Can I launch DotNet's OpenFileDialog in C:\Users\Public\Documents?

Question

Is there a way to launch the OpenFileDialog in the C:\Users\Public\Documents folder?

I am writing a C# application, using the DotNet framework. I am trying to launch an OpenFileDialog, with an InitialDirectory of "C:\\Users\\Public\\Documents\\" and a FileName of "world.txt". Unfortunately, the OpenFileDialog is putting me in the Documents shortcut instead of into C:\Users\Public\Documents .

Expected results
I expect to see the OpenFileDialog open, with the top textbox showing > This PC > Windows7_OS (C:) > Users > Public > Documents and the bottom textbox showing world.txt . I expect that if I click in the top textbox, it will show C:\Users\Public\Documents .

Actual results
The OpenFileDialog opens. The top textbox shows > This PC > Documents and the bottom textbox shows world.txt . If I click in the top textbox, it shows Documents . The displayed folder contents are not the same as the contents of C:\Users\Public\Documents .

Things I have tried
I have stopped the code in the Visual Studio debugger after the following line of code:
OpenFileDialog dlg = new OpenFileDialog();

In the Immediate Window, I have executed code such as the following:

dlg.FileName = "world.txt"  
? dlg.FileName  
dlg.InitialDirectory = "C:\\NonExistentDirectory\\";  
dlg.ShowDialog();  
dlg.InitialDirectory = "C:\\";  
dlg.ShowDialog();  
dlg.InitialDirectory = "C:\\Users\\";  
dlg.ShowDialog(); 
dlg.InitialDirectory = "C:\\Users\\Public\\";  
dlg.ShowDialog(); 
dlg.InitialDirectory = "C:\\Users\\Public\\Documents\\";  
dlg.ShowDialog();  

I cancel out of each dialog.

I used C:\WINDOWS\System32\cmd.exe to cd between C:\ and C:\Users\ and C:\Users\Public and C:\Users\Public\Documents\ .

Results of things I have tried

• When dlg.InitialDirectory = "C:\\NonExistentDirectory\\" , the dialog's folder initially displays as This PC > Documents > Visual Studio 2015 > Projects > SimpleGame > Controller > bin > Debug" . Clicking in the textbox causes it to display C:\Users\Owner\Documents\Visual Studio 2015\Projects\SimpleGame\Controller\bin\Debug . I therefore assume that OpenFileDialog silently handles an invalid InitialDirectory by not changing directories. In this case, it is defaulting to my project's assembly's bin's Debug folder.

• When dlg.InitialDirectory is "C:\\" or "C:\\Users\\" or "C:\\Users\\Public\\" the dialog behaves as expected. Clicking in the top textbox produces C:\ or C:\Users or C:\Users\Public respectively.

• When dlg.InitialDirectory = "C:\\Users\\Public\\Documents\\" the dialog behaves incorrectly. The top textbox shows > This PC > Documents and the bottom textbox shows world.txt . If I click in the top textbox, it shows Documents . The displayed folder contents are not the same as the contents of C:\Users\Public\Documents .

• Using cmd.exe lets me cd between the folders as expected, including into C:\Users\Public\Documents .

My environment
I am running Microsoft Visual Studio Community 2015 Version 14.0.23107.0 D14REL, using Microsoft Visual C# 2015. My operating system is Windows 10 Pro.

Answer 1

although as stated by Silver, this is a bug but can be roughly bypassed using SendMessage API with WM_SETTEXT on a different thread although hackish to say the least, it will most likely work.

i've put together some dirty code snippet using NSGaga's post to show a proof of concept, this raw example should not be used as is.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading;
using System.Windows.Forms;

namespace WindowsFormsApplication13
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            OpenFileDialog dlg = new OpenFileDialog();

            //start a thread to change the dialog path just before displaying it to the user
            Thread posThread = new Thread(setDialogPath);
            posThread.Start();

            //display dialog to the user
            DialogResult dr = dlg.ShowDialog();
        }

        [DllImport("user32.dll")]
        static extern IntPtr FindWindow(IntPtr lpClassName, string lpWindowName);
        [DllImport("user32.dll")]
        static extern IntPtr SendMessage(IntPtr hWnd, int Msg, int wParam, string lParam);
        [DllImport("user32.dll")]
        static extern IntPtr PostMessage(IntPtr hWnd, int Msg, int wParam, int lParam);
        [DllImport("user32.Dll")]
        [return: MarshalAs(UnmanagedType.Bool)]
        static extern bool EnumChildWindows(IntPtr parentHandle, Win32Callback callback, IntPtr lParam);
        [DllImport("user32.dll", CharSet = CharSet.Auto)]
        static extern IntPtr GetClassName(IntPtr hWnd, System.Text.StringBuilder lpClassName, int nMaxCount);

        private void setDialogPath()
        {
            const string FULL_PATH = "C:\\Users\\Public\\Documents";

            //messages
            const int WM_SETTEXT = 0xC;
            const int WM_KEYDOWN = 0x100;
            const int WM_KEYUP = 0x101;
            //enter key code
            const int VK_RETURN = 0x0D;

            //dialog box window handle
            IntPtr _window_hwnd;

            //how many attempts to detect the window
            int _attempts_count = 0;

            //get the dialog window handle
            while ((_window_hwnd = FindWindow(IntPtr.Zero, "Open")) == IntPtr.Zero)
                if (++_attempts_count > 100)
                    return;
                else
                    Thread.Sleep(500); //try again

            //in it - find the path textbox's handle.
            var hwndChild = EnumAllWindows(_window_hwnd, "Edit").FirstOrDefault();

            //set the path
            SendMessage(hwndChild, WM_SETTEXT, 0, FULL_PATH);

            //apply the path (send 'enter' to the textbox)
            PostMessage(hwndChild, WM_KEYDOWN, VK_RETURN, 0);
            PostMessage(hwndChild, WM_KEYUP, VK_RETURN, 0);
        }


        public delegate bool Win32Callback(IntPtr hwnd, IntPtr lParam);

        private static bool EnumWindow(IntPtr handle, IntPtr pointer)
        {
            GCHandle gch = GCHandle.FromIntPtr(pointer);
            List<IntPtr> list = gch.Target as List<IntPtr>;
            if (list == null)
                throw new InvalidCastException("GCHandle Target could not be cast as List<IntPtr>");
            list.Add(handle);
            return true;
        }

        public static List<IntPtr> GetChildWindows(IntPtr parent)
        {
            List<IntPtr> result = new List<IntPtr>();
            GCHandle listHandle = GCHandle.Alloc(result);
            try
            {
                Win32Callback childProc = new Win32Callback(EnumWindow);
                EnumChildWindows(parent, childProc, GCHandle.ToIntPtr(listHandle));
            }
            finally
            {
                if (listHandle.IsAllocated)
                    listHandle.Free();
            }
            return result;
        }

        public static string GetWinClass(IntPtr hwnd)
        {
            if (hwnd == IntPtr.Zero)
                return null;
            StringBuilder classname = new StringBuilder(100);
            IntPtr result = GetClassName(hwnd, classname, classname.Capacity);
            if (result != IntPtr.Zero)
                return classname.ToString();
            return null;
        }

        public static IEnumerable<IntPtr> EnumAllWindows(IntPtr hwnd, string childClassName)
        {
            List<IntPtr> children = GetChildWindows(hwnd);
            if (children == null)
                yield break;
            foreach (IntPtr child in children)
            {
                if (GetWinClass(child) == childClassName)
                    yield return child;
                foreach (var childchild in EnumAllWindows(child, childClassName))
                    yield return childchild;
            }
        }

    }
}

Hackish, but doable

Answer 2

If you are using System.Windows.Forms.OpenFileDialog you can set:

dialog.AutoUpgradeEnabled = false;

The dialog will look a little dated/flat/"old school" but it does at least display the correct contents!