FolderBrowserDialog Конструктор

Определение

Инициализирует новый экземпляр класса FolderBrowserDialog.

public:
 FolderBrowserDialog();
public FolderBrowserDialog ();
Public Sub New ()

Примеры

В следующем примере кода создается приложение, которое позволяет пользователю открывать rtf-файлы в элементе RichTextBox управления .

// 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 is used to open the file.
#using <System.dll>
#using <System.Windows.Forms.dll>
#using <System.Drawing.dll>

using namespace System;
using namespace System::Drawing;
using namespace System::Windows::Forms;
using namespace System::IO;
public ref class FolderBrowserDialogExampleForm: public System::Windows::Forms::Form
{
private:
   FolderBrowserDialog^ folderBrowserDialog1;
   OpenFileDialog^ openFileDialog1;
   RichTextBox^ richTextBox1;
   MainMenu^ mainMenu1;
   MenuItem^ fileMenuItem;
   MenuItem^ openMenuItem;
   MenuItem^ folderMenuItem;
   MenuItem^ closeMenuItem;
   String^ openFileName;
   String^ folderName;
   bool fileOpened;

public:

   // Constructor.
   FolderBrowserDialogExampleForm()
   {
      fileOpened = false;
      this->mainMenu1 = gcnew System::Windows::Forms::MainMenu;
      this->fileMenuItem = gcnew System::Windows::Forms::MenuItem;
      this->openMenuItem = gcnew System::Windows::Forms::MenuItem;
      this->folderMenuItem = gcnew System::Windows::Forms::MenuItem;
      this->closeMenuItem = gcnew System::Windows::Forms::MenuItem;
      this->openFileDialog1 = gcnew System::Windows::Forms::OpenFileDialog;
      this->folderBrowserDialog1 = gcnew System::Windows::Forms::FolderBrowserDialog;
      this->richTextBox1 = gcnew System::Windows::Forms::RichTextBox;
      this->mainMenu1->MenuItems->Add( this->fileMenuItem );
      array<System::Windows::Forms::MenuItem^>^temp0 = {this->openMenuItem,this->closeMenuItem,this->folderMenuItem};
      this->fileMenuItem->MenuItems->AddRange( temp0 );
      this->fileMenuItem->Text = "File";
      this->openMenuItem->Text = "Open...";
      this->openMenuItem->Click += gcnew System::EventHandler( this, &FolderBrowserDialogExampleForm::openMenuItem_Click );
      this->folderMenuItem->Text = "Select Directory...";
      this->folderMenuItem->Click += gcnew System::EventHandler( this, &FolderBrowserDialogExampleForm::folderMenuItem_Click );
      this->closeMenuItem->Text = "Close";
      this->closeMenuItem->Click += gcnew System::EventHandler( this, &FolderBrowserDialogExampleForm::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 = System::Drawing::Point( 8, 8 );
      this->richTextBox1->Size = System::Drawing::Size( 280, 344 );
      this->richTextBox1->Anchor = static_cast<AnchorStyles>(AnchorStyles::Top | AnchorStyles::Left | AnchorStyles::Bottom | AnchorStyles::Right);
      this->ClientSize = System::Drawing::Size( 296, 360 );
      this->Controls->Add( this->richTextBox1 );
      this->Menu = this->mainMenu1;
      this->Text = "RTF Document Browser";
   }


private:

   // Bring up a dialog to open a file.
   void openMenuItem_Click( Object^ /*sender*/, System::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 = nullptr;
      }

      
      // Display the openFile Dialog.
      System::Windows::Forms::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( String::Concat( "An error occurred while attempting to load the file. The error is: ", System::Environment::NewLine, exp, System::Environment::NewLine ) );
            fileOpened = false;
         }

         Invalidate();
         closeMenuItem->Enabled = fileOpened;
      }
      // Cancel button was pressed.
      else
      
      // Cancel button was pressed.
      if ( result == ::DialogResult::Cancel )
      {
         return;
      }
   }


   // Close the current file.
   void closeMenuItem_Click( Object^ /*sender*/, System::EventArgs^ /*e*/ )
   {
      richTextBox1->Text = "";
      fileOpened = false;
      closeMenuItem->Enabled = false;
   }


   // Bring up a dialog to chose a folder path in which to open/save a file.
   void folderMenuItem_Click( Object^ /*sender*/, System::EventArgs^ /*e*/ )
   {
      
      // Show the FolderBrowserDialog.
      System::Windows::Forms::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 = nullptr;
            openMenuItem->PerformClick();
         }
      }
   }

};


// The main entry point for the application.
int main()
{
   Application::Run( gcnew FolderBrowserDialogExampleForm );
}
// 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();
            }
        }
    }
}
' 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.
Imports System.Drawing
Imports System.Windows.Forms
Imports System.IO

Public Class FolderBrowserDialogExampleForm 
    Inherits Form
    
    Private folderBrowserDialog1 As FolderBrowserDialog
    Private openFileDialog1 As OpenFileDialog 
    
    Private richTextBox1 As RichTextBox

    Private mainMenu1 As MainMenu
    Private fileMenuItem As MenuItem
    Private WithEvents folderMenuItem As MenuItem, _
                       closeMenuItem As MenuItem, _
                       openMenuItem As MenuItem
    
    Private openFileName As String, folderName As String

    Private fileOpened As Boolean = False

    Public Sub New()
        Me.mainMenu1 = New System.Windows.Forms.MainMenu() 
        Me.fileMenuItem = New System.Windows.Forms.MenuItem() 
        Me.openMenuItem = New System.Windows.Forms.MenuItem() 
        Me.folderMenuItem = New System.Windows.Forms.MenuItem() 
        Me.closeMenuItem = New System.Windows.Forms.MenuItem() 

        Me.openFileDialog1 = New System.Windows.Forms.OpenFileDialog() 
        Me.folderBrowserDialog1 = New System.Windows.Forms.FolderBrowserDialog() 
        Me.richTextBox1 = New System.Windows.Forms.RichTextBox() 

        Me.mainMenu1.MenuItems.Add(Me.fileMenuItem) 
        Me.fileMenuItem.MenuItems.AddRange( _
                    New System.Windows.Forms.MenuItem() {Me.openMenuItem, _
                                                         Me.closeMenuItem, _
                                                         Me.folderMenuItem}) 
        Me.fileMenuItem.Text = "File" 

        Me.openMenuItem.Text = "Open..." 

        Me.folderMenuItem.Text = "Select Directory..." 

        Me.closeMenuItem.Text = "Close" 
        Me.closeMenuItem.Enabled = False 

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

        ' Set the Help text description for the FolderBrowserDialog.
        Me.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.
        Me.folderBrowserDialog1.ShowNewFolderButton = False 

        ' Default to the My Documents folder.
        Me.folderBrowserDialog1.RootFolder = Environment.SpecialFolder.Personal 

        Me.richTextBox1.AcceptsTab = True 
        Me.richTextBox1.Location = New System.Drawing.Point(8, 8) 
        Me.richTextBox1.Size = New System.Drawing.Size(280, 344) 
        Me.richTextBox1.Anchor = AnchorStyles.Top Or AnchorStyles.Left Or _
                                 AnchorStyles.Bottom Or AnchorStyles.Right 

        Me.ClientSize = New System.Drawing.Size(296, 360) 
        Me.Controls.Add(Me.richTextBox1) 
        Me.Menu = Me.mainMenu1 
        Me.Text = "RTF Document Browser" 
    End Sub
    
    <STAThread()> _
    Shared Sub Main()
        Application.Run(New FolderBrowserDialogExampleForm())
    End Sub

    ' Bring up a dialog to open a file.
    Private Sub openMenuItem_Click(sender As object, e As System.EventArgs) _
        Handles openMenuItem.Click
        ' If a file is not opened, then set the initial directory to the
        ' FolderBrowserDialog.SelectedPath value.
        If (not fileOpened) Then
            openFileDialog1.InitialDirectory = folderBrowserDialog1.SelectedPath 
            openFileDialog1.FileName = nothing 
        End If

        ' Display the openFile dialog.
        Dim result As DialogResult = openFileDialog1.ShowDialog() 

        ' OK button was pressed.
        If (result = DialogResult.OK) Then
            openFileName = openFileDialog1.FileName 
            Try
                ' Output the requested file in richTextBox1.
                Dim s As Stream = openFileDialog1.OpenFile() 
                richTextBox1.LoadFile(s, RichTextBoxStreamType.RichText) 
                s.Close()     
            
                fileOpened = True 

            Catch exp As Exception
                MessageBox.Show("An error occurred while attempting to load the file. The error is:" _
                                + System.Environment.NewLine + exp.ToString() + System.Environment.NewLine) 
                fileOpened = False 
            End Try
            Invalidate() 

            closeMenuItem.Enabled = fileOpened 

        ' Cancel button was pressed.
        ElseIf (result = DialogResult.Cancel) Then
            return 
        End If
    End Sub

    ' Close the current file.
    Private Sub closeMenuItem_Click(sender As object, e As System.EventArgs) _
        Handles closeMenuItem.Click
        richTextBox1.Text = "" 
        fileOpened = False 

        closeMenuItem.Enabled = False 
    End Sub

    ' Bring up a dialog to chose a folder path in which to open or save a file.
    Private Sub folderMenuItem_Click(sender As object, e As System.EventArgs) _
        Handles folderMenuItem.Click
        ' Show the FolderBrowserDialog.
        Dim result As DialogResult = folderBrowserDialog1.ShowDialog() 

        If ( result = DialogResult.OK ) Then
            folderName = folderBrowserDialog1.SelectedPath 
            If (not fileOpened) Then
                ' No file is opened, bring up openFileDialog in selected path.
                openFileDialog1.InitialDirectory = folderName 
                openFileDialog1.FileName = nothing
                openMenuItem.PerformClick() 
            End If
        End If
    End Sub

End Class

Комментарии

Конструктор без параметров инициализирует свойства значениями по умолчанию.

При создании RootFolder нового FolderBrowserDialog свойства присваивается значение Environment.SpecialFolder.Desktop, свойству Description присваивается пустая строка (""), свойству SelectedPath присваивается пустая строка, а свойству ShowNewFolderButton присваивается значение true.

Как правило, после создания нового FolderBrowserDialogзадается RootFolder в качестве расположения, из которого следует начать просмотр. При необходимости можно задать для SelectedPath путь к вложенной папке , которая будет выбрана RootFolder изначально. При необходимости можно задать Description свойство , чтобы предоставить дополнительные инструкции пользователю. Наконец, вызовите ShowDialog метод , чтобы отобразить диалоговое окно для пользователя. Если диалоговое окно закрыто и результатом ShowDialog диалога является DialogResult.OK, SelectedPath будет строкой, содержащей путь к выбранной папке.

FolderBrowserDialog — модальное диалоговое окно; Поэтому при отображении он блокирует остальную часть приложения, пока пользователь не выберет папку. Если диалоговое окно отображается модально, ввод (нажатие клавиатуры или мыши) не может происходить, кроме объектов в диалоговом окне. Программа должна скрыть или закрыть диалоговое окно (обычно в ответ на какое-либо действие пользователя), прежде чем можно будет ввести данные в вызывающую программу.

Применяется к