Page_PreRender Fires Twice On First Load In Session?
Apr 29, 2010
When I run the web application, I notice that Page_PreRender is fired twice. This only happens the first time in a new session. It does not happen if I refresh the page, or on postbacks. I use .NET framework 3.5 and the built in ajax functionality.
The problem is not related to img tag with empty src attribute (which I have seen other posts with similar problem has mentioned). I know this because I see this in both FireFox and IE. The posts I saw about this stated that this was not a problem in IE. I have also searched and found no img tags with empty src in the generated page source, so it should not be this. I have also made a simple test page where I have included some of the functionality, and this does not happen.
Note: It is the entire page cycle that is firing twice, not just render.
I can't figure out why, but before my form is even displayed, the CheckChanged event fires. I don't even have a chance to check anything. Has anyone seen anything like this?
I have a script manager and 3 update panels on my page. I am not very familiar with AJAX but I would think anything in the contentTemplate would not cause a postback and page reload, but they all do, here is the outline of the SM and UpPanels
In my page without using updatepanel page open firsttime it fires only single time, after using updatepanel page load fires twice firsttime page open.. how to solve it.
We have an MVC.NET application that encounters fatal errors when it restarts. In our Session_Start event handler, we add the session id to a dictionary. In the Session_End handler, we remove it. Consider the following sequence of requests:
GET home.mvc <application restarts> GET main.css GET banner.jpg GET somedata.mvc ...
Because of the way the application is architected, this sort of sequence happens fairly frequently if you do a rebuild while the application is open in a browser window. That wouldn't be terribly concerning except that I see it in production environments too. For example, it will occur (albeit rarely) when you edit web.config.
The requests following the restart are all due to links in the home page or AJAX calls from JavaScript.
What I observe is that .NET handles the first 5 requests in parallel. Each such request causes it to fire the Session_Start event. After a short time, it fires the Session_End event 3 times. To be clear, each Session_Start corresponds to the exact same session. They all have the same session id and the IsNewSession property is true for all session state objects. Also, the Session_End events do not correspond to the session being killed. The session persists, along with any data stored in session state.
I need to either prevent it from firing Session_Start more than once or figure out how to tell when Session_End doesn't really mean that the session has ended.
I have noticed that when I have a session that has expired, the Session_OnStart event fires with every new request.
I suppose that this behavior is not normal, because I was expecting that the session would re-start only with the first request and not with every subsequent request.
This behavior occurs only with sessions where the timeout period has been exceded.
The current conditions under which I have experienced this problem are:
I have experienced this problem with an application that is using the .NET 2.0 framework and with a session mode configured to InProc. This problem is happening both on Windows XP SP3 and Windows 2003 Server.
I added the following code to global.asax to load up several session variable when a session starts. I'm assuming that when a page goes to use the variable that I should be
1) checking at the page level that the value is valid not 0 when its not expected to be 0, not a zero-length string when its expected to have a length
2) have code at the page level that sets the values if the values have not been set as when the Session timeout, ideally putting the code in a class derived from Page and then deriving all of my pages from the new class so that the code does not have to be repeated in every page
In my web form, i have 2 drop downlist controls. eg. dropdown1 and dropdown2. I will change the dropdownlist1 item, consequently selectedindexchanged event fires and reloads the dropdownlist2 items. And i have another button also in order to get the result based on the dropdown1 and dropdown2. Lets say for example, i have a list of countries in dropdown1 and a list of states in dropdown2. I selected "India" in dropdown1 and correspondingly "Tamilnadu" in dropdown2. And then click a button which calls the dataset based on dropdown1 and dropdown2. The problem i face here is, whenever i click on the button to load the dataset, dropdown1 value remains the same as the dataset is not called again, whereas the dropdown2 value changes to the first one as it gets called automatically during postback. For your information, I have loaded both the lists in the page load using (!IsPostback) property.
How do I create a new event in a base page class that fires after all derived pages have fired their load events but before any controls fire their load events.
The following code fires the event before the derived page's load event. I want it to fire the event after the derived page's load event but before all control load events:
Base Class:
Public Event FirstLoad(ByVal sender As Object, ByVal e As System.EventArgs) Private Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load If Not IsPostBack Then RaiseEvent FirstLoad(sender, e) End If End Sub
Derived Class:
Private Sub Page_FirstLoad(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.FirstLoad 'Stuff here happens before controls load but only on first page loads' End Sub
Currently in an .aspx file, I am storing a value (filename that was created in that session) in an hidden text box. When the user clicks on the "Print" labeled Hyperlink control, it opens the file that was stored in the hidden text box control. But when the user goes to different screen (in the same session), I loose the filename value that is stored in the hidden text box control. So I would like to store the filename variable in a session variable. So that if the user leaves this .aspx file and comes back to this .aspx file I can load the value into the hidden text box from the session variable.
Is there a way you can call a function, or make a file that runs before every page load. I want to be able to check if they have a valid session before showing the page.
What I have is a simple treeview with one root node, and some childnodes under it. My form allows users to add a new child under the parent, (I'm not pulling anything for the treeview from a database or anything - it is just a treeview with some static nodes). What I then need to be able to do is when navigating away from the page, and then coming back, I want the user added nodes to persist.
I would like to pass the treeview info to a Session variable and then upon page return load that session back into the treeview.I've tried to loop through the treeview to get all the nodes, but my count always comes out to 1, which I'm assuming is my root node. Do I just need to pass that to a session and it'll gather all the nodes under it as well, or do I need my session to be an array and load each node.
We have three web servers in our web farm that are load balanced using the Network Load Balancing Manager in Windows 2003. The sites that run on these boxes use In-Proc ASP.NET session. Our assumption is that the balancing uses a "sticky" session because users seem to be assigned to a given server during their use of the application as well as there doesn't appear to be any session error where the session data is residing on a previous machine. My question is how can I 1) verify that our balancing configuration is using "sticky" sessions and 2) can someone explain the load balancing feature in Windows 2003 relative to ASP.NET web applications?
My website/application is in ASP.NET. I use the traditional Session object when people connect so they have their preference, etc. My problem is that sessions were lost very often. I discovered that my hosting company was using load balancing on their servers, so one request on my website can be on one server, and the other on another one.
I tried to store the session data in a SQL Server database, but I quickly discovered that I can't create the needed database on my shared server because I only have one database in my package. Also, there is no guarantee that the rest of the script would have been able to run.
My questions: is there any other way to get around this problem? Should I buy another database only for this? Is there another type of session that I could use? Is there anything else I can use instead of session to keep track of my user when they are connected on my website?
Situation:In Web.Config we have CustomErrors turned on with redirectMode="ResponseRewrite".In Page_Load of our MasterPage we access the Session property of the Page.
Problem:When an Error occurs on any page the user gets redirected (via Rewrite) to our Error.aspx Page. There in the Page_Load of the MasterPage we access the Session and get an HttpException telling us to enable SessionState. But we have the SessionState enabled, definitly.
Question:How can we access the session after a UrlRewrite in the Page_Load Event of our MasterPage?
I'm using the beta version of Visual Studio 2010. I'm running my ASP.NET 4.0 website through the debugger. Whenever there is a page load (e.g. clicking on a link, a postback) the session is ended and a new session is created. This wipes out all the session variables and makes debugging impossible. How to get session variables to persist across page loads?
Is this problem unique to running ASP.NET in a test environment or unique to the beta 2 version of VS 2010?
We are currently running an asp.net application with 3.5 framework, using a SQL 2008 back-end. We have found that when we go from http to https we lose our session. Basically you come in on Server01 in http, add an item to your cart go to the secure checkout page (https) and you are now on Serve
How to open a popup image on page load in asp.net ? and can its possible that when i close the popup it should not open whan the session value is not end.
i want to do with the grid. first is how can i remove the row whenever the hit button fires up. Note that it will only remove the row in the grid and not deleting the entry. Second, when the Update button fires up I need to update all rows in the grid and set value of Status column to the row dropdownlist value.I'm thinking of adding another button inline with the row instead of doing a batch update. Would you think it would be convenient design in terms of net traffic?
I've got a simple ASHX handler that returns an dynamically generated image; the image is generated from a custom created class, and an object belonging to this class is passed to the handler using Session (I'd rather avoid using QueryString).The handler is used as the URL of an image on a ASP form which is very simple: a drop down list, a button and an image. Basically, depending on what the user selects from the list, the appropriate image will be generated once the button is pressed.
At the start the actual image has it's Visible property set to false; I don't want the handler to display anything before the data is all there.Once the button is pressed, the required Session parameter is added containing the necessary object, and the page is refreshed using Server.Transfer. When the Page_load method detects that the Session parameter has been correctly set, it sets the Visible parameter on the image to true.After that the handler fires up and generates the image.
So far so good... However, if the user now picks something different from the list and presses the button, despite the correct object being passed in the Session, the image won't be updated. In fact, the handler won't even fire up (if I put a breakpoint in there). I need to close the browser window and reopen it for it to work.Any ideas what could be the cause of such behaviour?I suspect the answer is very simple, and I just don't know something fundamental about ASP (or handlers)...
I have a program which listerns to a specific directory and do some stuff once file is created on that directory. The thing is this works perfectly fine when I run it manually for testing. Meaning that when I copy and paste files in to that directory it work just fine.
Then I test it against our business system and had this problem. When our business system generates a file in that directory event fires 2-3 times and this leads to lof of problems.
I have a comparevalidator which is used for a textbox. This comparevalidator supposed to work when user clicks submit button. But it fires on the second try. Here is the code.
[Code]....
Here is the vb portion
[Code]........
The problem is validatorcalloutextender fires when i click this Button_OK twice.
