ASP.NET上傳檔案對檔案型別的高階判斷

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.IO;

public partial class niunantest : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        string str = FileUpload1.PostedFile.ContentType;
        Response.Write("檔案型別："+str);

        string filename = "";

        FileExtension[] fe = { FileExtension.GIF, FileExtension.JPG, FileExtension.PNG };
        if (FileValidation.IsAllowedExtension(FileUpload1, fe))
        {
            string fileExt = System.IO.Path.GetExtension(FileUpload1.FileName).ToLower();
            Response.Write("
驗證通過！");
            //filename = "/Images/" + DateTime.Now.ToString("yyyyMMddHHmmss") + fileExt;
            //FileUpload1.PostedFile.SaveAs(Server.MapPath(filename));
        }
        else
        {
            Response.Write( "
驗證不通過，只支援以下格式的圖片：JPG,GIF,PNG");
            return;
        }

    }

    public enum FileExtension
    {
        JPG = 255216,
        GIF = 7173,
        PNG = 13780,
        SWF = 6787,
        RAR = 8297,
        ZIP = 8075,
        _7Z = 55122

        // 255216 jpg;

        // 7173 gif;

        // 6677 bmp,

        // 13780 png;

        // 6787 swf

        // 7790 exe dll,

        // 8297 rar

        // 8075 zip

        // 55122 7z

        // 6063 xml

        // 6033 html

        // 239187 aspx

        // 117115 cs

        // 119105 js

        // 102100 txt

        // 255254 sql

    }

    public class FileValidation
    {
        public static bool IsAllowedExtension(FileUpload fu, FileExtension[] fileEx)
        {
            int fileLen = fu.PostedFile.ContentLength;
            byte[] imgArray = new byte[fileLen];
            fu.PostedFile.InputStream.Read(imgArray, 0, fileLen);
            MemoryStream ms = new MemoryStream(imgArray);
            System.IO.BinaryReader br = new System.IO.BinaryReader(ms);
            string fileclass = "";
            byte buffer;
            try
            {
                buffer = br.ReadByte();
                fileclass = buffer.ToString();
                buffer = br.ReadByte();
                fileclass += buffer.ToString();
            }
            catch
            {
            }
            br.Close();
            ms.Close();
            foreach (FileExtension fe in fileEx)
            {
                if (Int32.Parse(fileclass) == (int)fe)
                    return true;
            }
            return false;
        }
    }
}

來自 “ ITPUB部落格 ” ，連結：http://blog.itpub.net/12639172/viewspace-623296/，如需轉載，請註明出處，否則將追究法律責任。

ASP.NET上傳檔案對檔案型別的高階判斷

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