Drag Drop Problem

[bitsetter]

Hallo,

so müsste es gehen:

Delphi-Quellcode:

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, ExtCtrls;

type
  TListBox = class(StdCtrls.TListBox)
  private
    procedure WMDROPFILES(var Msg: TMessage); Message WM_DROPFILES;
end;

type
  TForm1 = class(TForm)
    ListBox1: TListBox;
    Panel1: TPanel;
    procedure FormCreate(Sender: TObject);
  private

  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

uses
  ShellAPI;

procedure TListBox.WMDROPFILES(var Msg: TMessage);
var
  i, Counts, Size: Integer;
  PCharFileName: PChar;
begin
  inherited;

  PCharFileName := nil;
  Counts := DragQueryFile(Msg.WParam, $FFFFFFFF, PCharFileName, 255);

  for i := 0 to Counts - 1 do
  begin
    Size := DragQueryFile(Msg.WParam, i, nil, 0) + 1;
    PCharFileName := StrAlloc(Size);
    DragQueryFile(Msg.WParam, i, PCharFileName, Size);
    Items.Add(String(PCharFileName));
    StrDispose(PCharFileName);
  end;

  DragFinish(Msg.WParam);
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  DragAcceptFiles(ListBox1.Handle, True);
end;

end.

Du fängst einfach die Nachricht WM_DROPFILES dann von der Listbox ab.

EDIT: mit Subclassing geht es ansonsten auch noch.