如何使用JavaScript将数据发送回asp.net中的调用页面

Question

Here I'm opening a new window then i will do some operations and i want to send back the data to main from from child form

Main form:

var sURL = 'AnodizingLoadingPopupHelp.aspx' +
                         '?ProfitCenterCode=' + strProfitCenterCode +
                          '&LineCode=' + MachineID;

                var sFeatures1 = "dialogHeight: 240px;dialogWidth:280px;dialogLeft:40px;dialogTop:100px";

                window.showModalDialog(sURL, "Lookup", sFeatures1, true);

                var Receivedata = '<%= Session["data"] %>';
                alert(Receivedata );

Child form:

var senddata = data;
                '<%Session["data"] = "' + senddata + '"; %>';
                 alert(senddata);
                 window.close();

Here I'm using session but , I'm not able to get value in session , it says "undefined"

Answer 1

Traditionally, Query String is used to pass values like this.

protected void Page_Load(object sender, EventArgs e)
{
    string v = Request.QueryString["param"];
    if (v != null)
    {
        Response.Write("param is ");
        Response.Write(v);
    }
}

---

But in cases where Query String won't do, such as interfacing with some other application, it's best to use a HTML control that is set to hidden. Don't forget to account for cross browser issues :

function getElement (id) {
  if (document.getElementById) {
    return document.getElementById(id);
  }
  else if (document.all) {
    return window.document.all[id];
  }
  else if (document.layers) {
    return window.document.layers[id];
  }
} 

If you do not have a runat=server on the control, And get the control like this :

 myValue = getElement ("#myControlID").value;

Otherwise, if you did use the runat=server property on your control, then you can get it in javascript like this :

myValue= getElement('<%= HiddenStatusFlag.ClientID%>').value; 

( see here: Get Value of Hidden Field in Client Side )