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Пример загрузки файлов в ListView с иконками



Автор: Song

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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