I have a user control in my asp.net application that load it's data from cache. i want it's cache be updated when the value of a variable be changed so i put this code on page directive
<%# OutputCache Duration="1000" VaryByParam="none"
VaryByControl="visitIsAu" %>
it works fine when i change the value of variable in markup like this
visitIsAu="true"
but it doesn't work when the value is changed through code behind like this
visitIsAu="<%=this.CurentUser.IsAuthorizedToVisitFiltered%>"
the value of variable does not change so its cache is not updated.
does anyone know why this happen?
For some reason I've never trusted the way ASP.NET handles cache using markup settings or using "injected" server tags on the aspx files. I know it works but it's only easy to control on simple scenarios.
I always implement cache control, when using user controls, at code behind level and taking into consideration that page life cycle that may have some catches base on the level of controls I have a certain page.
We can have: ascx > aspx or ascx > aspx > master.
In your case you need to guarantee that CurrentUser is set prior to the load of your user control. Check that using debug.
Related
I'm developing an ASP.NET website. Sometimes some modules contain so few content that I present them inside a jQUeryUI dialog and communicate with the server via AJAX. I keep those contents inside a separate file and load them to a jQueryUI dialog according to the appropriate module.I was wondering if it's a good idea to have that content as a plain HTML elements instead of asp ones. Somehow I thought maybe this would reduce the overhead the conversion from asp elements to html elements can cause.
I'd allways go with the aspx Page, because a dynamic Page is more work at the beginning but in the end it almost ever saves time.
Specially when your not sure of the content that will be shown there, it is better.
And for the one reason i do it, is to have everything the same.
One style one way to code.
I'd say this is probably premature optimization. The overhead of an aspx page is in almost all cases negligible. I believe it's more likely that you will some day need to put dynamic things in that page, in which case you would have to convert the html file to an aspx, and change the url for your ajax dialog - which will cost time/money.
If you have aspx pages, or ascs user controls that you do not actually use/run any code, you can set the AutoEventWireup the EnableViewState, and maybe the EnableSessionState to false and stop the calling of the PageLoad and the rest functions and reduce the overhead. So on top of the controls you declare:
<%# Control AutoEventWireup="false" EnableViewState="false" ...
or for page:
<%# Page AutoEventWireup="false" EnableViewState="false" EnableSessionState="false" ...
The disable of the session is let the pages loads in parallel, the disable of the EnableViewState is reduce the size, the AutoEventWireup is reduce the callback hooks and calls.
In general you can use what ever you wish - if your pages can work, but if you like to keep it robust and easy to change or update, or add new functionality in the future, then use dynamic aspx pages.
Similar question: Master page and performance
I am receiving the following error message after an HTTP POST on an ASP.NET form hosted inside a UserControl:
Failed to load viewstate. The control tree into which viewstate is being loaded must match the control tree that was used to save viewstate during the previous request. For example, when adding controls dynamically, the controls added during a post-back must match the type and position of the controls added during the initial request.
Here's additional info:
I'm running .NET 4.5 RC
It's an Umbraco 4.7-based website
On my local dev machine the form works perfectly
This error only occurs on the staging server which has .NET 4.5 (only), MSSQL 2012 Express, IIS 7.5, Windows 7 (I know, it's not a real server yet, one day maybe...)
The server is not part of a web farm (or garden, tho that should be irrevelant)
The user control does render controls dynamically
I have applied all the latest service packs.
I have run out of ideas now! I have even restarted it and also performed a richual over the server involving a song and a special dance to no avail.
What is important when you are adding controls dynamically is on which event you are adding them.
If you added controls on events that occur after load, they will be part of the viewstate you send to the client.
You will have to add those controls again before LoadViewState is called.
If you run into cases where the decision of which controls to add is itself stored in the ViewState or the value of a control, then remember even before the ViewState is loaded, this data is available in Request.Params
Refer the asp.net page life cycle
I just added EnableViewState="false" to my page placeholder and its gone. Hope it works for u as well.
This Error Mainly Occurs during View state Change: From One Template To other Template like in case of Item Template, Edit Item Template, in Controls like Form View, List Views, Detail View, Grid View in ASP .net (all frameworks);
While Changing from control states say Item Template ---> Edit Template
the followings were going to alter
1) Controls will change (its ID & states)
2) Its Positions will change.
While Transformation of view if any post back occurs you will get Error as
Failed to load viewstate. The control tree into which viewstate is
being loaded....
if you are using separate control for data-binding like (button,link_button_Image_button events) you will get this error reported !
To avoid this error >>> Once state changes from one template to other within method you call data source binding ( Don't call during click or any post backing events ).
OK, so the answer is literally: "Set up a new server with all the same software as the last one and try again" and it works now.
I add "name" attribute with the same value as id, then this problem is gone.
<input type="button" id="extractBomInfoBtn" name="extractBomInfoBtn" value="Extract" class="button textonly" />
I had the same issue. This issue was at client end but it didn't occur in my local system.
After hours of googling, i had written EnableViewState="false" to my table tag in aspx page which has all the dynamic controls and then i removed all the viewstate variables and instead i created some hidden textboxes in the aspx page and accepted DB values into them in code behind and used them throughout my code. It then solved my problem.
But still, i couldn't figure out what was exactly the problem.
In my case I was manipulating the .Text property of a asp:Literal on page load which was causing the issue. In all other cases this never caused me a viewstate error but in this particular case I was changing the .Text value to an html element.
The following caused the error:
<asp:Literal ID="SvgIcon" runat="server" />
SvgIcon.Text = "<svg version=\"1.1\" id=\"Layer_1\" bla bla />"
I was able to resolve the error by adding EnableViewState="false" explicitly to the control:
<asp:Literal ID="SvgIcon" runat="server" EnableViewState="false" />
Check if you have the binding method of the control directly in your page load event. This can cause this problem.
You can add new PlaceHolder per UserControls
OR
You can set enableviewstate=false on the control , if you dont need viewstate
In my case I had a grid view with (OnPageIndexChanging) event
and when I click on a page nothing will happen until I click it twice!
I was refreshing the data source before setting new page index.
This is what I was doing wrong
grd.DataSource = data;
grd.DataBind();
grd.PageIndex = e.NewPageIndex;
This is the right way
grd.PageIndex = e.NewPageIndex;
grd.DataSource = data;
grd.DataBind();
This can happen if you override SaveViewState in your control but don't override LoadViewState.
So I actually ended up discovering that the list of entities I was binding to was not in the same order as the controls in ViewState! I'm still working thru a cleaner solution, but my code is working with ViewStateEnabled = true by having the method which reconstructs my dynamic controls (called from Page_Load) do it differently if !IsPostBack.
Ultimately, I will probably need to fix my sorting algorithm for my nested dynamic controls, but suffice it to say: if you are using the same pattern as I am, of using a List to generate/bind to dynamic controls, and that order is fluid or changing, try comparing Request.Params to find the keys that are relevant to your control hierarchy, and see if they match the order of your List. That solved my issue. Kudos to #nunespascal!
In short, I am dynamically generating all but one tab in an AjaxToolkit tab control, and then populating that with a couple layers deep of placeholders and regular controls (textboxes, dropdownlists, etc), so that's why it's complicated to get the order of everything correct.
Although this is very old question, I had visited this as I got the similar issue. But my issue was generated just because I have added a javascript code in Master page in head tag. That javascript code is reading a value of Session["KeyName"] ,
Code is like below -
$(document).ready(function () {
var allowOpenInNewTab = false;
allowOpenInNewTab = '<%# Convert.ToString(Session["AllowOpenInNewTab"]).ToLower() %>' == 'true';
if (!allowOpenInNewTab && window.sessionStorage.tabId != '1') {
alert("This page is not allowed to be open in another tab, sorry we can not load the page!!");
}
});
When I remove above code then everything was running smoothly but if I keep adding this part of code, it was giving this error of
Failed to load viewstate. The control tree into which viewstate is being loaded must match the control tree that was used to save viewstate...
Finally I found the solution like if I move my javascript code from head to just before the end of the body tag.
So solution that worked for me was moving javascript code (which is reading Session value from Server tags) to just before end of body tag.
i am using OutputCache on a ASP.NET Page. I set it programmatically like this in my Page_Load:
Response.AddFileDependency(cachefilepath);
Response.Cache.SetExpires(DateTime.Now.AddHours(12));
Response.Cache.SetCacheability(HttpCacheability.Server);
Response.Cache.SetValidUntilExpires(true);
Response.Cache.SetSlidingExpiration(false);
Response.Cache.VaryByParams["*"] = true;
Now the Page will be cached and this works fine. But i have one UserControl on the Page which shouldn't be cached. Is it possbile to disable Caching for this UserControl although the whole Page is getting cached?
The reason is that the output of this UserControl has two states and so can be different for each client according to his actions...
Response.Cache is per Web Page, you will have to manage the cache on the whole page based on the user control, in other words you will have to expire the page cache when your user control is dynamic, looks like in your case page output cache will not work well
or you can add VaryByControl and pass that control, ref: http://msdn.microsoft.com/en-us/library/hdxfb6cy.aspx
I am working in a CMS where we use tokens ( which is turned into a user control. Is there a way to add the user control into an attribute value for our template style?
example :
<div class="<$tokenName/$>" />
this currently outputs an encoded user control, which is then not parsed by IIS.
Short answer: this is not possible.
Longer answer...
It's not IIS's job to parse the control... that happens when IIS hands off the request to the ASP.NET engine. ASP.NET does a single-pass parse through your ASPX before the Page lifecycle even starts... this is why controls you delcare in the ASPX are available during the Init event. Whenever your CMS expands "$tokenName", you are far past the point at which ASP.NET is interpreting your markup.
If you're having trouble with that, here's a thought experiment for you: What happens when $token expands into a user control that has some other $token2 control embedded in it? And that control contains some other $token3? How many times are you going to try and parse/expand/interpret your markup?
I'm working on a project that has all its user controls registered in its web.config file (which seems very clean and tidy)
So far so good (here comes the problem) however I'm trying to dynamically create and add user controls to a page. These user controls fire events that need handling.
Ordinarily that wouldn't be a problem:
You just register the control in the page, load the control, cast it to the correct type, and assign the event handlers, add it to the page, sit back and let the magic happen, easy peasy.
But I can't reference the control's type when the control is registered in the web.config, which means no cast, which means no event handling!
Weirdly you can reference the type if you add the usercontrol to the page at design time!
There must be a way round this (without having to register the control on the page, or add a control at design time), what on earth am I missing?
It's been a while, but I think I've seen this type of behavior in ASP.NET when a project is a Web Site and not the Web Application. As far as I remember, the Web Site compiles each page into its own assembly and with no common name space and regardless of config requires the <%# Register %> directive. If you don't, you get the exact error of missing an assembly reference.
I would have to test to be sure...
By saying : "you can reference the type if you add the usercontrol to the page at design time"
Do you mean it adds an <%# Register %> Directive at the top of the page ?
Or maybe, it adds a using / Imports (depending on you using c# / vb.net) clause in your source document ?
Because, to be able to cast to your control type, you normally need to import the namespace in the codebind. Maybe this is just what is missing.
The <controls> section in web.config and the <%# Register %> directive are the same thing (with the small exception that entries in web.config apply to the whole application). They allow you to add design-time controls to a web form.
If you want to add controls to a page dynamically, use the LoadControl function to get an instance of your control. Given a control with a class name of "Header", the following will load a control, set a property, and add the control to the form named, "form1":
Dim head As Header = LoadControl("~/Controls/Header.ascx")
head.Text = "Some text..."
Me.form1.Controls.Add(head)