Asp.net FileUpload+Image制作头像效果

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：

<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：

".*"="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

<%@ 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" />
        <asp:Button ID="btndelete" runat="server" Text="Button" onclick="btndelete_Click" />
    </div>
    </form>
</body>
</html>

.axps.cs

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;//获取图片大小，以字节为单位
            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;//获取上传文件类型
            String fullfilename = this.FileUpload1.PostedFile.FileName;//获取上传文件在客户端的路径及名称
            String filename = fullfilename.Substring(fullfilename.LastIndexOf("\\")+1);
            String  extensions = filename.Substring(filename.LastIndexOf (".")+1);//获取文件扩展名
            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);//将图片以当前时间命名保存，避免上传图片命名重复
               //设置上传图片大小为原图片大小
                //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)
        {
           //删除图片
            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