open multiple files via shell context menu as params - file

Question

I want to select more than one text file in the windows explorer and open the files via context menu in my app. For one file I found the solution but for more files there some ideas but no (working) solutions.
Anyone here that has the answer?

Answer 1

Here is an example that i've just searched and collected from internet.
Aim: Select multiple folders in Windows Explorer and get list of these folders' names via a shell context menu item "SelectedFolders", or using SendTo menu or drag-and-drop folders from shell onto the application form.
Please put a listbox named lstSelectedFolders and a speed button named sbClearList.
The main form name is frmSelectedFolders.
Here we go.
/////////////////////////////////////////////////////////////
program selectedfolders;
uses
Windows, Messages, SysUtils, Forms,
uSelectedFolders in 'uSelectedFolders.pas' {frmSelectedFolders};
{$R *.res}
var
receiver: THandle;
i, result: integer;
s: string;
dataToSend: TCopyDataStruct;
Mutex : THandle;
begin
Mutex := CreateMutex(nil, True, 'SelectedFolders');
if (Mutex <> 0) and (GetLastError = 0) then
begin
Application.Initialize;
Application.Title := 'Selected Folders';
Application.CreateForm(TfrmSelectedFolders, frmSelectedFolders);
Application.Run;
if Mutex <> 0 then CloseHandle(Mutex);
end
else
begin
receiver := FindWindow(PChar('TfrmSelectedFolders'), PChar('Selected Folders'));
if receiver <> 0 then
begin
for i:=1 to ParamCount do
begin
s := trim(ParamStr(i));
if s <> '' then
begin
dataToSend.dwData := 0;
dataToSend.cbData := 1 + Length(s);
dataToSend.lpData := PChar(s);
result := SendMessage(receiver, WM_COPYDATA, Integer(Application.Handle), Integer(#dataToSend));
//sleep(100);
//if result > 0 then
// ShowMessage(Format('Sender side: Receiver has %d items in list!', [result]));
end;
end; // for i
end;
end;
end.
/////////////////////////////////////////////////////////////
unit uSelectedFolders;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, ShellAPI, ActiveX, ComObj, ShlObj, Registry, Buttons;
type
TfrmSelectedFolders = class(TForm)
lstSelectedFolders: TListBox;
sbClearList: TSpeedButton;
procedure FormCreate(Sender: TObject);
procedure sbClearListClick(Sender: TObject);
private { Private declarations }
public { Public declarations }
procedure WMDROPFILES(var Message: TWMDROPFILES); message WM_DROPFILES;
procedure WMCopyData(var Msg: TWMCopyData); message WM_COPYDATA;
function GetTarget(const LinkFileName: string): string;
end;
var
frmSelectedFolders: TfrmSelectedFolders;
implementation
{$R *.dfm}
procedure RegisterContextMenuForFolders();
const
Key = 'Directory\shell\SelectedFolders\command\';
begin
with TRegistry.Create do
try
// for all users, class registration for directories
RootKey := HKEY_CLASSES_ROOT;
if OpenKey(Key, true) then
WriteString('', '"' + Application.ExeName + '" "%l"');
finally
Free;
end;
end;
procedure TfrmSelectedFolders.WMDROPFILES(var Message: TWMDROPFILES);
var
N, i: integer;
buffer: array[0..255] of Char;
s: string;
begin
try
N := DragQueryFile(Message.Drop, $FFFFFFFF, nil, 0);
for i:=1 to N do
begin
DragQueryFile(Message.Drop, i-1, #buffer, SizeOf(buffer));
s := buffer;
if UpperCase(ExtractFileExt(s)) = '.LNK' then
s := GetTarget(s);
if lstSelectedFolders.Items.IndexOf(s) < 0 then
lstSelectedFolders.Items.Add(s);
end;
finally
DragFinish(Message.Drop);
end;
end;
function TfrmSelectedFolders.GetTarget(const LinkFileName: string): string;
var
//Link : String;
psl : IShellLink;
ppf : IPersistFile;
WidePath : Array[0..260] of WideChar;
Info : Array[0..MAX_PATH] of Char;
wfs : TWin32FindData;
begin
if UpperCase(ExtractFileExt(LinkFileName)) <> '.LNK' then
begin
Result := 'NOT a shortuct by extension!';
Exit;
end;
CoCreateInstance(CLSID_ShellLink, nil, CLSCTX_INPROC_SERVER, IShellLink, psl);
if psl.QueryInterface(IPersistFile, ppf) = 0 Then
Begin
MultiByteToWideChar(CP_ACP, MB_PRECOMPOSED, PChar(LinkFileName), -1, #WidePath, MAX_PATH);
ppf.Load(WidePath, STGM_READ);
psl.GetPath(#info, MAX_PATH, wfs, SLGP_UNCPRIORITY);
Result := info;
end
else
Result := '';
end;
procedure TfrmSelectedFolders.WMCopyData(var Msg: TWMCopyData);
var
s: string;
begin
s := trim(PChar(Msg.copyDataStruct.lpData));
if s = '' then
begin
msg.Result := -1;
exit;
end;
if UpperCase(ExtractFileExt(s)) = '.LNK' then
s := GetTarget(s);
if lstSelectedFolders.Items.IndexOf(s) < 0 then
lstSelectedFolders.Items.Add(s);
msg.Result := lstSelectedFolders.Items.Count;
end;
procedure TfrmSelectedFolders.FormCreate(Sender: TObject);
var
i: integer;
s: string;
begin
RegisterContextMenuForFolders();
DragAcceptFiles(Handle, TRUE);
lstSelectedFolders.Clear;
s := ExtractFileDir(Application.ExeName);
lstSelectedFolders.Items.Add(s);
for i:=1 to ParamCount do
begin
s := trim(ParamStr(i));
if UpperCase(ExtractFileExt(s)) = '.LNK' then
s := GetTarget(s);
if lstSelectedFolders.Items.IndexOf(s) < 0 then
lstSelectedFolders.Items.Add(s);
end;
end;
procedure TfrmSelectedFolders.sbClearListClick(Sender: TObject);
begin
lstSelectedFolders.Clear;
end;
end.