asp.net下檔案上傳和檔案刪除的代碼

檔案上傳
HttpPostedFile postFile = Request.Files["imgFile"];
if(postFile.FileName!=String.Empty){
ex=postFile.FileName.Substring(postFile.FileName.LastIndexOf("."));
fileName= DateTime.Now.ToString("yyyyMMdd") + ex;
absPath=System.Web.HttpContext.Current.Server.MapPath("/img_ad/"+adTypeEn+"/";);

if(!System.IO.Directory.Exists(absPath)) System.IO.Directory.CreateDirectory(absPath); //上傳檔案，要檢查一下是否建立了相關目錄
postFile.SaveAs(absPath+fileName);
}

檔案刪除
string sqlFile="select ('/img_ad/'+Ltrim(Rtrim(compName))+'/'+Ltrim(Rtrim(fileName)))as adFile from adinfo where id="+sid;
object objAd=SqlComd.CreateSqlScalar(sqlFile);
if(objAd!=null){
string fName = Server.MapPath(objAd.ToString());
if(File.Exists(fName)) File.Delete(fName); //刪除檔案，別忘了檢查一下有沒有這個檔案
}