream;
pText: PChar;
sText: string;
W, ItemCount, SubCount: Word;
MySignature: array[0..2] of Char;
begin
//Initialization
with AListView do
begin
ItemCount := 0;
SubCount := 0;
//****
MySignature := 'LVF';
// ListViewFile
F := TFileStream.Create(sFileName, fmCreate or fmOpenWrite);
F.Write(MySignature, SizeOf(MySignature));
if Items.Count = 0 then
// List is empty
ItemCount := 0
else
ItemCount := Items.Count;
F.Write(ItemCount, SizeOf(ItemCount));
if Items.Count > 0 then
begin
for idxItem := 1 to ItemCount do
begin
with Items[idxItem - 1] do
begin
//Save subitems count
if SubItems.Count = 0 then
SubCount := 0
else
SubCount := Subitems.Count;
F.Write(SubCount, SizeOf(SubCount));
//Save ImageIndex
IdxImage := ImageIndex;
F.Write(IdxImage, SizeOf(IdxImage));
//Save Caption
sText := Caption;
w := Length(sText);
pText := StrAlloc(Length(sText) + 1);
StrPLCopy(pText, sText, Length(sText));
F.Write(w, SizeOf(w));
F.Write(pText^, w);
StrDispose(pText);
if SubCount > 0 then
begin
for idxSub := 0 to SubItems.Count - 1 do
begin
//Save Item's subitems
sText := SubItems[idxSub];
w := Length(sText);
pText := StrAlloc(Length(sText) + 1);
StrPLCopy(pText, sText, Length(sText));
F.Write(w, SizeOf(w));
F.Write(pText^, w);
StrDispose(pText);
end;
end;
end;
end;
end;
F.Free;
end;
end;
procedure TForm1.LoadListViewToFile(AListView: TListView; sFileName: string);
var
F: TFileStream;
IdxItem, IdxSubItem, IdxImage: Integer;
W, ItemCount, SubCount: Word;
pText: PChar;
PTemp: PChar;
MySignature: array[0..2] of Char;
sExeName: string;
begin
with AListView do
begin
ItemCount := 0;
SubCount := 0;
sExeName := ExtractFileName(sFileName);
if not FileExists(sFileName) then
begin
MessageBox(Handle, PChar(Format(Msg1, [sExeName])), 'I/O Error',
MB_ICONERROR);
Exit;
end;
F := TFileStream.Create(sFileName, fmOpenRead);
F.Read(MySignature, SizeOf(MySignature));
if MySignature <> 'LVF' then
begin
MessageBox(Handle, PChar(Format(Msg2, [sExeName])), 'I/O Error',
MB_ICONERROR);
Exit;
end;
F.Read(ItemCount, SizeOf(ItemCount));
Items.Clear;
for idxItem := 1 to ItemCount do
begin
with Items.Add do
begin
//Read imageindex
F.Read(SubCount, SizeOf(SubCount));
//Read imageindex
F.Read(IdxImage, SizeOf(IdxImage));
ImageIndex := IdxImage;
//Read the Caption
F.Read(w, SizeOf(w));
pText := StrAlloc(w + 1);
pTemp := StrAlloc(w + 1);
F.Read(pTemp^, W);
StrLCopy(pText, pTemp, W);
Caption := StrPas(pText);
StrDispose(pTemp);
StrDispose(pText);
if SubCount > 0 then
begin
for idxSubItem := 1 to SubCount do
begin
F.Read(w, SizeOf(w));
pText := StrAlloc(w + 1);
pTemp := StrAlloc(w + 1);
F.Read(pTemp^, W);
StrLCopy(pText, pTemp, W);
Items[idxItem - 1].SubItems.Add(StrPas(pText));
StrDispose(pTemp);
StrDispose(pText);
end;
end;
end;
end;
F.Free;
end;
end;
// Example:
procedure TForm1.Button1Click(Sender: TObject);
begin
// Save Items and Clear the ListView
SaveListViewToFile(ListView1, 'MyListView.sav');
ListView1.Items.Clear;
end;
procedure TForm1.Button2Click(Sender: TObject);
begin
// Load Items
LoadListViewToFile(ListView1, 'MyListView.sav');
end;

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