OpenFileDialog.Multiselect 属性

定义

命名空间:

System.Windows.Forms

程序集:

System.Windows.Forms.dll

获取或设置一个值，该值指示对话框是否允许选择多个文件。

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

属性值

Boolean

如果对话框允许同时选定多个文件，则为 true；反之，则为 false。 默认值是 false。

示例

下面的代码示例允许用户选择多个图像，并在窗体上的控件中 PictureBox 显示它们。 它演示了初始化 OpenFileDialog、设置 Title 和 Filter 属性，以及允许用户通过将 属性设置为 Multiselect true 来选择多个文件。 此代码示例假定窗体已有一OpenFileDialog个名为 、SelectFileButtonButton名为 openFileDialog1的控件和一FlowLayoutPanel个名为 的flowLayoutPanel1控件。

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 = Me.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.
    Me.OpenFileDialog1.Filter = _
            "Images (*.BMP;*.JPG;*.GIF)|*.BMP;*.JPG;*.GIF|" + _
            "All files (*.*)|*.*"

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

注解

FileNames使用 属性访问所选文件名的完整列表。

另请参阅

• FileNames
• Filter