Csharp/C Sharp/GUI Windows Form/Open File Dialog

Call ShowDialog() to display an OpenFileDialog

 
using System;
using System.Windows.Forms;
class MainClass {
    static void Main(string[] args) {
        OpenFileDialog dlg = new OpenFileDialog();
        if (dlg.ShowDialog() == DialogResult.OK) {
            Console.WriteLine(dlg.FileName);
        }
    }
}

Demonstrates using an OpenFileDialog to prompt for a file name, and to open a file

/*
C# Programming Tips & Techniques
by Charles Wright, Kris Jamsa
Publisher: Osborne/McGraw-Hill (December 28, 2001)
ISBN: 0072193794
*/
// ReadIn.cs -- Demonstrates using an OpenFileDialog to prompt for a
//              file name, and to open a file
//
//              Compile this program with the following command line:
//                  C:>csc ReadIn.cs
using System;
using System.IO;
using System.Windows.Forms;
namespace nsStreams
{
    
    public class ReadIn
    {
        [STAThread]
        static public void Main (string [] args)
        {
            OpenFileDialog fileOpen = new OpenFileDialog ();
            if (args.Length == 0)
            {
                fileOpen.InitialDirectory = ".\\";
                fileOpen.Filter = "Text files (*.txt)|*.txt|All files (*.*)|*.*";
                fileOpen.FilterIndex = 0;
                fileOpen.RestoreDirectory = false; //true;
//                if (fileOpen.ShowDialog () == DialogResult.Cancel)
                if (fileOpen.ShowDialog () != DialogResult.OK)
                {
                    return;
                }
            }
            else
            {
                fileOpen.FileName = args[0];
            }
            Stream strm;
            StreamReader reader;
            try
            {
                strm = fileOpen.OpenFile ();
                reader = new StreamReader (strm);
            }
            catch (Exception e)
            {
                string Message = e.Message + "\n\nCannot open "
                                 + fileOpen.FileName;
                MessageBox.Show (Message, "Open error",
                                 MessageBoxButtons.OK,
                                 MessageBoxIcon.Error);
                return;
            }
            Console.Write (reader.ReadToEnd ());
            reader.Close ();
            strm.Close ();
        }
    }
}

FileOk Action

 
using System;
using System.IO;
using System.Windows.Forms;
class FileDialogApp {
    private static OpenFileDialog ofd;
    static void Main(string[] args) {
        ofd = new OpenFileDialog();
        string s = Path.GetDirectoryName(Path.GetDirectoryName(Directory.GetCurrentDirectory()));
        ofd.InitialDirectory = s;
        ofd.FileOk += new System.ruponentModel.CancelEventHandler(ofd_OK);
        ofd.ShowDialog();
    }
    public static void ofd_OK(object sender,
        System.ruponentModel.CancelEventArgs e) {
        StreamReader sr = new StreamReader(ofd.FileName);
        string s;
        while ((s = sr.ReadLine()) != null) {
            Console.WriteLine(s);
        }
        sr.Close();
    }
}

Open File Dialog with file types

/*
C# Programming Tips & Techniques
by Charles Wright, Kris Jamsa
Publisher: Osborne/McGraw-Hill (December 28, 2001)
ISBN: 0072193794
*/
namespace nsClassLib
{
    using System;
    using System.IO;
    using System.Windows.Forms;
    
    public class clsMainOpenFileDialog
    {
        [STAThread]
        static public void Main ()
        {
            OpenFileDialog ofn = new OpenFileDialog ();
            ofn.Filter = "C Sharp Files (*.cs)|*.cs|Text Files (*.txt)|*.txt";
            ofn.Title = "Type File";
            while (true)
            {
                if (ofn.ShowDialog () == DialogResult.Cancel)
                    return;
                FileStream strm;
                try
                {
                    strm = new FileStream (ofn.FileName, FileMode.Open, FileAccess.Read);
                    StreamReader rdr = new StreamReader (strm);
                    while (rdr.Peek() >= 0)
                    {
                         string str = rdr.ReadLine ();
                         Console.WriteLine (str);
                    }
                }
                catch (Exception)
                {
                    MessageBox.Show ("Error opening file", "File Error",
                                     MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
                }
                ofn.Title = "Next File to Type";
            }
        }
    }
}

Set Filter

 
using System;
using System.Windows.Forms;
class MainClass {
    static void Main(string[] args) {
        OpenFileDialog dlg = new OpenFileDialog();
        dlg.Filter = "Rich Text Files (*.rtf)|*.RTF|" +
          "All files (*.*)|*.*";
        if (dlg.ShowDialog() == DialogResult.OK) {
            Console.WriteLine(dlg.FileName);
        }
    }
}

Set InitialDirectory

 
using System;
using System.Windows.Forms;
class MainClass {
    static void Main(string[] args) {
        OpenFileDialog dlg = new OpenFileDialog();
        dlg.InitialDirectory = Application.StartupPath;
        if (dlg.ShowDialog() == DialogResult.OK) {
            Console.WriteLine(dlg.FileName);
        }
    }
}

shows browsing for a file

/*
Mastering Visual C# .NET
by Jason Price, Mike Gunderloy
Publisher: Sybex;
ISBN: 0782129110
*/
 /*
  Example15_1.cs shows browsing for a file
*/
using System;
using System.Windows.Forms;
public class Example15_1 {
  
  [STAThread]
  public static void Main() {
    // create and show an open file dialog
  OpenFileDialog dlgOpen = new OpenFileDialog();
  if (dlgOpen.ShowDialog() == DialogResult.OK)
    {
    Console.Write(dlgOpen.FileName);
    }
  }
}

shows browsing for a set of files

/*
Mastering Visual C# .NET
by Jason Price, Mike Gunderloy
Publisher: Sybex;
ISBN: 0782129110
*/

 /*
  Example15_2.cs shows browsing for a set of files
*/
using System;
using System.Windows.Forms;
public class Example15_2 
{
    [STAThread]
  public static void Main() 
  {
    // create an open file dialog
    OpenFileDialog dlgOpen = new OpenFileDialog();
    
    // set properties for the dialog
    dlgOpen.Title = "Select one or more files";
    dlgOpen.ShowReadOnly = true;
    dlgOpen.Multiselect = true;
    // display the dialog and return results
    if (dlgOpen.ShowDialog() == DialogResult.OK)
    {
      foreach (string s in dlgOpen.FileNames)
        Console.WriteLine(s);
    }
  }
}

Show the use of some of the OpenFile dialog box

/*
C# Programming Tips & Techniques
by Charles Wright, Kris Jamsa
Publisher: Osborne/McGraw-Hill (December 28, 2001)
ISBN: 0072193794
*/
// DlgSamp.cs -- Show the use of some of the OpenFile dialog box.
//
//               Compile this program with the following command line:
//                   C:>csc DlgSamp.cs
using System;
using System.Windows.Forms;
using System.ruponentModel;
public class clsMainOpenFile
{
    [STAThread]
    static public void Main ()
    {
// Create the dialog box object.
        OpenFileDialog ofd = new OpenFileDialog ();
// Allow multiple file selection.
        ofd.Multiselect = true;
// Set the text for the title bar.
        ofd.Title = "Concatenate files";
// Do not verify that the file exists.
        ofd.CheckFileExists = false;
// Do verify that the path exists.
        ofd.CheckPathExists = true;
// Add a default extension if the user does not type one.
        ofd.AddExtension = true;
// Set the default extension.
        ofd.DefaultExt = "txt";
// Show the read-only box.
        ofd.ShowReadOnly = true;
// Show the Help button.
        ofd.ShowHelp = true;
// Call this method when the user clicks the OK (Open) button.
        ofd.FileOk += new CancelEventHandler (CancelOpenFile);
// Call this method when the user clicks the Help button.
        ofd.HelpRequest += new EventHandler (ShowOpenHelp);
// Show the dialog box.
        if (ofd.ShowDialog () == DialogResult.Cancel)
            return;
// Display a list of the selected files.
        foreach (string str in ofd.FileNames)
            Console.WriteLine (str);
    }
// Delegate called when the user clicks the OK (Open) button
    static private void CancelOpenFile (object sender, CancelEventArgs e)
    {
// Cast the object to an OpenFileDialog object.
        OpenFileDialog dlg = (OpenFileDialog) sender;
// Show the selected files.
        Console.WriteLine ("The selected file are:");
        foreach (string str in dlg.FileNames)
            Console.WriteLine ("\t" + str);
// Ask whether to cancel the close event.
        Console.Write ("\r\nCancel event? [y/n]: ");
        string reply = Console.ReadLine ();
        if (reply[0] == "y")
            e.Cancel = true;
    }
// Delegate called when the user clicks the Help button.
    static private void ShowOpenHelp (object sender, EventArgs e)
    {
        Console.WriteLine ("Open your help file to the File Open topic here.");
    }
}