FolderBrowserDialog Constructor

Definition

Namespace:

System.Windows.Forms

Assembly:

System.Windows.Forms.dll

Source:

FolderBrowserDialog.cs

Initializes a new instance of the FolderBrowserDialog class.

C#

public FolderBrowserDialog();

Examples

The following code example creates an application that enables the user to open rich text (.rtf) files within the RichTextBox control.

C#

// The following example displays an application that provides the ability to 
// open rich text files (rtf) into the RichTextBox. The example demonstrates 
// using the FolderBrowserDialog to set the default directory for opening files.
// The OpenFileDialog class is used to open the file.
using System;
using System.Drawing;
using System.Windows.Forms;
using System.IO;

public class FolderBrowserDialogExampleForm : System.Windows.Forms.Form
{
    private FolderBrowserDialog folderBrowserDialog1;
    private OpenFileDialog openFileDialog1;

    private RichTextBox richTextBox1;

    private MenuStrip mainMenu1;
    private ToolStripMenuItem fileMenuItem, openMenuItem;
    private ToolStripMenuItem folderMenuItem, closeMenuItem;

    private string openFileName, folderName;

    private bool fileOpened = false;

    // The main entry point for the application.
    [STAThreadAttribute]
    static void Main()
    {
        Application.Run(new FolderBrowserDialogExampleForm());
    }

    // Constructor.
    public FolderBrowserDialogExampleForm()
    {
        this.mainMenu1 = new MenuStrip();

        this.fileMenuItem = new ToolStripMenuItem();
        this.openMenuItem = new ToolStripMenuItem();
        this.folderMenuItem = new ToolStripMenuItem();
        this.closeMenuItem = new ToolStripMenuItem();

        this.openFileDialog1 = new OpenFileDialog();
        this.folderBrowserDialog1 = new FolderBrowserDialog();
        this.richTextBox1 = new RichTextBox();

        this.mainMenu1.Items.Add(this.fileMenuItem);

        this.fileMenuItem.Text = "File";
        this.fileMenuItem.DropDownItems.AddRange(
            new ToolStripItem[] {
                this.openMenuItem,
                this.closeMenuItem,
                this.folderMenuItem
            }
        );

        this.openMenuItem.Text = "Open...";
        this.openMenuItem.Click += new EventHandler(this.openMenuItem_Click);

        this.folderMenuItem.Text = "Select Directory...";
        this.folderMenuItem.Click += new EventHandler(this.folderMenuItem_Click);

        this.closeMenuItem.Text = "Close";
        this.closeMenuItem.Click += new EventHandler(this.closeMenuItem_Click);
        this.closeMenuItem.Enabled = false;

        this.openFileDialog1.DefaultExt = "rtf";
        this.openFileDialog1.Filter = "rtf files (*.rtf)|*.rtf";

        // Set the help text description for the FolderBrowserDialog.
        this.folderBrowserDialog1.Description =
            "Select the directory that you want to use as the default.";

        // Do not allow the user to create new files via the FolderBrowserDialog.
        this.folderBrowserDialog1.ShowNewFolderButton = false;

        // Default to the My Documents folder.
        this.folderBrowserDialog1.RootFolder = Environment.SpecialFolder.Personal;

        this.richTextBox1.AcceptsTab = true;
        this.richTextBox1.Location = new System.Drawing.Point(8, 40);
        this.richTextBox1.Size = new System.Drawing.Size(280, 312);
        this.richTextBox1.Anchor = (
            AnchorStyles.Top |
            AnchorStyles.Left |
            AnchorStyles.Bottom |
            AnchorStyles.Right
        );

        this.ClientSize = new System.Drawing.Size(296, 360);
        this.Controls.Add(this.mainMenu1);
        this.Controls.Add(this.richTextBox1);
        this.MainMenuStrip = this.mainMenu1;
        this.Text = "RTF Document Browser";
    }

    // Bring up a dialog to open a file.
    private void openMenuItem_Click(object sender, EventArgs e)
    {
        // If a file is not opened, then set the initial directory to the
        // FolderBrowserDialog.SelectedPath value.
        if (!fileOpened) {
            openFileDialog1.InitialDirectory = folderBrowserDialog1.SelectedPath;
            openFileDialog1.FileName = null;
        }

        // Display the openFile dialog.
        DialogResult result = openFileDialog1.ShowDialog();

        // OK button was pressed.
        if (result == DialogResult.OK)
        {
            openFileName = openFileDialog1.FileName;
            try
            {
                // Output the requested file in richTextBox1.
                Stream s = openFileDialog1.OpenFile();
                richTextBox1.LoadFile(s, RichTextBoxStreamType.RichText);
                s.Close();

                fileOpened = true;
            }
            catch (Exception exp)
            {
                MessageBox.Show("An error occurred while attempting to load the file. The error is:"
                                + System.Environment.NewLine + exp.ToString() + System.Environment.NewLine);
                fileOpened = false;
            }
            Invalidate();

            closeMenuItem.Enabled = fileOpened;
        }

        // Cancel button was pressed.
        else if (result == DialogResult.Cancel)
        {
            return;
        }
    }

    // Close the current file.
    private void closeMenuItem_Click(object sender, EventArgs e)
    {
        richTextBox1.Text = "";
        fileOpened = false;

        closeMenuItem.Enabled = false;
    }

    // Bring up a dialog to choose a folder path in which to open or save a file.
    private void folderMenuItem_Click(object sender, EventArgs e)
    {
        // Show the FolderBrowserDialog.
        DialogResult result = folderBrowserDialog1.ShowDialog();
        if (result == DialogResult.OK)
        {
            folderName = folderBrowserDialog1.SelectedPath;
            if (!fileOpened)
            {
                // No file is opened, bring up openFileDialog in selected path.
                openFileDialog1.InitialDirectory = folderName;
                openFileDialog1.FileName = null;
                openMenuItem.PerformClick();
            }
        }
    }
}

Remarks

The parameterless constructor initializes properties to their default values.

When a new FolderBrowserDialog is created, the RootFolder property is set to Environment.SpecialFolder.Desktop, the Description property is set to an empty string (""), the SelectedPath property is set to an empty string, and the ShowNewFolderButton property is set to true.

Typically, after creating a new FolderBrowserDialog, you set the RootFolder to the location from which to start browsing. Optionally, you can set the SelectedPath to the path of a subfolder of RootFolder that will initially be selected. You can also optionally set the Description property to provide additional instructions to the user. Finally, call the ShowDialog method to display the dialog box to the user. When the dialog box is closed and the dialog result from ShowDialog is DialogResult.OK, the SelectedPath will be a string containing the path to the selected folder.

FolderBrowserDialog is a modal dialog box; therefore, when shown, it blocks the rest of the application until the user has chosen a folder. When a dialog box is displayed modally, no input (keyboard or mouse click) can occur except to objects on the dialog box. The program must hide or close the dialog box (usually in response to some user action) before input to the calling program can occur.

Applies to