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FolderBrowserDialog Konstruktor

Definition

Initialisiert eine neue Instanz der FolderBrowserDialog-Klasse.

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

Beispiele

Im folgenden Codebeispiel wird eine Anwendung erstellt, mit der der Benutzer Rich-Text-Dateien (RTF) innerhalb des RichTextBox Steuerelements öffnen kann.

// 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 MainMenu mainMenu1;
    private MenuItem fileMenuItem, openMenuItem;
    private MenuItem 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 System.Windows.Forms.MainMenu();
        this.fileMenuItem = new System.Windows.Forms.MenuItem();
        this.openMenuItem = new System.Windows.Forms.MenuItem();
        this.folderMenuItem = new System.Windows.Forms.MenuItem();
        this.closeMenuItem = new System.Windows.Forms.MenuItem();

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

        this.mainMenu1.MenuItems.Add(this.fileMenuItem);
        this.fileMenuItem.MenuItems.AddRange(
                            new System.Windows.Forms.MenuItem[] {this.openMenuItem,
                                                                 this.closeMenuItem,
                                                                 this.folderMenuItem});
        this.fileMenuItem.Text = "File";

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

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

        this.closeMenuItem.Text = "Close";
        this.closeMenuItem.Click += new System.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, 8);
        this.richTextBox1.Size = new System.Drawing.Size(280, 344);
        this.richTextBox1.Anchor = AnchorStyles.Top | AnchorStyles.Left | 
                                   AnchorStyles.Bottom | AnchorStyles.Right;

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

    // Bring up a dialog to open a file.
    private 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 = 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, System.EventArgs e)
    {
        richTextBox1.Text = "";
        fileOpened = false;

        closeMenuItem.Enabled = false;
    }

    // Bring up a dialog to chose a folder path in which to open or save a file.
    private void folderMenuItem_Click(object sender, System.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

Hinweise

Der parameterlose Konstruktor initialisiert Eigenschaften auf ihre Standardwerte.

Wenn eine neue FolderBrowserDialog Erstellt wird, wird die RootFolder Eigenschaft auf eine leere Zeichenfolge ("") SelectedPath festgelegtEnvironment.SpecialFolder.DesktopDescription, die Eigenschaft wird auf eine leere Zeichenfolge festgelegt, und die Eigenschaft wird auf eine leere Zeichenfolge festgelegt, und die ShowNewFolderButton Eigenschaft wird auf truefestgelegt.

Normalerweise legen Sie nach dem Erstellen eines neuen FolderBrowserDialogElements den RootFolder Speicherort fest, von dem sie mit dem Surfen beginnen sollen. Optional können Sie den SelectedPath Pfad eines Unterordners festlegen, der RootFolder anfänglich ausgewählt wird. Sie können die Description Eigenschaft optional auch so festlegen, dass dem Benutzer zusätzliche Anweisungen bereitgestellt werden. Rufen Sie schließlich die ShowDialog Methode auf, um das Dialogfeld für den Benutzer anzuzeigen. Wenn das Dialogfeld geschlossen ist und das Dialogfeld ergebnis ist ShowDialog DialogResult.OK, ist dies eine Zeichenfolge, die SelectedPath den Pfad zum ausgewählten Ordner enthält.

FolderBrowserDialog ist ein modales Dialogfeld; Wenn dies angezeigt wird, blockiert sie den Rest der Anwendung, bis der Benutzer einen Ordner ausgewählt hat. Wenn ein Dialogfeld modal angezeigt wird, kann keine Eingabe (Tastatur oder Mausklick) auftreten, außer für Objekte im Dialogfeld. Das Programm muss das Dialogfeld ausblenden oder schließen (in der Regel als Reaktion auf einige Benutzeraktionen), bevor die Eingabe an das aufrufende Programm auftreten kann.

Gilt für