多文件上传功能

在以前的Web应用中，上传文件是个很麻烦的事，现在有了.NET，文件上传变得轻而易举。下面的这个例子实现了多文件上传功能。可以动态添加输入表单，上传的文件数量没有限制。代码如下：

MultiUpload.aspx

<%@ Page Language="vb" AutoEventWireup="false" Codebehind="MultiUpload.aspx.vb"
 Inherits="aspxWeb.MultiUpload" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<HTML>
  <HEAD>
    <title>多文件上传</title>
    <script language="JavaScript">
    function addFile()
    {
     var str = '<INPUT type="file" size="50" NAME="File">'
     document.getElementById('MyFile').insertAdjacentHTML("beforeEnd",str)
    }
    </script>
  </HEAD>
  <body>
    <form id="form1" method="post" runat="server" enctype="multipart/form-data">
      <center>
        <asp:Label Runat="server" ID="MyTitle"></asp:Label>
        <P id="MyFile"><INPUT type="file" size="50" NAME="File"></P>
        <P>
          <input type="button" value="增加(Add)" onclick="addFile()">
          <asp:Button Runat="server" Text="上传" ID="Upload"></asp:Button>
          <input onclick="this.form.reset()" type="button" value="重置(ReSet)">
        </P>
      </center>
      <P align="center">
        <asp:Label id="strStatus" runat="server" Font-Names="宋体" Font-Bold="True"
         Font-Size="9pt" Width="500px" BorderStyle="None" BorderColor="White"></asp:Label>
      </P>
    </form>
  </body>
</HTML>
后代码：MultiUpload.aspx.vb

Public Class MultiUpload
    Inherits System.Web.UI.Page
  Protected WithEvents Upload As System.Web.UI.WebControls.Button
  Protected WithEvents MyTitle As System.Web.UI.WebControls.Label
  Protected WithEvents strStatus As System.Web.UI.WebControls.Label

#Region " Web Form Designer Generated Code "

  'This call is required by the Web Form Designer.
  <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()

  End Sub

  Private Sub Page_Init(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Init
    'CODEGEN: This method call is required by the Web Form Designer
    'Do not modify it using the code editor.
    InitializeComponent()
  End Sub

#End Region

  Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
    MyTitle.Text = "<h3>多文件上传</h3>"
    Upload.Text = "开始上传"
    If (Me.IsPostBack) Then Me.SaveImages()
  End Sub

  Private Function SaveImages() As System.Boolean
    '遍历File表单元素
    Dim files As System.Web.HttpFileCollection = System.Web.HttpContext.Current.Request.Files

    '状态信息
    Dim strMsg As New System.Text.StringBuilder("上传的文件分别是：<hr color=red>")
    Dim iFile As System.Int32
    Try
      For iFile = 0 To files.Count - 1
        '检查文件扩展名字
        Dim postedFile As System.Web.HttpPostedFile = files(iFile)
        Dim fileName, fileExtension As System.String
        fileName = System.IO.Path.GetFileName(postedFile.FileName)
        If Not (fileName = String.Empty) Then
          fileExtension = System.IO.Path.GetExtension(fileName)
          strMsg.Append("上传的文件类型：" + postedFile.ContentType.ToString() + "<br>")
          strMsg.Append("客户端文件地址：" + postedFile.FileName + "<br>")
          strMsg.Append("上传文件的文件名：" + fileName + "<br>")
          strMsg.Append("上传文件的扩展名：" + fileExtension + "<br><hr>")
          '可根据扩展名字的不同保存到不同的文件夹
          postedFile.SaveAs(System.Web.HttpContext.Current.Request.MapPath("images/") + fileName)
        End If
      Next
      strStatus.Text = strMsg.ToString()
      Return True
    Catch Ex As System.Exception
      strStatus.Text = Ex.Message
      Return False
    End Try
  End Function
End Class
C# 版本

UpLoad.aspx

<%@ Page language="c#" Codebehind="UpLoad.aspx.cs" AutoEventWireup="false" Inherits="WebPortal.Upload" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<HTML>
  <HEAD>
    <title>多文件上传</title>
    <script language="JavaScript">
    function addFile()
    {
     var str = '<INPUT type="file" size="50" NAME="File">'
     document.getElementById('MyFile').insertAdjacentHTML("beforeEnd",str)
    }
    </script>
  </HEAD>
  <body>
    <form id="form1" method="post" runat="server" enctype="multipart/form-data">
      <div align="center">
        <h3>多文件上传</h3>
        <P id="MyFile"><INPUT type="file" size="50" NAME="File"></P>
        <P>
          <input type="button" value="增加(Add)" onclick="addFile()">
          <input onclick="this.form.reset()" type="button" value="重置(ReSet)">
          <asp:Button Runat="server" Text="开始上传" ID="UploadButton"></asp:Button>
        </P>
        <P>
        <asp:Label id="strStatus" runat="server" Font-Names="宋体" Font-Bold="True" Font-Size="9pt"
          Width="500px" BorderStyle="None" BorderColor="White"></asp:Label>
        </P>
      </div>
    </form>
  </body>
</HTML>
UpLoad.aspx.cs

using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;

namespace WebPortal
{
  /// <summary>
  /// UpLoad 的摘要说明。
  /// 实现多文件上传
  /// </summary>
  public class Upload : System.Web.UI.Page
  {
    protected System.Web.UI.WebControls.Button UploadButton;
    protected System.Web.UI.WebControls.Label strStatus;

    private void Page_Load(object sender, System.EventArgs e)
    {
      /// 在此处放置用户代码以初始化页面
      if (this.IsPostBack) this.SaveImages();
    }

    private Boolean SaveImages()
    {
      ///'遍历File表单元素
      HttpFileCollection files  = HttpContext.Current.Request.Files;

      /// '状态信息
      System.Text.StringBuilder strMsg = new System.Text.StringBuilder();
      strMsg.Append("上传的文件分别是：<hr color=red>");
      try
      {
        for(int iFile = 0; iFile < files.Count; iFile++)
        {
          ///'检查文件扩展名字
          HttpPostedFile postedFile = files[iFile];
          string fileName, fileExtension;
          fileName = System.IO.Path.GetFileName(postedFile.FileName);
          if (fileName != "")
          {
            fileExtension = System.IO.Path.GetExtension(fileName);
            strMsg.Append("上传的文件类型：" + postedFile.ContentType.ToString() + "<br>");
            strMsg.Append("客户端文件地址：" + postedFile.FileName + "<br>");
            strMsg.Append("上传文件的文件名：" + fileName + "<br>");
            strMsg.Append("上传文件的扩展名：" + fileExtension + "<br><hr>");
            ///'可根据扩展名字的不同保存到不同的文件夹
            ///注意：可能要修改你的文件夹的匿名写入权限。
            postedFile.SaveAs(System.Web.HttpContext.Current.Request.MapPath("images/") + fileName);
          }
        }
        strStatus.Text = strMsg.ToString();
        return true;
      }
      catch(System.Exception Ex)
      {
        strStatus.Text = Ex.Message;
        return false;
      }
    }
  #region Web 窗体设计器生成的代码
  override protected void OnInit(EventArgs e)
  {
  //
  // CODEGEN: 该调用是 ASP.NET Web 窗体设计器所必需的。
  //
  InitializeComponent();
  base.OnInit(e);
  }

  /// <summary>
  /// 设计器支持所需的方法 - 不要使用代码编辑器修改
  /// 此方法的内容。
  /// </summary>
  private void InitializeComponent()
  {   
    this.ID = "Upload";
    this.Load += new System.EventHandler(this.Page_Load);

  }
  #endregion
  }
}