(转)ASP.NET(C#)FileUpload实现上传限定类型和大小的文件到服务器

上传文件有两个主要的目的地,一个是服务器，另一个是数据库,ASP.NET内置了FileUpload这个上传控件,文本框显示用户选择的文件的全名.

其属性主要包括:

ContenLength:上传文件大小,单位:字节

FileName:文件名称

HasFile:是否选择了文件

例子:
测试环境.net 2.0(内有详细说明)

default.aspx

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>

<!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>无标题页</title> 
</head> 
<body> 
<form id="form1" runat="server"> 
<div> 
<asp:FileUpload ID="FileUpload1" runat="server" /><br /> 
<br /> 
<asp:Button ID="btnUpload" runat="server" OnClick="btnUpload_Click" Text="上传" /> </div> 
</form> 
</body> 
</html>

default.aspx.cs

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
    }
    protected void btnUpload_Click(object sender, EventArgs e)
    {
        Boolean fileOk = false;
        string path = Server.MapPath("~/upload/");

//判断是否已经选取文件
        if (FileUpload1.HasFile)
        {
            //取得文件的扩展名,并转换成小写
            string fileExtension = System.IO.Path.GetExtension(FileUpload1.FileName).ToLower();
            //限定只能上传jpg和gif图片
            string[] allowExtension = { ".jpg", ".gif", ".txt", ".xls" };
            //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 (fileExtension == allowExtension[i])
                {
                    fileOk = true;
                    break;
                }
            }
            //
            if (fileOk)
            {
                resultlbl.Text = "要上传的文件类型不对！";
            }

//对上传文件的大小进行检测，限定文件最大不超过1M
            if (FileUpload1.PostedFile.ContentLength > 1024000)
            {
                fileOk = false;
            }
            //最后的结果
            if (fileOk)
            {
                try
                {
                    FileUpload1.PostedFile.SaveAs(path + FileUpload1.FileName);
                    resultlbl.Text ="上传成功";
                }
                catch
                {

resultlbl.Text = "上传失败";
                }
            }
            else
            {
                 resultlbl.Text = "文件类型或者文件大小超出１Ｍ或者文件类型不对";

}

}
    }
}

前端界面：

服务器端目录：

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