由于需要图片上传的功能,所以花了一些时间网上找相关资料终于搞定,效果图如下:
下面的是解决方案截图和上传的图片截图:
下面是代码:
1.界面代码
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<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="UploadPic.aspx.cs" Inherits="Pic_Try.UploadPic" %> <!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 >图片上传和显示</ title > < style type = "text/css" > .pic_text{ color:Red;} .pic_label { color:Gray; margin-top:5px; margin-bottom:5px;} .pic_image { margin:5px;} </ style > </ head > < body > < form id = "form1" runat = "server" > < div class = "pic_image" >< asp:Image ID = "pic" runat = "server" /></ div > < div >< asp:FileUpload ID = "pic_upload" runat = "server" />< asp:Label ID = "lbl_pic" runat = "server" class = "pic_text" ></ asp:Label ></ div > < div class = "pic_label" >上传图片格式为.jpg, .gif, .bmp,.png,图片大小不得超过8M</ div > < div >< asp:Button ID = "btn_upload" runat = "server" Text = "上传" onclick = "btn_upload_Click" /></ div > </ form > </ body > </ html > |
2.后台代码
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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!" ; } } /// <summary> /// 验证是否指定的图片格式 /// </summary> /// <param name="str"></param> /// <returns></returns> 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" , ".gif" , ".bmp" , ".png" }; //对上传的文件的类型进行一个个匹对 for ( int i = 0; i < allowExtension.Length; i++) { if (thestr == allowExtension[i]) { isimage = true ; break ; } } return isimage; } /// <summary> /// 创建一个指定长度的随机salt值 /// </summary> 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); } /// <summary> /// 返回加密后的字符串 /// </summary> 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; } } } |
3.最后防止上传大文件图片时报错,配置文件添加配置
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<? xml version = "1.0" encoding = "utf-8" ?> <!-- 如何配置 ASP.NET 应用程序的详细消息 --> < configuration > < system.web > < compilation debug = "true" targetFramework = "4.0" /> < httpRuntime executionTimeout = "240" maxRequestLength = "8192000" /> </ system.web > </ configuration > |
希望大家喜欢这篇文章。