Asp.net FileUpload+Image制作头像效果示例代码

在Web开发中会经常使用到个人信息注册，而个人信息中通常需要自己的头像或者照片。今天主要介绍一下使用FileUpload+img控件上传照片。

FileUpLoad控件使用介绍
FileUpLoad控件的PostedFile属性主要获取上传文件的一些基础信息。

.ContentLength
获取上传文件的大小。返回值为int类型，单位为字节。
用途
1、判断上传文件的大小
if (this.FileUpload1.PostedFile.ContentLength <= 4000000) //4M
{
Response.Write("<script>alert('" +FileUpload1.PostedFile.ContentLength + "')</script>");
}
else
{
Response.Write("<script>alert('太大了不能上传！')</script>");
}
其中FileUpload1是上传控件的ID，this.FileUpload1.PostedFile.ContentLength是上传文件的大小
2、修改ASP.NET上传的默认值
ASP.NET的默认最大上传值是4M，通过修改web.config，可以实现上传大文件：
代码如下:

<system.web> 
<httpRuntime maxRequestLength="4096"//这里的4096就是4m，原先是默认的。你改一下这个，就可以了。 
executionTimeout="3600" 
/> 
</system.web> 
 
.ContentType 
获取上传文件的MIME内容类型。PostedFile.ContentType这个属性通常用来判断上传文件的MIME类型，我们通常以此来拒绝某些类型的上传，比如仅允许上传图像文件，或者指定固定图片的格式。 

在net，做上传文件判断文件格式的写法总结： 
 代码如下:

".*"="application/octet-stream" 
".001"="application/x-001" 
".301"="application/x-301" 
".323"="text/h323" 
".906"="application/x-906" 
".907"="drawing/907" 
".a11"="application/x-a11" 
".acp"="audio/x-mei-aac" 
".ai"="application/postscript" 
".aif"="audio/aiff" 
".aifc"="audio/aiff" 
".aiff"="audio/aiff" 
".anv"="application/x-anv" 
".asa"="text/asa" 
".asf"="video/x-ms-asf" 
".asp"="text/asp" 
".asx"="video/x-ms-asf" 
".au"="audio/basic" 
".avi"="video/avi" 
".awf"="application/vnd.adobe.workflow" 
".biz"="text/xml" 
".bmp"="application/x-bmp" 
".bot"="application/x-bot" 
".c4t"="application/x-c4t" 
".c90"="application/x-c90" 
".cal"="application/x-cals" 
".cat"="application/vnd.ms-pki.seccat" 
".cdf"="application/x-netcdf" 
".cdr"="application/x-cdr" 
".cel"="application/x-cel" 
".cer"="application/x-x509-ca-cert" 
".cg4"="application/x-g4" 
".cgm"="application/x-cgm" 
".cit"="application/x-cit" 
".class"="java/*" 
".cml"="text/xml" 
".cmp"="application/x-cmp" 
".cmx"="application/x-cmx" 
".cot"="application/x-cot" 
".crl"="application/pkix-crl" 
".crt"="application/x-x509-ca-cert" 
".csi"="application/x-csi" 
".css"="text/css" 
".cut"="application/x-cut" 
".dbf"="application/x-dbf" 
".dbm"="application/x-dbm" 
".dbx"="application/x-dbx" 
".dcd"="text/xml" 
".dcx"="application/x-dcx" 
".der"="application/x-x509-ca-cert" 
".dgn"="application/x-dgn" 
".dib"="application/x-dib" 
".dll"="application/x-msdownload" 
".doc"="application/msword" 
".dot"="application/msword" 
".drw"="application/x-drw" 
".dtd"="text/xml" 
".dwf"="Model/vnd.dwf" 
".dwf"="application/x-dwf" 
".dwg"="application/x-dwg" 
".dxb"="application/x-dxb" 
".dxf"="application/x-dxf" 
".edn"="application/vnd.adobe.edn" 
".emf"="application/x-emf" 
".eml"="message/rfc822" 
".ent"="text/xml" 
".epi"="application/x-epi" 
".eps"="application/x-ps" 
".eps"="application/postscript" 
".etd"="application/x-ebx" 
".exe"="application/x-msdownload" 
".fax"="image/fax" 
".fdf"="application/vnd.fdf" 
".fif"="application/fractals" 
".fo"="text/xml" 
".frm"="application/x-frm" 
".g4"="application/x-g4" 
".gbr"="application/x-gbr" 
".gcd"="application/x-gcd" 
".gif"="image/gif" 
".gl2"="application/x-gl2" 
".gp4"="application/x-gp4" 
".hgl"="application/x-hgl" 
".hmr"="application/x-hmr" 
".hpg"="application/x-hpgl" 
".hpl"="application/x-hpl" 
".hqx"="application/mac-binhex40" 
".hrf"="application/x-hrf" 
".hta"="application/hta" 
".htc"="text/x-component" 
".htm"="text/html" 
".html"="text/html" 
".htt"="text/webviewhtml" 
".htx"="text/html" 
".icb"="application/x-icb" 
".ico"="image/x-icon" 
".ico"="application/x-ico" 
".iff"="application/x-iff" 
".ig4"="application/x-g4" 
".igs"="application/x-igs" 
".iii"="application/x-iphone" 
".img"="application/x-img" 
".ins"="application/x-internet-signup" 
".isp"="application/x-internet-signup" 
".IVF"="video/x-ivf" 
".java"="java/*" 
".jfif"="image/jpeg" 
".jpe"="image/jpeg" 
".jpe"="application/x-jpe" 
".jpeg"="image/jpeg" 
".jpg"="application/x-jpg" 
".js"="application/x-javascript" 
".jsp"="text/html" 
".la1"="audio/x-liquid-file" 
".lar"="application/x-laplayer-reg" 
".latex"="application/x-latex" 
".lavs"="audio/x-liquid-secure" 
".lbm"="application/x-lbm" 
".lmsff"="audio/x-la-lms" 
".ls"="application/x-javascript" 
".ltr"="application/x-ltr" 
 
.FileName 
获取上传文件的完整路径及名称。此路径为改文件所在在客户端文件中的路径。通常用这个属性来获取上传文件的名称并保保存。 
.FileUpload1.SaveAs 
将上传文件保存到指定路径的文件下。通常借助Server.MapPath（）方法保存文件到服务器指定文件下。（获取Web服务器指定虚拟路径相对应的物理文件路径） 
图片上传实例 
FileUpload+Image控件实现上传指定图片大小、格式、保存到指定路径文件下。 
.axps 
 代码如下:

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Fileup.aspx.cs" Inherits="Testcookie.Fileup" %> 
<!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></title> 
</head> 
<body> 
<form id="form1" runat="server"> 
<div> 
<asp:Image ID="Image1" runat="server" Height="180px" Width="191px" ImageUrl="~/Photo/untitled.png" /> 
<asp:FileUpload ID="FileUpload1" runat="server" /> 
<asp:Button ID="btnupload" runat="server" Text="Button" onclick="btnupload_Click<SPAN style="FONT-FAMILY: Arial, Helvetica, sans-serif">" /></SPAN> 
<asp:Button ID="btndelete" runat="server" Text="Button" onclick="btndelete_Click" /> 
</div> 
</form> 
</body> 
</html> 
 
.axps.cs 
 代码如下:

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Web; 
using System.Web.UI; 
using System.Web.UI.WebControls; 
namespace Testcookie 
{ 
public partial class Fileup : System.Web.UI.Page 
{ 
protected void Page_Load(object sender, EventArgs e) 
{ 
} 
protected void btnupload_Click(object sender, EventArgs e) 
{ 
int length= this.FileUpload1.PostedFile.ContentLength;//<SPAN style="COLOR: #ff0000">获取图片大小，以字节为单位</SPAN> 
if(length<4000) 
{ 
Response.Write("<script language='javascript'>alert('您选择的图片过大！');</script>"); 
} 
else{ 
String type=this.FileUpload1.PostedFile.ContentType;//<SPAN style="COLOR: #ff0000">获取上传文件类型</SPAN> 
String fullfilename = this.FileUpload1.PostedFile.FileName;//<SPAN style="COLOR: #ff0000">获取上传文件在客户端的路径及名称</SPAN> 
String filename = fullfilename.Substring(fullfilename.LastIndexOf("\\")+1); 
String extensions = filename.Substring(filename.LastIndexOf (".")+1);//<SPAN style="COLOR: #ff0000">获取文件扩展名</SPAN> 
string name=DateTime.Now.ToString("yyyyMMddHHmmss"); 
if (type == "image/jpeg" || type == "image/png" )//限制上传格式 
{ 
this.FileUpload1.SaveAs(Server.MapPath("Photo") + "\\" + name + "." + extensions);//<SPAN style="COLOR: #ff0000">将图片以当前时间命名保存，避免上传图片命名重复</SPAN> 
<SPAN style="COLOR: #ff0000">//设置上传图片大小为原图片大小</SPAN> 
//System.Drawing.Image img = System.Drawing.Image.FromFile(this.Server.MapPath("Photo") + "\\" + name + "." + extensions);//获得图片文件 
//int width = img.Width; 
//this.Image1.Width = width;//这是宽设置Image控件的宽度为图片宽度 
//int height = img.Height; 
//this.Image1.Height = height;//这是高，设置Image控件的高度为图片的高度 
this.Image1.ImageUrl = "Photo/" + name + "." + extensions; 
} 
else 
{ 
Response.Write("<script language='javascript'>alert('您选择的图片有误！');</script>"); 
} 
} 
} 
protected void btndelete_Click (object sender, EventArgs e) 
{ 
<SPAN style="COLOR: #ff0000">//删除图片</SPAN> 
if (System.IO.File.Exists(Server.MapPath("Photo")+"\\20130808084433.PNG")) 
{ 
try 
{ 
System.IO.File.Delete(Server.MapPath("Photo") + "\\20130808084433.PNG"); 
} 
catch 
{ 
throw new Exception("文件删除失败！"); 
} 
} 
} 
} 
} 
 
效果 
文件上传前 
 
文件上传后