Accept the Dropped Files From Windows Explorer

Author: Mike Skholnik | Category: System

// If you need accept the dropped files from the some external application (for
// example, from Windows Explorer), you must call the DragAcceptFiles for your
// form (in which you want to accept) and handle the WM_DROPFILES message.
// I used this algoritm when I wrote the small editor.
// I post the next code as simple example: 
 
type
  TForm1 = class(TForm)
    ListBox1: TListBox;
    procedure FormCreate(Sender: TObject);
  protected
    procedure WMDROPFILES (var Msg: TWMDropFiles); message WM_DROPFILES;
  private
  public
  end; 
 
var
  Form1: TForm1; 
 
implementation
uses ShellApi; 
 
{$R *.DFM} 
 
procedure TForm1.FormCreate(Sender: TObject);
begin
  DragAcceptFiles(Handle, True);
end; 
 
procedure TForm1.WMDROPFILES(var Msg: TWMDropFiles);
var
  i, amount: Integer;
  FileName: array[0..MAX_PATH] of Char;
begin
  inherited; 
 
  try
    Amount := DragQueryFile(Msg.Drop, $FFFFFFFF, FileName, MAX_PATH);
    for i := 0 to (Amount - 1) do
    begin
      DragQueryFile(Msg.Drop, i, FileName, MAX_PATH);
      listbox1.items.add(FileName);
    end;
  finally
    DragFinish(Msg.Drop);
  end;
end;

Tags: Explorer, Files