ASP.NET圖片上傳執行個體(附源碼)_實用技巧

來源:互聯網
上載者:User

由於需要圖片上傳的功能,所以花了一些時間網上找相關資料終於搞定,效果圖如下:

下面的是解決方案截圖和上傳的圖片截圖:

下面是代碼:
1.介面代碼

<%@ 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>圖片上傳和顯示</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">上傳圖片格式為.jpg, .gif, .bmp,.png,圖片大小不得超過8M</div> <div><asp:Button ID="btn_upload" runat="server" Text="上傳" onclick="btn_upload_Click"/></div> </form> </body></html>


2.後台代碼

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)//驗證是否包含檔案  {  //取得檔案的副檔名,並轉換成小寫  string fileExtension = Path.GetExtension(pic_upload.FileName).ToLower();  //驗證上傳檔案是否圖片格式  fileOk = IsImage(fileExtension);  if (fileOk)  {   //對上傳檔案的大小進行檢測,限定檔案最大不超過8M   if (pic_upload.PostedFile.ContentLength < 8192000)   {   string filepath = "/images/";   if (Directory.Exists(Server.MapPath(filepath)) == false)//如果不存在就建立file檔案夾   {    Directory.CreateDirectory(Server.MapPath(filepath));   }   string virpath = filepath + CreatePasswordHash(pic_upload.FileName, 4) + fileExtension;//這是存到伺服器上的虛擬路徑   string mappath = Server.MapPath(virpath);//轉換成伺服器上的實體路徑   pic_upload.PostedFile.SaveAs(mappath);//儲存圖片   //顯示圖片   pic.ImageUrl = virpath;   //清空提示   lbl_pic.Text = "";   }   else {   pic.ImageUrl = "";   lbl_pic.Text = "檔案大小超出8M!請重新選擇!";   }  }  else {   pic.ImageUrl = "";   lbl_pic.Text = "要上傳的檔案類型不對!請重新選擇!";  }  }  else  {  pic.ImageUrl = "";  lbl_pic.Text = "請選擇要上傳的圖片!";  } } /// <summary> /// 驗證是否指定的圖片格式 /// </summary> /// <param name="str"></param> /// <returns></returns> public bool IsImage(string str) {  bool isimage = false;  string thestr = str.ToLower();  //限定只能上傳jpg和gif圖片  string[] allowExtension = { ".jpg", ".gif", ".bmp",".png" };  //對上傳的檔案的類型進行一個個匹對  for (int i = 0; i < allowExtension.Length; i++)  {  if (thestr == allowExtension[i])  {   isimage = true;   break;  }  }  return isimage; } /// <summary> /// 建立一個指定長度的隨機salt值 /// </summary> public string CreateSalt(int saltLenght) {  //產生一個加密的隨機數  RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider();  byte[] buff = new byte[saltLenght];  rng.GetBytes(buff);  //返回一個Base64隨機數的字串  return Convert.ToBase64String(buff); }  /// <summary> /// 返回加密後的字串 /// </summary> public string CreatePasswordHash(string pwd, int saltLenght) {  string strSalt = CreateSalt(saltLenght);  //把密碼和Salt連起來  string saltAndPwd = String.Concat(pwd, strSalt);  //對密碼進行雜湊  string hashenPwd = FormsAuthentication.HashPasswordForStoringInConfigFile(saltAndPwd, "sha1");  //轉為小寫字元並截取前16個字串  hashenPwd = hashenPwd.ToLower().Substring(0, 16);  //返回雜湊後的值  return hashenPwd; } }}

3.最後防止上傳大檔案圖片時報錯,設定檔添加配置

<?xml version="1.0" encoding="utf-8"?><!-- 如何配置 ASP.NET 應用程式的詳細訊息 --><configuration> <system.web> <compilation debug="true" targetFramework="4.0" /> <httpRuntime executionTimeout="240" maxRequestLength="8192000"/> </system.web></configuration>

ASP.NET圖片自動上傳和局部重新整理顯示的源碼下載。

希望大家喜歡這篇文章。

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