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#157: Select folder dialog

Yesterday I posted how to display standard dialog for files (open/save). Today I want to show how you may use stamndard dialog when user must select a folder/directory.

Use the next function:

uses SysUtils, ShlObj;

function BrowseCallbackProc(hwnd: HWND; uMsg: UINT; lParam: LPARAM; lpData: LPARAM): Integer; stdcall;
begin
  if (uMsg = BFFM_INITIALIZED) then
    SendMessage(hwnd, BFFM_SETSELECTION, 1, lpData);
  BrowseCallbackProc := 0;
end;

function GetFolderDialog(Handle: Integer; Caption: string; var strFolder: string): Boolean;
const
  BIF_STATUSTEXT           = $0004;
  BIF_NEWDIALOGSTYLE       = $0040;
  BIF_RETURNONLYFSDIRS     = $0080;
  BIF_SHAREABLE            = $0100;
  BIF_USENEWUI             = BIF_EDITBOX or BIF_NEWDIALOGSTYLE;

var
  BrowseInfo: TBrowseInfo;
  ItemIDList: PItemIDList;
  JtemIDList: PItemIDList;
  Path: PAnsiChar;
begin
  Result := False;
  Path := StrAlloc(MAX_PATH);
  SHGetSpecialFolderLocation(Handle, CSIDL_DRIVES, JtemIDList);
  with BrowseInfo do
  begin
    hwndOwner := GetActiveWindow;
    pidlRoot := JtemIDList;
    SHGetSpecialFolderLocation(hwndOwner, CSIDL_DRIVES, JtemIDList);

    { return display name of item selected }
    pszDisplayName := StrAlloc(MAX_PATH);

    { set the title of dialog }
    lpszTitle := PChar(Caption);//'Select the folder';
    { flags that control the return stuff }
    lpfn := @BrowseCallbackProc;
    { extra info that's passed back in callbacks }
    lParam := LongInt(PChar(strFolder));
  end;

  ItemIDList := SHBrowseForFolder(BrowseInfo);

  if (ItemIDList <> nil) then
    if SHGetPathFromIDList(ItemIDList, Path) then
    begin
      strFolder := Path;
      Result := True
    end;
end;

For example,

s := 'c:\Arch';
if GetFolderDialog(Application.Handle, 'Select a folder', s) then
  ShowMessage('User selected this folder: ' + s)

Published: October 2, 2003

See also

	Fast Document Viewer
	SMExport suite
	MAPIMail
	ABA Picture Convert
	Viewer for TNEF-files (winmail.dat)
	Excel Reader (dll)
	ExcelFile Viewer
	SMImport suite
	Protected Storage Viewer
	ABA Document Convert

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