html 代码：
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default2.aspx.cs" Inherits="Default2" %> <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head id="Head1" runat="server"> <title></title> </head> <body> <form id="form1" runat="server"> <div> <table> <tr> <td style="vertical-align: top; 10%;"> <fieldset> <legend>选择图片</legend> <asp:FileUpload ID="FileUpload1" runat="server" /> </fieldset> </td> <td> <fieldset> <legend>预览</legend> <asp:Image ID="Image1" Width="100px" Height="100px" runat="server" Visible="false" /> </fieldset> </td> </tr> </table> </div> </form> </body> </html>
后台cs代码：
using System; using System.Collections; using System.Configuration; using System.Data; using System.Linq; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.HtmlControls; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.IO; using System.Xml.Linq; public partial class Default2 : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { if (IsPostBack) { var ctrl = Request.Params[Page.postEventSourceID]; var args = Request.Params[Page.postEventArgumentID]; OnchangeHandle(ctrl, args); } } /// <summary> /// 绑定文件选择变更事件 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> protected void Page_Init(object sender, EventArgs e) { this.FileUpload1.Attributes.Add("onchange", Page.ClientScript.GetPostBackEventReference(this.FileUpload1, "onchange")); } /// <summary> /// 文件选择变更事件 /// </summary> /// <param name="ctrl"></param> /// <param name="args"></param> private void OnchangeHandle(string ctrl, string args) { if (ctrl == this.FileUpload1.UniqueID && args == "onchange") { this.Image1.Visible = true; Session["UploadBytes"] = this.FileUpload1.FileBytes; this.Image1.ImageUrl = "~/Class1.axd"; } } /// <summary> /// 上传按钮事件 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> protected void btn_Onclick(object sender, EventArgs e) { //建立存储的目录 string directory = "Myfiles/"; //判断目录是否存在 if (!Directory.Exists(Server.MapPath(directory))) { //如果不存在，创建它 Directory.CreateDirectory(Server.MapPath(directory)); } //新文件 string newFile = Server.MapPath(directory + Guid.NewGuid().ToString() + ".jpg"); if ((Session["UploadBytes"]) != null) { byte[] buffer = (byte[])(Session["UploadBytes"]); File.WriteAllBytes(newFile, buffer); } } }
web.Config
<httpHandlers> <add verb="*" path="Class1.axd" type="Class1"/> </httpHandlers>
Class1.axd指向的cs代码：
using System; using System.Data; using System.Configuration; using System.Linq; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.HtmlControls; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Xml.Linq; using System.Web.SessionState; /// <summary> ///Class1 的摘要说明 /// </summary> public class Class1 : IHttpHandler, IRequiresSessionState { public Class1() { // //TODO: 在此处添加构造函数逻辑 // } public void ProcessRequest(HttpContext context) { //Checking whether the UploadBytes session variable have anything else not doing anything if ((context.Session["UploadBytes"]) != null) { byte[] buffer = (byte[])(context.Session["UploadBytes"]); context.Response.BinaryWrite(buffer); } } public bool IsReusable { get { return false; } } }