FileDialog.DefaultExt Propriété

Définition

Espace de noms:

System.Windows.Forms

Assembly:

System.Windows.Forms.dll

Obtient ou définit l’extension de nom de fichier par défaut.

public:
 property System::String ^ DefaultExt { System::String ^ get(); void set(System::String ^ value); };

public string DefaultExt { get; set; }

member this.DefaultExt : string with get, set

Public Property DefaultExt As String

Valeur de propriété

String

Extension de nom de fichier par défaut. La chaîne retournée ne comporte pas de point. La valeur par défaut est une chaîne vide ("").

Exemples

L’exemple de code suivant illustre l’utilisation des RichTextBox.SaveFile méthodes et RichTextBox.LoadFile avec des flux. Il illustre également l’utilisation des FileNamemembres , DefaultExt, SaveFileDialog.CreatePromptet SaveFileDialog.OverwritePrompt .

Il s’agit d’un exemple complet qui est prêt à être exécuté lorsque vous le copiez dans votre projet.

using namespace System;
using namespace System::Drawing;
using namespace System::IO;
using namespace System::Windows::Forms;

public ref class Form1: public Form
{
public private:
   RichTextBox^ RichTextBox1;
   Button^ Button1;
   RichTextBox^ RichTextBox2;
   Button^ Button2;
   SaveFileDialog^ SaveFileDialog1;

public:
   Form1()
      : Form()
   {
      userInput = gcnew MemoryStream;
      this->RichTextBox1 = gcnew RichTextBox;
      this->Button1 = gcnew Button;
      this->RichTextBox2 = gcnew RichTextBox;
      this->Button2 = gcnew Button;
      this->SaveFileDialog1 = gcnew SaveFileDialog;
      this->SuspendLayout();
      this->RichTextBox1->Location = Point( 24, 64 );
      this->RichTextBox1->Name = "RichTextBox1";
      this->RichTextBox1->TabIndex = 0;
      this->RichTextBox1->Text = "Type something here.";
      this->Button1->Location = Point( 96, 16 );
      this->Button1->Name = "Button1";
      this->Button1->Size = Size( 96, 24 );
      this->Button1->TabIndex = 1;
      this->Button1->Text = "Save To Stream";
      this->Button1->Click += 
          gcnew EventHandler( this, &Form1::Button1_Click );
      this->RichTextBox2->Location = Point( 152, 64 );
      this->RichTextBox2->Name = "RichTextBox2";
      this->RichTextBox2->TabIndex = 3;
      this->RichTextBox2->Text = "It will be added to the stream "
      "and appear here.";
      this->Button2->Location = Point( 104, 200 );
      this->Button2->Name = "Button2";
      this->Button2->Size = Size( 88, 32 );
      this->Button2->TabIndex = 4;
      this->Button2->Text = "Save Stream To File";
      this->Button2->Click += 
          gcnew EventHandler( this, &Form1::Button2_Click );
      this->ClientSize = Size( 292, 266 );
      this->Controls->Add( this->Button2 );
      this->Controls->Add( this->RichTextBox2 );
      this->Controls->Add( this->Button1 );
      this->Controls->Add( this->RichTextBox1 );
      this->Name = "Form1";
      this->Text = "Form1";
      this->ResumeLayout( false );
   }

   // Declare a new memory stream.
   MemoryStream^ userInput;

private:

   // Save the content of RichTextBox1 to the memory stream, 
   // appending a LineFeed character.  
   void Button1_Click( Object^ /*sender*/, EventArgs^ /*e*/ )
   {
      RichTextBox1->SaveFile( userInput, RichTextBoxStreamType::PlainText );
      userInput->WriteByte( 13 );
      
      // Display the entire contents of the stream,
      // by setting its position to 0, to RichTextBox2.
      userInput->Position = 0;
      RichTextBox2->LoadFile( userInput, RichTextBoxStreamType::PlainText );
   }


   // Shows the use of a SaveFileDialog to save a MemoryStream to a file.
   void Button2_Click( Object^ /*sender*/, EventArgs^ /*e*/ )
   {
      
      // Set the properties on SaveFileDialog1 so the user is 
      // prompted to create the file if it doesn't exist 
      // or overwrite the file if it does exist.
      SaveFileDialog1->CreatePrompt = true;
      SaveFileDialog1->OverwritePrompt = true;
      
      // Set the file name to myText.txt, set the type filter
      // to text files, and set the initial directory to the
      // MyDocuments folder.
      SaveFileDialog1->FileName = "myText";
      // DefaultExt is only used when "All files" is selected from 
      // the filter box and no extension is specified by the user.
      SaveFileDialog1->DefaultExt = "txt";
      SaveFileDialog1->Filter = "Text files (*.txt)|*.txt|All files (*.*)|*.*";
      SaveFileDialog1->InitialDirectory = 
          Environment->GetFolderPath(Environment::SpecialFolder::MyDocuments);
      
      // Call ShowDialog and check for a return value of DialogResult.OK,
      // which indicates that the file was saved. 
      DialogResult result = SaveFileDialog1->ShowDialog();
      Stream^ fileStream;
      if ( result == DialogResult::OK )
      {
         fileStream = SaveFileDialog1->OpenFile();
         userInput->Position = 0;
         userInput->WriteTo( fileStream );
         fileStream->Close();
      }
   }
};

int main()
{
   Application::Run( gcnew Form1 );
}

using System;
using System.Drawing;
using System.IO;
using System.Windows.Forms;

public partial class Form1: Form
{
    internal RichTextBox RichTextBox1;
    internal Button Button1;
    internal RichTextBox RichTextBox2;
    internal Button Button2;
    internal SaveFileDialog SaveFileDialog1;

    public Form1() : base()
    {   
        this.RichTextBox1 = new RichTextBox();
        this.Button1 = new Button();
        this.RichTextBox2 = new RichTextBox();
        this.Button2 = new Button();
        this.SaveFileDialog1 = new SaveFileDialog();
        this.SuspendLayout();
        this.RichTextBox1.Location = new Point(24, 64);
        this.RichTextBox1.Name = "RichTextBox1";
        this.RichTextBox1.TabIndex = 0;
        this.RichTextBox1.Text = "Type something here.";
        this.Button1.Location = new Point(96, 16);
        this.Button1.Name = "Button1";
        this.Button1.Size = new Size(96, 24);
        this.Button1.TabIndex = 1;
        this.Button1.Text = "Save To Stream";
        this.Button1.Click += new EventHandler(Button1_Click);
        this.RichTextBox2.Location = new Point(152, 64);
        this.RichTextBox2.Name = "RichTextBox2";
        this.RichTextBox2.TabIndex = 3;
        this.RichTextBox2.Text = 
            "It will be added to the stream and appear here.";
        this.Button2.Location = new Point(104, 200);
        this.Button2.Name = "Button2";
        this.Button2.Size = new Size(88, 32);
        this.Button2.TabIndex = 4;
        this.Button2.Text = "Save Stream To File";
        this.Button2.Click += new EventHandler(Button2_Click);
        this.ClientSize = new Size(292, 266);
        this.Controls.Add(this.Button2);
        this.Controls.Add(this.RichTextBox2);
        this.Controls.Add(this.Button1);
        this.Controls.Add(this.RichTextBox1);
        this.Name = "Form1";
        this.Text = "Form1";
        this.ResumeLayout(false);
    }

    public static void Main()
    {
        Application.Run(new Form1());
    }

    // Declare a new memory stream.
    MemoryStream userInput = new MemoryStream();

    // Save the content of RichTextBox1 to the memory stream, 
    // appending a LineFeed character.  
    private void Button1_Click(Object sender, EventArgs e)
    {
        RichTextBox1.SaveFile(userInput, RichTextBoxStreamType.PlainText);
        userInput.WriteByte(13);

        // Display the entire contents of the stream,
        // by setting its position to 0, to RichTextBox2.
        userInput.Position = 0;
        RichTextBox2.LoadFile(userInput, RichTextBoxStreamType.PlainText);
    }

    // Shows the use of a SaveFileDialog to save a MemoryStream to a file.
    private void Button2_Click(Object sender, EventArgs e)
    {
        // Set the properties on SaveFileDialog1 so the user is 
        // prompted to create the file if it doesn't exist 
        // or overwrite the file if it does exist.
        SaveFileDialog1.CreatePrompt = true;
        SaveFileDialog1.OverwritePrompt = true;

        // Set the file name to myText.txt, set the type filter
        // to text files, and set the initial directory to the 
        // MyDocuments folder.
        SaveFileDialog1.FileName = "myText";
        // DefaultExt is only used when "All files" is selected from 
        // the filter box and no extension is specified by the user.
        SaveFileDialog1.DefaultExt = "txt";
        SaveFileDialog1.Filter = 
            "Text files (*.txt)|*.txt|All files (*.*)|*.*";
        SaveFileDialog1.InitialDirectory = 
            Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);

        // Call ShowDialog and check for a return value of DialogResult.OK,
        // which indicates that the file was saved. 
        DialogResult result = SaveFileDialog1.ShowDialog();
        Stream fileStream;

        if (result == DialogResult.OK)
        {
            // Open the file, copy the contents of memoryStream to fileStream,
            // and close fileStream. Set the memoryStream.Position value to 0 
            // to copy the entire stream. 
            fileStream = SaveFileDialog1.OpenFile();
            userInput.Position = 0;
            userInput.WriteTo(fileStream);
            fileStream.Close();
        }
    }
}

Imports System.Drawing
Imports System.IO
Imports System.Windows.Forms

Partial Public Class Form1
    Inherits Form

    Friend WithEvents RichTextBox1 As RichTextBox
    Friend WithEvents Button1 As Button
    Friend WithEvents RichTextBox2 As RichTextBox
    Friend WithEvents Button2 As Button
    Friend WithEvents SaveFileDialog1 As SaveFileDialog

    Public Sub New()
        MyBase.New()
        Me.RichTextBox1 = New RichTextBox
        Me.Button1 = New Button
        Me.RichTextBox2 = New RichTextBox
        Me.Button2 = New Button
        Me.SaveFileDialog1 = New SaveFileDialog
        Me.SuspendLayout()
        Me.RichTextBox1.Location = New Point(24, 64)
        Me.RichTextBox1.Name = "RichTextBox1"
        Me.RichTextBox1.TabIndex = 0
        Me.RichTextBox1.Text = "Type something here."
        Me.Button1.Location = New Point(96, 16)
        Me.Button1.Name = "Button1"
        Me.Button1.Size = New Size(96, 24)
        Me.Button1.TabIndex = 1
        Me.Button1.Text = "Save To Stream"
        Me.RichTextBox2.Location = New Point(152, 64)
        Me.RichTextBox2.Name = "RichTextBox2"
        Me.RichTextBox2.TabIndex = 3
        Me.RichTextBox2.Text = "It will be added to the stream and appear here."
        Me.Button2.Location = New Point(104, 200)
        Me.Button2.Name = "Button2"
        Me.Button2.Size = New Size(88, 32)
        Me.Button2.TabIndex = 4
        Me.Button2.Text = "Save Stream To File"
        Me.ClientSize = New Size(292, 266)
        Me.Controls.Add(Me.Button2)
        Me.Controls.Add(Me.RichTextBox2)
        Me.Controls.Add(Me.Button1)
        Me.Controls.Add(Me.RichTextBox1)
        Me.Name = "Form1"
        Me.Text = "Form1"
        Me.ResumeLayout(False)

    End Sub

    Public Shared Sub Main()
        Application.Run(New Form1)
    End Sub

    ' Declare a new memory stream.
    Dim userInput As New MemoryStream

    ' Save the content of RichTextBox1 to the memory stream, appending
    'a LineFeed character.  
    Private Sub Button1_Click(ByVal sender As Object, _
        ByVal e As EventArgs) Handles Button1.Click
        RichTextBox1.SaveFile(userInput, RichTextBoxStreamType.PlainText)
        userInput.WriteByte(13)

        ' Display the entire contents of the stream,
        ' by setting its position to 0, to RichTextBox2.
        userInput.Position = 0
        RichTextBox2.LoadFile(userInput, RichTextBoxStreamType.PlainText)
    End Sub

    ' Shows the use of a SaveFileDialog to save a MemoryStream to a file.
    Private Sub Button2_Click(ByVal sender As Object, _
        ByVal e As EventArgs) Handles Button2.Click

        ' Set the properties on SaveFileDialog1 so the user is 
        ' prompted to create the file if it doesn't exist 
        ' or overwrite the file if it does exist.
        SaveFileDialog1.CreatePrompt = True
        SaveFileDialog1.OverwritePrompt = True

        ' Set the file name to myText.txt, set the type filter
        ' to text files, and set the initial directory to the 
        ' MyDocuments folder.
        SaveFileDialog1.FileName = "myText"
        ' DefaultExt is only used when "All files" is selected from 
        ' the filter box and no extension is specified by the user.
        SaveFileDialog1.DefaultExt = "txt"
        SaveFileDialog1.Filter = "Text files (*.txt)|*.txt|All files (*.*)|*.*"
        SaveFileDialog1.InitialDirectory = _
            Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments)

        ' Call ShowDialog and check for a return value of DialogResult.OK,
        ' which indicates that the file was saved. 
        Dim result As DialogResult = SaveFileDialog1.ShowDialog()
        Dim fileStream As Stream

        If (result = DialogResult.OK) Then
            ' Open the file, copy the contents of memoryStream to fileStream,
            ' and close fileStream. Set the memoryStream.Position value to 0 to 
            ' copy the entire stream. 
            fileStream = SaveFileDialog1.OpenFile()
            userInput.Position = 0
            userInput.WriteTo(fileStream)
            fileStream.Close()
        End If
    End Sub

End Class

Remarques

Lorsque l’utilisateur de votre application spécifie un nom de fichier sans extension, le FileDialog ajoute une extension au nom de fichier. L’extension utilisée est déterminée par les Filter propriétés et DefaultExt . Si un filtre est sélectionné dans et FileDialog que le filtre spécifie une extension, cette extension est utilisée. Si le filtre sélectionné utilise un caractère générique à la place de l’extension, l’extension spécifiée dans la DefaultExt propriété est utilisée.