/// <summary>Shows the dialog box to let the user browse for and select a folder.</summary>
/// <param name="parentWindowHandle">The HWND of the parent window.</param>
/// <returns>The selected folder or <c>null</c> if no folder was selected by the user.</returns>
protected override bool RunDialog(IntPtr parentWindowHandle)
{
// Setup BROWSEINFO.dwFlag value
EnumFlagIndexer <BrowseInfoFlag> browseInfoFlag = BrowseInfoFlag.BIF_SHAREABLE;
browseInfoFlag[BrowseInfoFlag.BIF_NEWDIALOGSTYLE] = Application.OleRequired() == ApartmentState.STA;
browseInfoFlag[BrowseInfoFlag.BIF_DONTGOBELOWDOMAIN] = HideDomainFolders;
browseInfoFlag[BrowseInfoFlag.BIF_BROWSEFILEJUNCTIONS] = ShowFileJunctions;
browseInfoFlag[BrowseInfoFlag.BIF_RETURNONLYFSDIRS] = LocalFileSystemOnly;
browseInfoFlag[BrowseInfoFlag.BIF_NONEWFOLDERBUTTON] = !ShowNewFolderButton;
browseInfoFlag[BrowseInfoFlag.BIF_EDITBOX | BrowseInfoFlag.BIF_VALIDATE] = ShowFolderPathEditBox;
switch (BrowseOption)
{
case FolderBrowserDialogOptions.Folders:
break;
case FolderBrowserDialogOptions.FoldersAndFiles:
browseInfoFlag |= BrowseInfoFlag.BIF_BROWSEINCLUDEFILES;
break;
case FolderBrowserDialogOptions.Computers:
browseInfoFlag |= BrowseInfoFlag.BIF_BROWSEFORCOMPUTER;
RootFolder = defaultComputersFolder;
break;
case FolderBrowserDialogOptions.Printers:
browseInfoFlag |= BrowseInfoFlag.BIF_BROWSEFORPRINTER;
RootFolder = defaultPrintersFolder;
break;
default:
throw new ArgumentOutOfRangeException();
}
// Setup the BROWSEINFO structure
var dn = new SafeCoTaskMemString(Kernel32.MAX_PATH);
var bi = new BROWSEINFO(parentWindowHandle, rootPidl.DangerousGetHandle(), Description, browseInfoFlag, OnBrowseEvent, dn.DangerousGetHandle());
// Show the dialog
pidl = SHBrowseForFolder(ref bi);
href = default(HandleRef);
if (pidl.IsInvalid)
{
return(false);
}
if (browseInfoFlag[BrowseInfoFlag.BIF_BROWSEFORPRINTER] || browseInfoFlag[BrowseInfoFlag.BIF_BROWSEFORCOMPUTER])
{
SelectedItem = bi.DisplayName;
}
else
{
SelectedItem = GetNameForPidl(pidl);
}
return(true);
}
/// <summary>Callback for Windows.</summary>
/// <param name="hwnd">Window handle of the browse dialog box.</param>
/// <param name="uMsg">Dialog box event that generated the statusMessage.</param>
/// <param name="lParam">Value whose meaning depends on the event specified in uMsg.</param>
/// <param name="lpData">Application-defined value that was specified in the lParam member of the BROWSEINFO structure used in the call to SHBrowseForFolder.</param>
/// <returns>
/// Returns 0 except in the case of BFFM_VALIDATEFAILED. For that flag, returns 0 to dismiss the dialog or nonzero to keep the dialog displayed.
/// </returns>
//[CLSCompliant(false)]
private int OnBrowseEvent(IntPtr hwnd, BrowseForFolderMessages uMsg, IntPtr lParam, IntPtr lpData)
{
var messsage = uMsg;
href = new HandleRef(this, hwnd);
switch (messsage)
{
case BrowseForFolderMessages.BFFM_INITIALIZED:
// Dialog is being initialized, so set the initial parameters
if (!string.IsNullOrEmpty(Caption))
{
SetWindowText(href, Caption);
}
if (!string.IsNullOrEmpty(SelectedItem))
{
SendMessage(href, (uint)BrowseForFolderMessages.BFFM_SETSELECTIONW, (IntPtr)1, SelectedItem);
}
if (Expanded)
{
SendMessage(href, (uint)BrowseForFolderMessages.BFFM_SETEXPANDED, (IntPtr)1, rootPidl.DangerousGetHandle());
}
if (!string.IsNullOrEmpty(OkText))
{
SendMessage(href, (uint)BrowseForFolderMessages.BFFM_SETOKTEXT, (IntPtr)0, OkText);
}
Initialized?.Invoke(this, new FolderBrowserDialogInitializedEventArgs(hwnd));
initialized = true;
return(0);
case BrowseForFolderMessages.BFFM_SELCHANGED:
try
{
if (!initialized || pidl?.DangerousGetHandle() == lParam)
{
return(0);
}
var tmpPidl = new PIDL(lParam, false, false);
var str = GetNameForPidl(tmpPidl);
if (string.IsNullOrEmpty(str))
{
return(0);
}
SelectedItem = str;
pidl = tmpPidl;
}
catch
{
return(0);
}
SelectedItemChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(SelectedItem)));
return(0);
case BrowseForFolderMessages.BFFM_VALIDATEFAILEDA:
case BrowseForFolderMessages.BFFM_VALIDATEFAILEDW:
if (InvalidFolderSelected != null)
{
var folderName = messsage == BrowseForFolderMessages.BFFM_VALIDATEFAILEDA ? Marshal.PtrToStringAnsi(lParam) : Marshal.PtrToStringUni(lParam);
var e = new InvalidFolderEventArgs(folderName, true);
InvalidFolderSelected?.Invoke(this, e);
return(e.DismissDialog ? 0 : 1);
}
return(0);
default:
return(0);
}
}