1.最简单的单文件上传(没花头)
2.多文件上传
3.客户端检查上传文件类型(以上传图片为例)
4.服务器端检查上传文件类型(以上传图片为例)
5.服务器端检查上传文件类型(可以检测真正文件名)
6.上传文件文件名唯一性处理(时间戳+SessionID)
7.上传图片生成等比例缩略图
8.上传图片加水印(文字水印，图片水印，文字+图片水印)
9.
1.最简单的单文件上传(没花头)
效果图：
说明：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。
后台代码：
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;
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;
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！";
}
}
catch (Exception ex)
{
this.lb_info.Text = "上传发生错误！原因是：" + ex.ToString();
}
}
}
前台代码：
<table style="width: 343px">
<tr>
<td style="width: 100px">
单文件上传</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">
<asp:Button ID="bt_upload" runat="server" OnClick="bt_upload_Click" Text="上传" /></td>
</tr>
<tr>
<td style="width: 100px; height: 21px;">
<asp:Label ID="lb_info" runat="server" ForeColor="Red" Width="183px"></asp:Label></td>
<td style="width: 100px; height: 21px">
</td>
</tr>
</table>
2.多文件上传
效果图：
后台代码：
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;
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;
string filename = filepath.Substring(filepath.LastIndexOf("\\") + 1);
string serverpath = Server.MapPath("images/") + filename;
mypost.SaveAs(serverpath);
this.lb_info.Text = "上传成功！";
}
}
catch (Exception error)
{
this.lb_info.Text = "上传发生错误！原因：" + error.ToString();
}
}
}
}
}
前台代码：
<%@ 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>多文件上传 清清月儿http://blog.csdn.net/21aspnet/</title>
</head>
<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="183px"></asp:Label></td>
<td style="width: 100px">
</td>
</tr>
</table>
</div>
</form>
</body>
</html>
3.客户端检查上传文件类型(以上传图片为例)
效果图：
后台代码和1.最简单的单文件上传一样；
前台代码：
<%@ 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>清清月儿 http://blog.csdn.net/21aspnet</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 style="width: 343px">
<tr>
<td style="width: 104px">
文件上传判断</td>
<td style="width: 100px">
</td>
</tr>
<tr>
<td style="width: 104px">
<asp:FileUpload ID="FileUpload1" runat="server" Width="400px" />
</td>
<td style="width: 100px">
<asp:Button ID="bt_upload" runat="server" OnClick="bt_upload_Click" Text="上传" OnClientClick="return Check_FileType()"/></td>
</tr>
<tr>
<td style="width: 104px; height: 21px;">
<asp:Label ID="lb_info" runat="server" ForeColor="Red" Width="183px"></asp:Label></td>
<td style="width: 100px; height: 21px">
</td>
</tr>
</table>
</div>
</form>
</body>
</html>
说明：点击上传时先触发客户端事件Check_FileType；
4.服务器端检查上传文件类型(以上传图片为例)
效果图：
后台代码：
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;
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();
}
}
public static bool IsAllowedExtension(FileUpload hifile)
{
string strOldFilePath = "", strExtension = "";
string[] arrExtension = { ".gif", ".jpg", ".jpeg", ".bmp", ".png" };
if (hifile.PostedFile.FileName != string.Empty)
{
strOldFilePath = hifile.PostedFile.FileName;
strExtension = strOldFilePath.Substring(strOldFilePath.LastIndexOf("."));
for (int i = 0; i < arrExtension.Length; i++)
{
if (strExtension.Equals(arrExtension[i]))
{
return true;
}
}
}
return false;
}
}
5.服务器端检查上传文件类型(可以检测真正文件名)
其实方法4并不好，因为用户可以把XXX.txt伪装为XXX.jpg。
效果图：
后台代码：
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;
public partial class _Default : System.Web.UI.Page
{
//清清月儿 http://blog.csdn.net/21aspnet
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();
}
}
public static bool IsAllowedExtension(FileUpload hifile)
{
System.IO.FileStream fs = new System.IO.FileStream(hifile.PostedFile.FileName, System.IO.FileMode.Open, System.IO.FileAccess.Read);
System.IO.BinaryReader r = new System.IO.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")//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;
}
}
}
6.上传文件文件名唯一性处理(时间戳+SessionID)
效果图：
说明：年月日时分秒+临时session+原文件名 如果大家怕还会重复可以加GUID
