/// <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, uint uMsg, IntPtr lParam, IntPtr lpData) { BrowseForFolderMessages messsage = (BrowseForFolderMessages)uMsg; switch (messsage) { case BrowseForFolderMessages.BFFM_INITIALIZED: // Dialog is being initialized, so set the initial parameters if (!String.IsNullOrEmpty(Caption)) { NativeMethods.SetWindowText(hwnd, Caption); } if (!String.IsNullOrEmpty(SelectedPath)) { NativeMethods.SendMessage(hwnd, (uint)BrowseForFolderMessages.BFFM_SETEXPANDED, (IntPtr)1, SelectedPath); NativeMethods.SendMessage(hwnd, (uint)BrowseForFolderMessages.BFFM_SETSELECTIONW, (IntPtr)1, SelectedPath); } if (!String.IsNullOrEmpty(OkText)) { NativeMethods.SendMessage(hwnd, (uint)BrowseForFolderMessages.BFFM_SETOKTEXT, (IntPtr)0, OkText); } if (Initialized != null) { EventHandler <FolderBrowserDialogInitializedEventArgs> h = Initialized; h(this, new FolderBrowserDialogInitializedEventArgs(hwnd)); } return(0); case BrowseForFolderMessages.BFFM_SELCHANGED: try { StringBuilder sb = new StringBuilder(260); if (lParam == IntPtr.Zero || 0 == NativeMethods.SHGetPathFromIDList(lParam, sb)) { return(0); } SelectedPath = sb.ToString(); } catch { return(0); } if (SelectedPathChanged != null) { PropertyChangedEventHandler h = SelectedPathChanged; h(this, new PropertyChangedEventArgs("SelectedPath")); } return(0); case BrowseForFolderMessages.BFFM_VALIDATEFAILEDA: case BrowseForFolderMessages.BFFM_VALIDATEFAILEDW: if (InvalidFolderSelected != null) { string folderName; if (messsage == BrowseForFolderMessages.BFFM_VALIDATEFAILEDA) { folderName = Marshal.PtrToStringAnsi(lParam); } else { folderName = Marshal.PtrToStringUni(lParam); } EventHandler <InvalidFolderEventArgs> h = InvalidFolderSelected; InvalidFolderEventArgs e = new InvalidFolderEventArgs(folderName, true); h(this, e); return(e.DismissDialog ? 0 : 1); } return(0); default: return(0); } }
/// <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) { // Make sure OLE is initialized. This is a prerequisite for calling SHBrowseForFolder. NativeMethods.OleInitialize(IntPtr.Zero); IntPtr rpidl = IntPtr.Zero; NativeMethods.SHGetSpecialFolderLocation(parentWindowHandle, (int)RootFolder, out rpidl); if (rpidl == IntPtr.Zero) { NativeMethods.SHGetSpecialFolderLocation(parentWindowHandle, 0, out rpidl); if (rpidl == IntPtr.Zero) { throw new InvalidOperationException("No root folder specified for FolderBrowserDialog2."); } } if (Control.CheckForIllegalCrossThreadCalls && (Application.OleRequired() != System.Threading.ApartmentState.STA)) { throw new System.Threading.ThreadStateException("Debugging Exception Only. Thread must be STA."); } BrowseInfoFlag browseInfoFlag = BrowseInfoFlag.BIF_NEWDIALOGSTYLE | BrowseInfoFlag.BIF_SHAREABLE; if (!ShowNewFolderButton) { browseInfoFlag |= BrowseInfoFlag.BIF_NONEWFOLDERBUTTON; } if (ShowFolderPathEditBox) { browseInfoFlag |= BrowseInfoFlag.BIF_EDITBOX | BrowseInfoFlag.BIF_VALIDATE; } if (ShowFiles) { browseInfoFlag |= BrowseInfoFlag.BIF_BROWSEINCLUDEFILES; } browseInfoFlag |= (BrowseInfoFlag)BrowserFlag; NativeMethods.BROWSEINFO bi; bi.hwndOwner = parentWindowHandle; bi.pidlRoot = rpidl; bi.pszDisplayName = new string('\0', 260); bi.lpszTitle = Description; bi.ulFlags = (uint)browseInfoFlag; bi.lpfn = new NativeMethods.BrowseCallBackProc(OnBrowseEvent); bi.lParam = IntPtr.Zero; bi.iImage = 0; StringBuilder sb = new StringBuilder(260); IntPtr pidl = IntPtr.Zero; try { pidl = NativeMethods.SHBrowseForFolder(ref bi); if (((browseInfoFlag & BrowseInfoFlag.BIF_BROWSEFORPRINTER) == BrowseInfoFlag.BIF_BROWSEFORPRINTER) || ((browseInfoFlag & BrowseInfoFlag.BIF_BROWSEFORCOMPUTER) == BrowseInfoFlag.BIF_BROWSEFORCOMPUTER)) { SelectedPath = bi.pszDisplayName; } else { if (pidl == IntPtr.Zero || 0 == NativeMethods.SHGetPathFromIDList(pidl, sb)) { return(false); } SelectedPath = sb.ToString(); } return(true); } finally { if (rpidl != IntPtr.Zero) { Marshal.FreeCoTaskMem(rpidl); } if (pidl != IntPtr.Zero) { Marshal.FreeCoTaskMem(pidl); } } }