图片或者文件上传控件的使用

商品图片<asp:FileUpload ID="FileUpload1" runat="server" />
<asp:Button ID="Button1" runat="server" Text="上传" onclick="Button1_Click" />

<asp:Image ID="Image1" runat="server" ImageUrl="../upload/none.jpg"
ToolTip="none.jpg" Height="140px" Width="220px" />// ToolTip="none.jpg"   注 意很重要

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.IO;
using System.Net.Mail;
using System.Net;
namespace xh.shop.Utility
{
public class tool
{
/// <summary>过滤非法字符串
///
/// </summary>
/// <param name="value"></param>
/// <returns></returns>
public static string GetSafeSQL(string value)
{
if (string.IsNullOrEmpty(value))
return string.Empty;
value = Regex.Replace(value, @";", string.Empty);
value = Regex.Replace(value, @"'", string.Empty);
value = Regex.Replace(value, @"&", string.Empty);
value = Regex.Replace(value, @"%20", string.Empty);
value = Regex.Replace(value, @"--", string.Empty);
value = Regex.Replace(value, @"==", string.Empty);
value = Regex.Replace(value, @"<", string.Empty);
value = Regex.Replace(value, @">", string.Empty);
value = Regex.Replace(value, @"%", string.Empty);
return value;
}
/// <summary>上传文件方法
/// 返回文件名
/// </summary>
/// <param name="myFileUpload">上传控件ID</param>
/// <param name="allowExtensions">允许上传的扩展文件名类型,如：string[] allowExtensions = { ".doc", ".xls", ".ppt", ".jpg", ".gif" };</param>
/// <param name="maxLength">允许上传的最大大小，以M为单位</param>
/// <param name="savePath">保存文件的目录，注意是绝对路径,如：Server.MapPath("~/upload/");</param>
public static string Upload(FileUpload myFileUpload, string[] allowExtensions, int maxLength, string savePath)
{
// 文件格式是否允许上传
bool fileAllow = false;

//检查是否有文件案
if (myFileUpload.HasFile)
{
// 检查文件大小, ContentLength获取的是字节，转成M的时候要除以2次1024
if (myFileUpload.PostedFile.ContentLength / 1024 / 1024 >= maxLength)
{
throw new Exception("只能上传小于" + maxLength + "M的文件！");
}

//取得上传文件之扩展文件名，并转换成小写字母
string fileExtension = System.IO.Path.GetExtension(myFileUpload.FileName).ToLower();
string tmp = "";   // 存储允许上传的文件后缀名
//检查扩展文件名是否符合限定类型
for (int i = 0; i < allowExtensions.Length; i++)
{
tmp += i == allowExtensions.Length - 1 ? allowExtensions[i] : allowExtensions[i] + ",";
if (fileExtension == allowExtensions[i])
{
fileAllow = true;
}
}

if (fileAllow)
{
try
{
string datedir = DateTime.Now.ToString("yyyyMMdd");
if (!Directory.Exists(savePath + datedir))
{
Directory.CreateDirectory(savePath + datedir);
}
string saveName = Guid.NewGuid() + fileExtension;
string path = savePath + datedir + "/" + saveName;
//存储文件到文件夹
myFileUpload.SaveAs(path);
return datedir + "/" + saveName;
}
catch (Exception ex)
{
throw new Exception(ex.Message);
}
}
else
{
throw new Exception("文件格式不符，可以上传的文件格式为：" + tmp);
}
}
else
{
throw new Exception("请选择要上传的文件！");
}
}

}
}

protected void Button1_Click(object sender, EventArgs e)
{
try
{
string proimg = xh.shop.Utility.tool.Upload(FileUpload1, new string[] { ".jpg", ".gif", ".png" }, 2, Server.MapPath("~/upload/"));
//文件类型与大小保存路径

Image1.ImageUrl = "~/upload/" + proimg;
//预览路径
Image1.ToolTip = proimg;
}
catch (Exception ex)
{
Response.Write("<script language='JavaScript'>alert('"+ex.Message+"')</script>");

}
}