Javascript posting to VB.Net page multiple times
Greetings,
Upon a javascript button click, I'm using jquery to post to a url:
$(".optionClick").click(function () {
var caseOption = $(this).attr('title');
$.post("../tracking/RecordClick.aspx?page=gallery&item=" + caseOption);
});
On the page being called, I'm using the following vb.net code to retrieve the querystring variables and write them to a database:
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Not Request.QueryString("page") Is Nothing Then
Dim trackingPage As String = Request.QueryString("page")
Dim trackingIP As String = Request.UserHostAddress
Dim trackingItem As String = Request.QueryString("item")
Dim trackingDate As String = Date.Now().ToString("G")
Try
Dim conString As String
conString = ConfigurationManager.ConnectionStrings("SSFDBConnectionString").ConnectionString
Dim sqlCon As New SqlConnection(conString)
Dim cmd As New SqlCommand
Select Case trackingPage
Case "gallery"
cmd.CommandType = CommandType.Text
cmd.CommandText = "INSERT INTO UserTrackGallery VALUES ('" & trackingIP & "', '" & trackingItem & "', '" & trackingDate & "')"
cmd.Connection = sqlCon
If sqlCon.State = ConnectionState.Closed Then
sqlCon.Open()
End If
cmd.ExecuteNonQuery()
If sqlCon.State = ConnectionState.Open Then
sqlCon.Close()
End If
Case "products"
Case "search"
End Select
Catch ex As Exception
End Try
Response.Close()
开发者_高级运维End If
End Sub
In local development, this works perfectly for me recording one database write per button click. On the server however, each post generates anywhere from 1 to 7 database writes.
I've been searching for a solution for a couple of days to no avail. Any help is greatly appreciated!
------------------------------Update--------------------------------
I tried to simplify the process by creating a VB.Net page with only a single button:
<%@ Page Language="VB" AutoEventWireup="false" CodeFile="javascript.aspx.vb" Inherits="gallery_javascript" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
<script src="../Scripts/jquery-1.4.2.min.js" type="text/javascript"></script>
<script type="text/javascript">
$(document).ready(function () {
$.ajaxSetup({ async: false });
$(".optionClick").click(function () {
$.post("../tracking/RecordClick.aspx?page=gallery&type=click&item=XYZ");
});
});
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
<input id="Button1" type="button" class="optionClick" value="button" />
</div>
</form>
</body>
</html>
But the problem persists. Firebug reports "Aborted" and the page is called multiple times. I also tried this javascript:
$(document).ready(function () {
$.ajaxSetup({ url: '../tracking/RecordClick.aspx' });
$(".optionClick").click(function () {
$.ajax({ data: 'page=gallery&type=click&item=XYZ' });
});
});
Tried this also:
url = "../tracking/RecordClick.aspx?page=gallery&type=click&item=XYZ";
if (window.XMLHttpRequest) { // Non-IE browsers
req = new XMLHttpRequest();
try {
req.open("POST", url, false);
} catch (e) {
alert(e);
}
req.send(null);
} else if (window.ActiveXObject) { // IE
req = new ActiveXObject("Microsoft.XMLHTTP");
if (req) {
req.open("POST", url, false);
req.send();
}
}
Each of the javascript blocks above worked locally as intended but failed in the same manner with multiple DB writes and Firebug "Aborted" status.
If I call the url+querystring directly via the browser, everything works as expected.
Could this be related to a delay of some sort since it works locally? Thanks for the help thus far!
(Edit) Also tried using the full path url in the code above - no improvement.
I found a solution to my problem. It appears that the more recent versions of .Net prevent HTTP POST calls, but this is allowed for localhost (which is why it worked perfectly locally). HTTPWatch and Firebug both showed the .aspx page connection but no response returned. It appears as though the multiple calls were retry attempts to receive a response.
My solution was to create a web service:
Option Strict On
Imports System.Data.SqlClient
Imports System.Data
Imports System
Imports System.Net
Imports System.Text
Imports System.IO
Imports System.Web.HttpContext
Imports System.Web
Imports System.Web.Services
Imports System.Web.Services.Protocols
' To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line.
<System.Web.Script.Services.ScriptService()> _
<WebService(Namespace:="http://mywebsite.com/")> _
<WebServiceBinding(ConformsTo:=WsiProfiles.BasicProfile1_1)> _
<Global.Microsoft.VisualBasic.CompilerServices.DesignerGenerated()> _
Public Class RecordClick
Inherits System.Web.Services.WebService
<WebMethod()> _
Public Function RecordClick() As String
Dim trackingPage As String = ""
Dim trackingIP As String = ""
Dim trackingType As String = ""
Dim trackingItem As String = ""
Dim trackingDate As String = ""
With HttpContext.Current
trackingPage = .Request.Params.Item(0)
trackingIP = .Request.UserHostAddress
trackingType = .Request.Params.Item(1)
trackingItem = .Request.Params.Item(2)
trackingDate = Date.Now().ToString("G")
End With
Dim conString As String
conString = ConfigurationManager.ConnectionStrings("SSFDBConnectionString").ConnectionString
Dim sqlCon As New SqlConnection(conString)
Dim cmd As New SqlCommand
cmd.Connection = sqlCon
cmd.CommandType = CommandType.StoredProcedure
cmd.CommandText = "spInsertRecordClick"
cmd.Parameters.Add("@IPAddress", SqlDbType.NVarChar, 50)
cmd.Parameters("@IPAddress").Direction = ParameterDirection.Input
If trackingIP = "" Then
cmd.Parameters("@IPAddress").Value = DBNull.Value
Else
cmd.Parameters("@IPAddress").Value = trackingIP
End If
cmd.Parameters.Add("@CaseOption", SqlDbType.NVarChar, 50)
cmd.Parameters("@CaseOption").Direction = ParameterDirection.Input
If trackingItem = "" Then
cmd.Parameters("@CaseOption").Value = DBNull.Value
Else
cmd.Parameters("@CaseOption").Value = trackingItem
End If
cmd.Parameters.Add("@TimeDate", SqlDbType.DateTime)
cmd.Parameters("@TimeDate").Direction = ParameterDirection.Input
If trackingDate = "" Then
cmd.Parameters("@TimeDate").Value = DBNull.Value
Else
cmd.Parameters("@TimeDate").Value = trackingDate
End If
cmd.Parameters.Add("@ViewType", SqlDbType.NChar, 10)
cmd.Parameters("@ViewType").Direction = ParameterDirection.Input
If trackingType = "" Then
cmd.Parameters("@ViewType").Value = DBNull.Value
Else
cmd.Parameters("@ViewType").Value = trackingType
End If
cmd.Parameters.Add("@Page", SqlDbType.NVarChar, 50)
cmd.Parameters("@Page").Direction = ParameterDirection.Input
If trackingPage = "" Then
cmd.Parameters("@Page").Value = DBNull.Value
Else
cmd.Parameters("@Page").Value = trackingPage
End If
Try
If sqlCon.State = ConnectionState.Closed Then
sqlCon.Open()
End If
cmd.ExecuteNonQuery()
Catch ex As Exception
Finally
If sqlCon.State = ConnectionState.Open Then
sqlCon.Close()
End If
End Try
If sqlCon.State = ConnectionState.Open Then
sqlCon.Close()
End If
Return "Success"
End Function
End Class
This is the javascript I used to call the web service:
$.ajax({
type: "POST",
url: "../tracking/RecordClick.asmx/RecordClick",
data: "page=" + DMOriginatingPage + "&type=" + DMType + "&item=" + DMtitle
});
I had to add the following to the system.web section of the web.config:
<webServices>
<protocols>
<add name="HttpGet"/>
<add name="HttpPost"/>
</protocols>
</webServices>
It works perfectly now. I'm not very experienced in this area so there's probably a better solution for what I'm trying to do. However, maybe this will help someone else - took me two weeks to figure this out. :)
I would suggest tracing the problem.
1) Use Firefox + Firebug, open the NET tab and watch how many requests are sent.
2) Paste your AJAX URL in your browser's address bar and see what happens on the server. This way you are sure only one request is made.
Have you tried using the full path from the root of the site in the post call...instead of using the "../"?
Suspect code:
$(".optionClick").click(function () {
$.post("../tracking/RecordClick.aspx?page=gallery&type=click&item=XYZ");
});
try removing the ".." and replacing it with the actual path...I am suspicious that that could be causing your problem.
加载中,请稍侯......
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