OpenFileDialog.Multiselect Proprietà

Definizione

Spazio dei nomi:

System.Windows.Forms

Assembly:

System.Windows.Forms.dll

Origine:

OpenFileDialog.cs

Ottiene o imposta un valore che indica se la finestra di dialogo consente di selezionare più file.

public:
 property bool Multiselect { bool get(); void set(bool value); };

public bool Multiselect { get; set; }

member this.Multiselect : bool with get, set

Public Property Multiselect As Boolean

Valore della proprietà

Boolean

true se la finestra di dialogo consente di selezionare più file insieme o simultaneamente; in caso contrario, false. Il valore predefinito è false.

Esempio

L'esempio di codice seguente consente all'utente di selezionare una serie di immagini e visualizzarle nei PictureBox controlli di un modulo. Illustra l'inizializzazione di un oggetto OpenFileDialog, l'impostazione delle Title proprietà e Filter e la possibilità all'utente di selezionare più file impostando la Multiselect proprietà su true. In questo esempio di codice si presuppone che nel modulo sia già presente un OpenFileDialog controllo denominato openFileDialog1, un Button oggetto denominato SelectFileButtone un FlowLayoutPanel denominato flowLayoutPanel1.

private void Form1_Load(object sender, EventArgs e)
{
    InitializeOpenFileDialog();
}

private void InitializeOpenFileDialog()
{
    // Set the file dialog to filter for graphics files.
    this.openFileDialog1.Filter =
        "Images (*.BMP;*.JPG;*.GIF)|*.BMP;*.JPG;*.GIF|" +
        "All files (*.*)|*.*";

    // Allow the user to select multiple images.
    this.openFileDialog1.Multiselect = true;
    this.openFileDialog1.Title = "My Image Browser";
}

private void selectFilesButton_Click(object sender, EventArgs e)
{
    DialogResult dr = this.openFileDialog1.ShowDialog();
    if (dr == System.Windows.Forms.DialogResult.OK)
    {
        // Read the files
        foreach (String file in openFileDialog1.FileNames) 
        {
            // Create a PictureBox.
            try
            {
                PictureBox pb = new PictureBox();
                Image loadedImage = Image.FromFile(file);
                pb.Height = loadedImage.Height;
                pb.Width = loadedImage.Width;
                pb.Image = loadedImage;
                flowLayoutPanel1.Controls.Add(pb);
            }
            catch (SecurityException ex)
            {
                // The user lacks appropriate permissions to read files, discover paths, etc.
                MessageBox.Show("Security error. Please contact your administrator for details.\n\n" +
                    "Error message: " + ex.Message + "\n\n" +
                    "Details (send to Support):\n\n" + ex.StackTrace
                );
            }
            catch (Exception ex)
            {
                // Could not load the image - probably related to Windows file system permissions.
                MessageBox.Show("Cannot display the image: " + file.Substring(file.LastIndexOf('\\'))
                    + ". You may not have permission to read the file, or " +
                    "it may be corrupt.\n\nReported error: " + ex.Message);
            }
        }
    }

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
    InitializeOpenFileDialog()
End Sub

Private Sub SelectFileButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles SelectFileButton.Click
    Dim dr As DialogResult = OpenFileDialog1.ShowDialog()
    If (dr = System.Windows.Forms.DialogResult.OK) Then
        ' Read the files
        Dim file As String
        For Each file In OpenFileDialog1.FileNames
            ' Create a PictureBox for each file, and add that file to the FlowLayoutPanel.
            Try
                Dim pb As New PictureBox()
                Dim loadedImage As Image = Image.FromFile(file)
                pb.Height = loadedImage.Height
                pb.Width = loadedImage.Width
                pb.Image = loadedImage
                FlowLayoutPanel1.Controls.Add(pb)
            Catch SecEx As SecurityException
                ' The user lacks appropriate permissions to read files, discover paths, etc.
                MessageBox.Show("Security error. Please contact your administrator for details.\n\n" &
                    "Error message: " & SecEx.Message & "\n\n" &
                    "Details (send to Support):\n\n" & SecEx.StackTrace)
            Catch ex As Exception
                ' Could not load the image - probably permissions-related.
                MessageBox.Show(("Cannot display the image: " & file.Substring(file.LastIndexOf("\"c)) &
                ". You may not have permission to read the file, or " + "it may be corrupt." _
                & ControlChars.Lf & ControlChars.Lf & "Reported error: " & ex.Message))
            End Try
        Next file
    End If
End Sub

Public Sub InitializeOpenFileDialog()
    ' Set the file dialog to filter for graphics files.
    OpenFileDialog1.Filter =
            "Images (*.BMP;*.JPG;*.GIF)|*.BMP;*.JPG;*.GIF|" +
            "All files (*.*)|*.*"

    ' Allow the user to select multiple images.
    OpenFileDialog1.Multiselect = True
    OpenFileDialog1.Title = "My Image Browser"
End Sub

Commenti

Utilizzare la FileNames proprietà per accedere all'elenco completo dei nomi di file selezionati.

Vedi anche

• FileNames
• Filter