Javascript 使用ajax与C#获取文件大小实例详解

<script language="Jscript">function chksize(){ var ticketType = "Oil"; var file1=document.getElementById("txtfile"); var v = file1.value; file1.select(); var realpath = document.selection.createRange().text; var input = "<Record><Type>TicketLoanResult</Type><TicketType>" + realpath + "</TicketType></Record>"; var objXmlHttp = new ActiveXObject("Microsoft.XMLHTTP"); objXmlHttp.Open("POST", "XMLHttpPost.aspx", false); objXmlHttp.Send(input); var returnXml = objXmlHttp.responseText; if(returnXml!=null) {  returnXml=parseInt(returnXml/1024/1024); } alert(returnXml);  return false; }</script> 

public partial class XMLHttpPost : System.Web.UI.Page{ protected void Page_Load(object sender, EventArgs e) { try {  XmlDocument xmlDocumenet = new XmlDocument();  xmlDocumenet.Load(Request.InputStream);  string type = xmlDocumenet.SelectSingleNode("descendant::Type").InnerText;  string returnMessage = string.Empty;  switch (type.Trim())  {  case "TicketLoanResult":   returnMessage = GetTicketLoanResult(xmlDocumenet);   break;  default:   break;  }  Response.ContentType = "text/xml";  Response.Write(returnMessage); } catch (Exception exceptional) {  //如果有返回信息（Xml格式）  string errorMessage = "<Error>" + exceptional.Message + "</Error>";  Response.ContentType = "text/xml";  Response.Write(errorMessage); } finally {  Response.End(); } } private string GetTicketLoanResult(XmlDocument input) { XmlNode item = input.SelectSingleNode("descendant::TicketType"); string ticketType = item.InnerText.Trim(); FileStream stream = new FileStream(ticketType,FileMode.Open); return stream.Length.ToString(); }}