unit dbgdMain;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, DBGridEhGrouping, ToolCtrlsEh, DBGridEhToolCtrls, DynVarsEh, EhLibVCL, GridsEh,
  DBAxisGridsEh, DBGridEh;

type
  TDropFilesEvent = procedure (Sender: TObject; DropHandle: THandle) of object;

  TDBGridEh = class(DBGridEh.TDBGridEh)
  strict private
    FAcceptDroppedFiles: Boolean;
    FOnDropFiles: TDropFilesEvent;
    procedure SetAcceptDroppedFiles(const Value: Boolean);
  protected
    procedure WMDropFiles(var Message: TWMDropFiles); message WM_DROPFILES;
    procedure CreateWnd; override;
  public
    property AcceptDroppedFiles: Boolean read FAcceptDroppedFiles write SetAcceptDroppedFiles;
    property OnDropFiles: TDropFilesEvent read FOnDropFiles write FOnDropFiles;
  end;

  TForm1 = class(TForm)
    DBGridEh1: TDBGridEh;
    DBGridEh2: TDBGridEh;
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    procedure DBGridEh2FilesDropped(Sender: TObject; DropHandle: THandle);
  end;

var
  Form1: TForm1;

implementation

uses
  Winapi.ShellAPI;

{$R *.dfm}

{ TDBGridEh }

procedure TDBGridEh.CreateWnd;
begin
  inherited;
  if AcceptDroppedFiles then
    DragAcceptFiles(Handle, TRUE);
end;

procedure TDBGridEh.SetAcceptDroppedFiles(const Value: Boolean);
begin
  if FAcceptDroppedFiles <> Value then
  begin
    FAcceptDroppedFiles := Value;
    if HandleAllocated then
      DragAcceptFiles(Handle, Value);
  end;
end;

procedure TDBGridEh.WMDropFiles(var Message: TWMDropFiles);
begin
  if Assigned(FOnDropFiles) then
    FOnDropFiles(Self, Message.Drop);
end;

{ TForm1 }

procedure TForm1.DBGridEh2FilesDropped(Sender: TObject; DropHandle: THandle);
var
  Count: Integer;
begin
  Count := DragQueryFile(DropHandle, $FFFFFFFF, nil, 0);
  ShowMessage(Format('%d файлов принято!', [Count]));
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  DBGridEh2.AcceptDroppedFiles := True;
  DBGridEh2.OnDropFiles := DBGridEh2FilesDropped;
end;

end.