using system.io;

1.文件上傳
----------
如下要點：
html部分：
<form id="form1" runat="server" method="post" enctype="multipart/form-data">
<input id="fileupload" type="file" runat="server"/><br />
后臺cs部分 按鈕事件
//string strfilefullname = system.io.path.getfilename(this.fileupload.postedfile.filename);
//this.fileupload.postedfile.saveas(server.mappath("./xmlzip/") + strfilefullname);

2.文件下載
----------
listbox的selectedindexchanged事件 設定相關下載連接
    protected void lst_downloadfilelist_selectedindexchanged(object sender, eventargs e)
    {
        try
        {
            string strjs = "window.open('xmlzip/";
            strjs += this.lst_downloadfilelist.selecteditem.text.trim();
            strjs += "'); return false; ";
            this.imgbtn_downloadfile.attributes.add("onclick", strjs);
        }
        catch (exception ex)
        {
            ex.tostring();
        }
    }
或者也可以通過 改變label的text值 來實現點擊后實現文件下載的超級連接
this.label1.text = "<a href=/"xmlzip/a.rar/">a.rar</a>"

3.文件刪除
---------
string strfilepath = server.mappath("../countryflowmgr/xmlzip/"+this.lst_downloadfilelist.selecteditem.text.trim());
if (file.exists(strfilepath))
{
   file.delete(strfilepath);
   if (file.exists(strfilepath))
   {
 response.write("ok");
   }
   else
   {
        response.write("ok");
   }
}

4.得到文件夾下的文件列表
-----------
#region 得到當前可用的文件列表
    /// <summary>
    /// 得到當前可用的文件列表
    /// </summary>
    /// <param name="isalert">是否需要彈出提示信息</param>
    private void fn_getcurrfilelist(bool isalert)
    {
        try
        {
            //查找xmlzip文件夾下 屬于其本身unitcoding的相關zip文件
            string strxmlzipdirectory = server.mappath("../xmlzip/");
            if (directory.exists(strxmlzipdirectory))
            {
                //directoryinfo di = new directoryinfo(environment.currentdirectory);
                directoryinfo di = new directoryinfo(strxmlzipdirectory);
               
                fileinfo[] fi = di.getfiles("*.zip");//只查.zip文件
                if (fi.length > 0)
                {
                    lst_downloadfilelist.items.clear();
                    foreach (fileinfo tmpfi in fi)
                    {
                        listitem tmpitem = new listitem();
                        tmpitem.text = tmpfi.name;
                        lst_downloadfilelist.items.add(tmpitem);
                    }
                    lst_downloadfilelist.selectedindex = 0;
                }
                else
                {
                    if (isalert)
                    {
                        response.write("查無可以下載的文件!");
                    }
                }
            }
        }
        catch (exception ex)
        {
            ex.tostring();
        }
    }
    #endregion