ASP.NET(C#)实现一次性上传多张图片（多个文件）_c#一次选中多张图片上传-优快云博客

本文介绍如何使用ASP.NET和C#实现一次性上传多张图片的功能。通过客户端JavaScript动态添加文件输入框，限制上传图片数量，并在服务器端进行格式及大小验证。

ASP.NET(C#)实现一次性上传多张图片（多个文件）
HTML文件：

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="FileUp.aspx.cs" Inherits="FileUp" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<title>ASP.NET(C#)实现一次性上传多张图片（多个文件）</title>

var i=1;

function addFile()

{

if (i<8)

{

var str = '<BR> <input type="file" name="File" runat="server" style="width: 200px"/>描述：<input name="text" type="text" style="width: 150px" maxlength="20" />';

document.getElementById('MyFile').insertAdjacentHTML("beforeEnd",str);

}

else

{

alert("您一次最多只能上传8张图片！");

}

i++;

}

</script>

</head>

<body>

<div>

<tr>

</tr>

<tr>

</tr>

<tr>

<asp:Panel ID="Panel5" runat="server">

<tr>

<td align="left" style="width: 500px">说明：点增加图片按钮可一次上传多张图片，可为每张图片写上一句不超过20个字的描述。单张图片大小不大于1024k</td>

</tr>

<tr>

<td align="right" style="width: 100px">请选择图片：<br /></td>

</tr>

<tr>

</tr>

<tr>

</tr>

</table>

</asp:Panel>

</td>

</tr>

<tr>

</tr>

</table>

</div>

</form>

</body>

</html>

cs文件：

using System;

using System.Data;

using System.Configuration;

using System.Collections;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Web.UI.HtmlControls;

using System.IO;

public partial class FileUp : System.Web.UI.Page

{

protected void Page_Load(object sender, EventArgs e)

{

}

protected void btnUpload_Click(object sender, EventArgs e)

{

lblMessage.Text = "";

lblMessage.Visible = false;

System.Web.HttpFileCollection files = System.Web.HttpContext.Current.Request.Files;

System.Text.StringBuilder strmsg = new System.Text.StringBuilder("");

string[] rd = Request.Form[1].Split(',');//获得图片描述的文本框字符串数组，为对应的图片的描述

//string albumid=ddlAlbum.SelectedValue.Trim();

int ifile;

for (ifile = 0; ifile < files.Count; ifile++)

{

if (files[ifile].FileName.Length > 0)

{

System.Web.HttpPostedFile postedfile = files[ifile];

if (postedfile.ContentLength / 1024 > 1024)//单个文件不能大于1024k

{

strmsg.Append(Path.GetFileName(postedfile.FileName) + "---不能大于1024k<br>");

break;

}

string fex = Path.GetExtension(postedfile.FileName);

if (fex != ".jpg" && fex != ".JPG" && fex != ".gif" && fex != ".GIF")

{

strmsg.Append(Path.GetFileName(postedfile.FileName) + "---图片格式不对，只能是jpg或gif<br>");

break;

}

if (strmsg.Length <= 0) //说明图片大小和格式都没问题

{

//以下为创建图库目录

string dirpath = Server.MapPath("51aspx");

if (Directory.Exists(dirpath) == false)

{

Directory.CreateDirectory(dirpath);

}

Random ro = new Random();

int name = 1;

for (int i = 0; i < files.Count; i++)

{

System.Web.HttpPostedFile myFile = files[i];

string FileName = "";

string FileExtention = "";

FileName = System.IO.Path.GetFileName(myFile.FileName);

string stro = ro.Next(100, 100000000).ToString() + name.ToString();//产生一个随机数用于新命名的图片

string NewName = DateTime.Now.Minute.ToString() + DateTime.Now.Second.ToString() + DateTime.Now.Millisecond.ToString() + stro;

if (FileName.Length > 0)//有文件才执行上传操作再保存到数据库

{

FileExtention = System.IO.Path.GetExtension(myFile.FileName);

string ppath = dirpath + @"" + NewName + FileExtention;

myFile.SaveAs(ppath);

}

name = name + 1;//用来重命名规则的变量

}

Response.Write("<script>alert('恭喜，图片上传成功！')</script>");

}

else

{

lblMessage.Text = strmsg.ToString();

lblMessage.Visible = true;

}