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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

	ABA Database Convert
	SMExport suite
	Paradox ActiveX
	ABA Spreadsheet Convert
	SMDBGrid
	Clarion to Text converter
	Excel Reader (dll)
	ABA Document Convert
	ABA Picture Convert
	Excel Web-stream

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