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.界面代碼
<%@ 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)//驗證是否包含文件
{
//取得文件的擴展名,並轉換成小寫
string fileExtension = Path.GetExtension(pic_upload.FileName).ToLower();
//驗證上傳文件是否圖片格式
fileOk = IsImage(fileExtension);
if (fileOk)
{
//對上傳文件的大小進行檢測，限定文件最大不超過8M
if (pic_upload.PostedFile.ContentLength < 8192000)
{
string filepath = "/images/";
if (Directory.Exists(Server.MapPath(filepath)) == false)//如果不存在就創建file文件夾
{
Directory.CreateDirectory(Server.MapPath(filepath));
}
string virpath = filepath + CreatePasswordHash(pic_upload.FileName, 4) + fileExtension;//這是存到服務器上的虛擬路徑
string mappath = Server.MapPath(virpath);//轉換成服務器上的物理路徑
pic_upload.PostedFile.SaveAs(mappath);//保存圖片
//顯示圖片
pic.ImageUrl = virpath;
//清空提示
lbl_pic.Text = "";
}
else {
pic.ImageUrl = "";
lbl_pic.Text = "文件大小超出8M！請重新選擇！";
}
}
else {
pic.ImageUrl = "";
lbl_pic.Text = "要上傳的文件類型不對！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" };
//對上傳的文件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>
/// 創建一個指定長度的隨機salt值
/// </summary>
public string CreateSalt(int saltLenght)
{
//生成一個加密的隨機數
RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider();
byte[] buff = new byte[saltLenght];
rng.GetBytes(buff);
//返回一個Base64隨機數的字符串
return Convert.ToBase64String(buff);
}
/// <summary>
/// 返回加密後的字符串
/// </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);
//對密碼進行哈希
string hashenPwd = FormsAuthentication.HashPasswordForStoringInConfigFile(saltAndPwd, "sha1");
//轉為小寫字符並截取前16個字符串
hashenPwd = hashenPwd.ToLower().Substring(0, 16);
//返回哈希後的值
return hashenPwd;
}
}
}
3.最後防止上傳大文件圖片時報錯，配置文件添加配置
<?xml version="1.0" encoding="utf-8"?> <!-- 如何配置 ASP.NET 應用程序的詳細消息 --> <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刷新顯示的源碼下載。
希望大家喜歡這篇文章。
