ASP.NET图片上传实例（附源码）

 <%@ Page Language="C#" AutoEventWireup="true" CodeBehind="UploadPic.aspx.cs" Inherits="Pic_Try.UploadPic" %>   
 
上传图片格式为.jpg-600, .gif, .bmp,.png-600,图片大小不得超过8M

 using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using System.IO; using System.Security.Cryptography; using System.Web.Security; namespace Pic_Try { public partial class UploadPic : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { } protected void btn_upload_Click(object sender, EventArgs e) { Boolean fileOk = false; if (pic_upload.HasFile)//验证是否包含文件 { //取得文件的扩展名,并转换成小写 string fileExtension = Path.GetExtension(pic_upload.FileName).ToLower(); //验证上传文件是否图片格式 fileOk = IsImage(fileExtension); if (fileOk) { //对上传文件的大小进行检测，限定文件最大不超过8M if (pic_upload.PostedFile.ContentLength <8192000) { string filepath = "/images/"; if (Directory.Exists(Server.MapPath(filepath)) == false)//如果不存在就创建file文件夹 { Directory.CreateDirectory(Server.MapPath(filepath)); } string virpath = filepath + CreatePasswordHash(pic_upload.FileName, 4) + fileExtension;//这是存到服务器上的虚拟路径 string mappath = Server.MapPath(virpath);//转换成服务器上的物理路径 pic_upload.PostedFile.SaveAs(mappath);//保存图片 //显示图片 pic.ImageUrl = virpath; //清空提示 lbl_pic.Text = ""; } else { pic.ImageUrl = ""; lbl_pic.Text = "文件大小超出8M！请重新选择！"; } } else { pic.ImageUrl = ""; lbl_pic.Text = "要上传的文件类型不对！请重新选择！"; } } else { pic.ImageUrl = ""; lbl_pic.Text = "请选择要上传的图片！"; } } /// 
 /// 验证是否指定的图片格式 /// 
 ///  ///  public bool IsImage(string str) { bool isimage = false; string thestr = str.ToLower(); //限定只能上传jpg和gif图片 string[] allowExtension = { ".jpg-600", ".gif", ".bmp",".png-600" }; //对上传的文件的类型进行一个个匹对 for (int i = 0; i  /// 创建一个指定长度的随机salt值 ///  public string CreateSalt(int saltLenght) { //生成一个加密的随机数 RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider(); byte[] buff = new byte[saltLenght]; rng.GetBytes(buff); //返回一个Base64随机数的字符串 return Convert.ToBase64String(buff); } /// 
 /// 返回加密后的字符串 /// 
 public string CreatePasswordHash(string pwd, int saltLenght) { string strSalt = CreateSalt(saltLenght); //把密码和Salt连起来 string saltAndPwd = String.Concat(pwd, strSalt); //对密码进行哈希 string hashenPwd = FormsAuthentication.HashPasswordForStoringInConfigFile(saltAndPwd, "sha1"); //转为小写字符并截取前16个字符串 hashenPwd = hashenPwd.ToLower().Substring(0, 16); //返回哈希后的值 return hashenPwd; } } }