En este artículo Bill Evjen nos muestra cómo utilizar el nuevo FileUpload ASP.NET Server Control de ASP.NET 2.0. Para ASP.NET 1.x no hay mas que usar el File Field HTML Server Control.
<%@ Page Language="VB" %> <script runat="server"> Protected Sub Button1_Click(ByVal sender As Object, _ ByVal e As System.EventArgs) If FileUpload1.HasFile Then Try FileUpload1.SaveAs("C:\Uploads\" & _ FileUpload1.FileName) Label1.Text = "File name: " & _ FileUpload1.PostedFile.FileName & "<br>" & _ "File Size: " & _ FileUpload1.PostedFile.ContentLength & " kb<br>" & _ "Content type: " & _ FileUpload1.PostedFile.ContentType Catch ex As Exception Label1.Text = "ERROR: " & ex.Message.ToString() End Try Else Label1.Text = "You have not specified a file." End If End Sub </script> <html xmlns="http://www.w3.org/1999/xhtml" > <head runat="server"> <title>Upload Files</title> </head> <body> <form id="form1" runat="server"> <div> <asp:FileUpload ID="FileUpload1" runat="server" /><br /> <br /> <asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Upload File" /> <br /> <br /> <asp:Label ID="Label1" runat="server"></asp:Label></div> </form> </body> </html>
Para mayor información leer: Uploading Files in ASP.NET 2.0.