使用标准HTML来进行图片上传

本文介绍了ASP.NET中几种常见的文件上传方法,包括单文件上传、多文件上传及客户端和服务端的文件类型检查。通过示例代码展示了如何实现这些功能。

摘要生成于 C知道 ,由 DeepSeek-R1 满血版支持, 前往体验 >

<body>
   
<form id="form1" runat="server">
   
<div>
       
<table>
           
<tr>
               
<td colspan="2" style="height: 21px" >
                    使用标准HTML来进行图片上传
</td>
           
</tr>
           
<tr>
               
<td style="width: 400px">
                   
<input id="InputFile" style="width: 399px" type="file" runat="server" /></td>
               
<td style="width: 80px">
                   
<asp:Button ID="UploadButton" runat="server" Text="上传图片" OnClick="UploadButton_Click" /></td>
           
</tr>
           
<tr>
               
<td colspan="2" >
                   
<asp:Label ID="Lb_Info" runat="server" ForeColor="Red"></asp:Label></td>                
           
</tr>
       
</table>    
   
</div>
   
</form>
</body>


后台代码:

<!--

Code highlighting produced by Actipro CodeHighlighter (freeware)
http://www.CodeHighlighter.com/

-->using System;
using System.Data;
using System.Configuration;
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;

public partial class _Default : System.Web.UI.Page 
{
   
protected void Page_Load(object sender, EventArgs e)
    {

    }
   
protected void UploadButton_Click(object sender, EventArgs e)
    {
       
string uploadName = InputFile.Value;//获取待上传图片的完整路径,包括文件名
       
//string uploadName = InputFile.PostedFile.FileName;
        string pictureName = "";//上传后的图片名,以当前时间为文件名,确保文件名没有重复
        if (InputFile.Value != "")
        {
           
int idx = uploadName.LastIndexOf(".");
           
string suffix = uploadName.Substring(idx);//获得上传的图片的后缀名
            pictureName = DateTime.Now.Ticks.ToString() + suffix;
        }
       
try
        {
           
if (uploadName != "")
            {
               
string path = Server.MapPath("~/images/");
                InputFile.PostedFile.SaveAs(path
+ pictureName);
            }
        }
       
catch (Exception ex)
        {
            Response.Write(ex);
        }
    }
}


2 单文件上传

        这是最基本的文件上传,在asp.net1.x中没有这个FileUpload控件,只有html的上传控件,那时候要把html控件转化为服务器控件,很不好用。其实所有文件上传的美丽效果都是从这个FileUpload控件衍生,第一个例子虽然简单却是根本。

前台代码:

<!--

Code highlighting produced by Actipro CodeHighlighter (freeware)
http://www.CodeHighlighter.com/

--><body>
   
<form id="form1" runat="server">
   
<div>
       
<table style="width: 90%">
           
<tr>
               
<td style="width: 159px" colspan=2>
                   
<strong><span style="font-size: 10pt">最简单的单文件上传</span></strong></td>
           
</tr>
           
<tr>
               
<td style="width: 600px">
                   
<asp:FileUpload ID="FileUpload1" runat="server" Width="600px" /></td>
               
<td align=left>
                   
<asp:Button ID="FileUpload_Button" runat="server" Text="上传图片" OnClick="FileUpload_Button_Click" /></td>
           
</tr>
           
<tr>
               
<td colspan=2>
                   
<asp:Label ID="Upload_info" runat="server" ForeColor="Red" Width="767px"></asp:Label></td>
           
</tr>
       
</table>    
   
</div>
   
</form>
</body>

后台代码:

<!--

Code highlighting produced by Actipro CodeHighlighter (freeware)
http://www.CodeHighlighter.com/

-->using System;
using System.Data;
using System.Configuration;
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;

public partial class _Default : System.Web.UI.Page 
{
   
protected void Page_Load(object sender, EventArgs e)
    {

    }
   
protected void FileUpload_Button_Click(object sender, EventArgs e)
    {
       
try
        {
           
if (FileUpload1.PostedFile.FileName == "")
           
//if (FileUpload1.FileName == "")
           
//if (!FileUpload1.HasFile)     //获取一个值,该值指示 System.Web.UI.WebControls.FileUpload 控件是否包含文件。包含文件,则为 true;否则为 false。
            {
               
this.Upload_info.Text = "请选择上传文件!";
            }
           
else
            {
               
string filepath = FileUpload1.PostedFile.FileName;  //得到的是文件的完整路径,包括文件名,如:C:\Documents and Settings\Administrator\My Documents\My Pictures\20022775_m.jpg
               
//string filepath = FileUpload1.FileName;               //得到上传的文件名20022775_m.jpg
                string filename = filepath.Substring(filepath.LastIndexOf("\\") + 1);//20022775_m.jpg
                string serverpath = Server.MapPath("~/images/") + filename;//取得文件在服务器上保存的位置C:\Inetpub\wwwroot\WebSite1\images\20022775_m.jpg
                FileUpload1.PostedFile.SaveAs(serverpath);//将上传的文件另存为
                this.Upload_info.Text = "上传成功!";
            }
        }
       
catch (Exception ex)
        {
           
this.Upload_info.Text = "上传发生错误!原因是:" + ex.ToString();
        }
    }
}




3 多文件上传

前台代码:

<!--

Code highlighting produced by Actipro CodeHighlighter (freeware)
http://www.CodeHighlighter.com/

--><body>
   
<form id="form1" runat="server">
   
<div>
   
<table style="width: 343px">
           
<tr>
               
<td style="width: 100px">
                    多文件上传
</td>
               
<td style="width: 100px">
               
</td>
           
</tr>
           
<tr>
               
<td style="width: 100px">
                   
<asp:FileUpload ID="FileUpload1" runat="server" Width="475px" />
                   
</td>
               
<td style="width: 100px">
                   
</td>
           
</tr>
           
<tr>
               
<td style="width: 100px">
                   
<asp:FileUpload ID="FileUpload2" runat="server" Width="475px" /></td>
               
<td style="width: 100px">
               
</td>
           
</tr>
           
<tr>
               
<td style="width: 100px">
                   
<asp:FileUpload ID="FileUpload3" runat="server" Width="475px" /></td>
               
<td style="width: 100px">
               
</td>
           
</tr>
           
<tr>
               
<td style="width: 100px">
                   
<asp:Button ID="bt_upload" runat="server" OnClick="bt_upload_Click" Text="一起上传" />
                   
<asp:Label ID="lb_info" runat="server" ForeColor="Red" Width="448px"></asp:Label></td>
               
<td style="width: 100px">
               
</td>
           
</tr>
       
</table>
   
</div>
   
</form>
</body>

后台代码:

<!--

Code highlighting produced by Actipro CodeHighlighter (freeware)
http://www.CodeHighlighter.com/

-->using System;
using System.Data;
using System.Configuration;
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;

public partial class _Default : System.Web.UI.Page 
{
   
protected void Page_Load(object sender, EventArgs e)
    {

    }
   
protected void bt_upload_Click(object sender, EventArgs e)
    {
       
if (FileUpload1.PostedFile.FileName == "" && FileUpload2.PostedFile.FileName == "" && FileUpload3.PostedFile.FileName == "")
        {
           
this.lb_info.Text = "请选择文件!";
        }
       
else
        {
            HttpFileCollection myfiles
= Request.Files;
           
for (int i = 0; i < myfiles.Count; i++)
            {
                HttpPostedFile mypost
= myfiles[i];
               
try
                {
                   
if (mypost.ContentLength > 0)
                    {
                       
string filepath = mypost.FileName;//C:\Documents and Settings\Administrator\My Documents\My Pictures\20022775_m.jpg
                        string filename = filepath.Substring(filepath.LastIndexOf("\\") + 1);//20022775_m.jpg
                        string serverpath = Server.MapPath("~/images/") + filename;//C:\Inetpub\wwwroot\WebSite2\images\20022775_m.jpg
                        mypost.SaveAs(serverpath);
                       
this.lb_info.Text = "上传成功!";
                    }
                }
               
catch (Exception ex)
                {
                   
this.lb_info.Text = "上传发生错误!原因:" + ex.Message.ToString();
                }
            }
        }
    }
}


 

4 客户端检查上传文件类型(以上传图片为例)

<!--

Code highlighting produced by Actipro CodeHighlighter (freeware)
http://www.CodeHighlighter.com/

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

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

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
   
<title>客户端检查上传文件类型</title>
   
<script language="javascript">
   
function Check_FileType()
    {
       
var str=document.getElementById("FileUpload1").value;
       
var pos=str.lastIndexOf(".");
       
var lastname=str.substring(pos,str.length);
       
if(lastname.toLowerCase()!=".jpg"&&lastname.toLowerCase()!=".gif")
        {
            alert(
"您上传的文件类型为"+lastname+",图片必须为.jpg,.gif类型");
           
return false;
        }
       
else
        {
           
return true;
        }        
    }
   
</script>
</head>
<body>
   
<form id="form1" runat="server">
   
<div>
       
<table>
           
<tr>
               
<td colspan="2">
                    客户端检查上传文件类型
</td>                
           
</tr>
           
<tr>
               
<td style="width: 444px">
                   
<asp:FileUpload ID="FileUpload1" runat="server" Width="432px" /></td>
               
<td style="width: 80px">
                   
<asp:Button ID="bt_upload" runat="server" Text="上传图片" OnClick="bt_upload_Click" OnClientClick="return Check_FileType()" /></td>
           
</tr>
           
<tr>
               
<td colspan="2" style="height: 21px">
                   
<asp:Label ID="lb_info" runat="server" ForeColor="Red" Width="515px"></asp:Label></td>                
           
</tr>
       
</table>    
   
</div>
   
</form>
</body>
</html>


注意:点击上传时先触发客户端事件OnClientClick="return Check_FileType()"

<!--

Code highlighting produced by Actipro CodeHighlighter (freeware)
http://www.CodeHighlighter.com/

-->using System;
using System.Data;
using System.Configuration;
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;

public partial class _Default : System.Web.UI.Page 
{
   
protected void Page_Load(object sender, EventArgs e)
    {

    }

   
protected void bt_upload_Click(object sender, EventArgs e)
    {
       
try
        {
           
if (FileUpload1.PostedFile.FileName == "")
            {
               
this.lb_info.Text = "请选择文件!";
            }
           
else
            {
               
string filepath = FileUpload1.PostedFile.FileName;
               
//if (!IsAllowedExtension(FileUpload1))
               
//{
               
//    this.lb_info.Text = "上传文件格式不正确!";
               
//}
                if (IsAllowedExtension(FileUpload1) == true)
                {
                   
string filename = filepath.Substring(filepath.LastIndexOf("\\") + 1);
                   
string serverpath = Server.MapPath("~/images/") + filename;
                    FileUpload1.PostedFile.SaveAs(serverpath);
                   
this.lb_info.Text = "上传成功!";
                }
               
else
                {
                   
this.lb_info.Text = "请上传图片!";
                }
            }
        }
       
catch (Exception ex)
        {
           
this.lb_info.Text = "上传发生错误!原因:" + ex.ToString();
        }
    }
   
private static bool IsAllowedExtension(FileUpload upfile)
    {
       
string strOldFilePath = "";
       
string strExtension="";
       
string[] arrExtension ={ ".gif", ".jpg", ".bmp", ".png" };
       
if (upfile.PostedFile.FileName != string.Empty)
        {
            strOldFilePath
= upfile.PostedFile.FileName;//获得文件的完整路径名
            strExtension = strOldFilePath.Substring(strOldFilePath.LastIndexOf("."));//获得文件的扩展名,如:.jpg
            for (int i = 0; i < arrExtension.Length; i++)
            {
               
if (strExtension.Equals(arrExtension[i]))
                {
                   
return true;
                }
            }
        }
       
return false;
    }
}


注意:若去掉客户端的脚本和客户端事件OnClientClick="return Check_FileType()",在后台代码
改为:

<!--

Code highlighting produced by Actipro CodeHighlighter (freeware)
http://www.CodeHighlighter.com/

-->if (!IsAllowedExtension(FileUpload1))
                {
                   
this.lb_info.Text = "上传文件格式不正确!";
                }
else if (IsAllowedExtension(FileUpload1) == true)


即变成服务器端检查上传文件类型。

5  服务器端检查上传文件的类型(文件内部真正的格式)

<!--

Code highlighting produced by Actipro CodeHighlighter (freeware)
http://www.CodeHighlighter.com/

--><body>
   
<form id="form1" runat="server">
   
<div>
       
<table>
           
<tr>
               
<td colspan="2">
                    服务器检查上传文件类型
</td>                
           
</tr>
           
<tr>
               
<td style="width: 444px">
                   
<asp:FileUpload ID="FileUpload1" runat="server" Width="432px" /></td>
               
<td style="width: 80px">
                   
<asp:Button ID="bt_upload" runat="server" Text="上传图片" OnClick="bt_upload_Click" /></td>
           
</tr>
           
<tr>
               
<td colspan="2" style="height: 21px">
                   
<asp:Label ID="lb_info" runat="server" ForeColor="Red" Width="515px"></asp:Label></td>                
           
</tr>
       
</table>    
   
</div>
   
</form>
</body>

后台代码:

<!--

Code highlighting produced by Actipro CodeHighlighter (freeware)
http://www.CodeHighlighter.com/

-->using System;
using System.Data;
using System.Configuration;
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 _Default : System.Web.UI.Page 
{
   
protected void Page_Load(object sender, EventArgs e)
    {

    }
   
protected void bt_upload_Click(object sender, EventArgs e)
    {
       
try
        {
           
if (FileUpload1.PostedFile.FileName == "")
            {
               
this.lb_info.Text = "请选择文件!";
            }
           
else
            {
               
string filepath = FileUpload1.PostedFile.FileName;
               
if (IsAllowedExtension(FileUpload1) == true)
                {
                   
string filename = filepath.Substring(filepath.LastIndexOf("\\") + 1);
                   
string serverpath = Server.MapPath("images/") + filename;
                    FileUpload1.PostedFile.SaveAs(serverpath);
                   
this.lb_info.Text = "上传成功!";
                }
               
else
                {
                   
this.lb_info.Text = "请上传图片";
                }
            }
        }
       
catch (Exception error)
        {
           
this.lb_info.Text = "上传发生错误!原因:" + error.ToString();
        }
    }
   
private static bool IsAllowedExtension(FileUpload upfile)
    {
        FileStream fs
= new FileStream(upfile.PostedFile.FileName, FileMode.Open, FileAccess.Read);
        BinaryReader r
= new BinaryReader(fs);
       
string fileclass = "";
       
byte buffer;
       
try
        {
            buffer
= r.ReadByte();
            fileclass
= buffer.ToString();
            buffer
= r.ReadByte();
            fileclass
+= buffer.ToString();
        }
       
catch
        { 
            
        }
        r.Close();
        fs.Close();
       
if (fileclass == "255216" || fileclass == "7173"||fileclass=="6677"||fileclass=="13780")//说明255216是jpg;7173是gif;6677是BMP,13780是PNG;7790是exe,8297是rar
        {
           
return true;
        }
       
else
        {
           
return false;
        }
    }
}

评论
添加红包

请填写红包祝福语或标题

红包个数最小为10个

红包金额最低5元

当前余额3.43前往充值 >
需支付:10.00
成就一亿技术人!
领取后你会自动成为博主和红包主的粉丝 规则
hope_wisdom
发出的红包
实付
使用余额支付
点击重新获取
扫码支付
钱包余额 0

抵扣说明:

1.余额是钱包充值的虚拟货币,按照1:1的比例进行支付金额的抵扣。
2.余额无法直接购买下载,可以购买VIP、付费专栏及课程。

余额充值