使用OpenFilleDailog打开文件。

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim fdlg As OpenFileDialog = New OpenFileDialog()
        fdlg.Title = "VB.net打开文件对话框的使用"
        fdlg.InitialDirectory = "c:\"
        fdlg.Filter = "All files (*.*)|*.*"
        fdlg.FilterIndex = 2
        fdlg.RestoreDirectory = True
        If fdlg.ShowDialog() = DialogResult.OK Then
            TextBox1.Text = fdlg.FileName
        End If
    End Sub


附上示例的所有代码：（UseOpenFileDailog.VB)
Public Class UseOpenFileDialog
    Inherits System.Windows.Forms.Form

#Region " Windows Form Designer generated code "

    Public Sub New()
        MyBase.New()

        @#This call is required by the Windows Form Designer.
        InitializeComponent()

        @#Add any initialization after the InitializeComponent() call

    End Sub

    @#Form overrides dispose to clean up the component list.
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub

    @#Required by the Windows Form Designer
    Private components As System.ComponentModel.IContainer

    @#NOTE: The following procedure is required by the Windows Form Designer
    @#It can be modified using the Windows Form Designer.  
    @#Do not modify it using the code editor.
    Friend WithEvents TextBox1 As System.Windows.Forms.TextBox
    Friend WithEvents Button1 As System.Windows.Forms.Button
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.TextBox1 = New System.Windows.Forms.TextBox()
        Me.Button1 = New System.Windows.Forms.Button()
        Me.SuspendLayout()
        @#
        @#TextBox1
        @#
        Me.TextBox1.Location = New System.Drawing.Point(72, 72)
        Me.TextBox1.Name = "TextBox1"
        Me.TextBox1.Size = New System.Drawing.Size(120, 20)
        Me.TextBox1.TabIndex = 0
        Me.TextBox1.Text = "TextBox1"
        @#
        @#Button1
        @#
        Me.Button1.Location = New System.Drawing.Point(208, 72)
        Me.Button1.Name = "Button1"
        Me.Button1.Size = New System.Drawing.Size(32, 24)
        Me.Button1.TabIndex = 1
        Me.Button1.Text = "Button1"
        @#
        @#UseOpenFileDialog
        @#
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.ClientSize = New System.Drawing.Size(292, 213)
        Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.Button1, Me.TextBox1})
        Me.Name = "UseOpenFileDialog"
        Me.Text = "UseOpenFileDialog"
        Me.ResumeLayout(False)

    End Sub

#End Region

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim fdlg As OpenFileDialog = New OpenFileDialog()
        fdlg.Title = "C# Corner Open File Dialog"
        fdlg.InitialDirectory = "c:\"
        fdlg.Filter = "All files (*.*)|*.*"
        fdlg.FilterIndex = 2
        fdlg.RestoreDirectory = True
        If fdlg.ShowDialog() = DialogResult.OK Then
            TextBox1.Text = fdlg.FileName
        End If
    End Sub
End Class

原文转自：http://www.ltesting.net