Wpf – Open directory dialog

dialogfilesystemswpf

I want the user to select a directory where a file that I will then generate will be saved. I know that in WPF I should use the OpenFileDialog from Win32, but unfortunately the dialog requires file(s) to be selected – it stays open if I simply click OK without choosing one. I could "hack up" the functionality by letting the user pick a file and then strip the path to figure out which directory it belongs to but that's unintuitive at best. Has anyone seen this done before?

Best Answer

You can use the built-in FolderBrowserDialog class for this. Don't mind that it's in the System.Windows.Forms namespace.

using (var dialog = new System.Windows.Forms.FolderBrowserDialog())
{
    System.Windows.Forms.DialogResult result = dialog.ShowDialog();
}

If you want the window to be modal over some WPF window, see the question How to use a FolderBrowserDialog from a WPF application.

EDIT: If you want something a bit more fancy than the plain, ugly Windows Forms FolderBrowserDialog, there are some alternatives that allow you to use the Vista dialog instead:

Third-party libraries, such as Ookii dialogs (.NET 4.5+)

The Windows API Code Pack-Shell:

  using Microsoft.WindowsAPICodePack.Dialogs;

  ...

  var dialog = new CommonOpenFileDialog();
  dialog.IsFolderPicker = true;
  CommonFileDialogResult result = dialog.ShowDialog();

Note that this dialog is not available on operating systems older than Windows Vista, so be sure to check CommonFileDialog.IsPlatformSupported first.

FAT32:

Maximum number of files: 268,173,300
Maximum number of files per directory: 2¹⁶ - 1 (65,535)
Maximum file size: 2 GiB - 1 without LFS, 4 GiB - 1 with

NTFS:

Maximum number of files: 2³² - 1 (4,294,967,295)
Maximum file size
- Implementation: 2⁴⁴ - 2⁶ bytes (16 TiB - 64 KiB)
- Theoretical: 2⁶⁴ - 2⁶ bytes (16 EiB - 64 KiB)
Maximum volume size
- Implementation: 2³² - 1 clusters (256 TiB - 64 KiB)
- Theoretical: 2⁶⁴ - 1 clusters (1 YiB - 64 KiB)

ext2:

Maximum number of files: 10¹⁸
Maximum number of files per directory: ~1.3 × 10²⁰ (performance issues past 10,000)
Maximum file size
- 16 GiB (block size of 1 KiB)
- 256 GiB (block size of 2 KiB)
- 2 TiB (block size of 4 KiB)
- 2 TiB (block size of 8 KiB)
Maximum volume size
- 4 TiB (block size of 1 KiB)
- 8 TiB (block size of 2 KiB)
- 16 TiB (block size of 4 KiB)
- 32 TiB (block size of 8 KiB)

ext3:

Maximum number of files: min(volumeSize / 2¹³, numberOfBlocks)
Maximum file size: same as ext2
Maximum volume size: same as ext2

ext4:

Maximum number of files: 2³² - 1 (4,294,967,295)
Maximum number of files per directory: unlimited
Maximum file size: 2⁴⁴ - 1 bytes (16 TiB - 1)
Maximum volume size: 2⁴⁸ - 1 bytes (256 TiB - 1)

Objective-c – Open File Dialog Box

Thanks @Vlad the Impala I am updating your answers for people who use OS X v10.6+

// Create the File Open Dialog class.
NSOpenPanel* openDlg = [NSOpenPanel openPanel];

// Enable the selection of files in the dialog.
[openDlg setCanChooseFiles:YES];

// Multiple files not allowed
[openDlg setAllowsMultipleSelection:NO];

// Can't select a directory
[openDlg setCanChooseDirectories:NO];

// Display the dialog. If the OK button was pressed,
// process the files.
if ( [openDlg runModal] == NSOKButton )
{
    // Get an array containing the full filenames of all
    // files and directories selected.
    NSArray* urls = [openDlg URLs];

    // Loop through all the files and process them.
    for(int i = 0; i < [urls count]; i++ )
    {
        NSString* url = [urls objectAtIndex:i];
        NSLog(@"Url: %@", url);
    }
}