This is 10KB in my HTML source:
<input type="hidden" name="__VIEWSTATE" id="__VIEWSTATE" value="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" />
This represents ~50% of the entire size of the page.
Why does it do this, why so long? Can I do anything about it? It's bad for mobile users.
What is this view state anyway and how to mitigate its size
In Asp.net WebForms every control saves its state because HTTP protocol is stateless and Asp.net WebForms pages bypass that by saving every control's state in this Base 64 encoded string. This is the only way for Asp.net framework to know whether some control's value has changed or not. But... This automatically means that static controls that don't get POSTed back to server (like label for instance) don't need to save their state. You can always set their EnableViewState="false".
Unfortunately this can't be set without any other code changes on other controls, that do get POSTed back (every server-side control that renders some sort of an input in HTML). This basically means that setting EnableViewState="false" on page level (within #Page directive) will have consequences that are seen as controls loosing their values, controls not firing certain events etc.
So, the more server-side controls you have the larger it will get (without turning it off on certain controls).
But I wouldn't worry if its size is 10k. That will go back and forth rather fast and painless. You will have problems when it gets much larger. I once worked on a project and we had an issue with a certain page (done by less experienced developer) where view state grew over 1MB. Imagine that. What a slowdown!
How to turn it off completely on page level
When you turn view state off on page level you have to be aware that certain controls that were loaded (or better said data bound) in on of your page's events, will have to be reloaded each time your page gets POSTed back at server. Otherwise they will show up as empty when your page gets back to the client.
Your server controls are filling the ViewState with data they will need on postback. If your page does not postback you can just disable the ViewState for the page.
To disable ViewState for the page you can just add EnableViewState="false" to the #Page directive. Please be aware you should only use this as a solution if you are 100% sure the page does not postback.
You also might want to check this MSDN article to get a better idea of what the ViewState does.
Disable viewstate for static controls, like a gridview.
Check out this question for more info:
If you are concerned about the viewstate on the client side, then think about storing it on the server side. Perhaps in a session variable. Take a look at this article as there is statistical comparison given. Download the solution and check out how to store it on the server side.
An Analysis of Keeping ViewState out of the Page
This article explained it neatly to me in the past: Taking a Bite Out of ASP.NET ViewState.
Basically viewstate's on by default and, depending on which controls you use, it can get out of hand pretty fast. Especially data controls like the gridview are responsible for massive injection of viewstate. You can disable that on a per control basis by setting the EnableViewState property to false. Be careful however as taking out viewstate might also take out functionality of the controls. So do it one by one and test test test.
Another way, and likely better for mobile, is to make use of ASP.NET MVC instead which doesn't have to deal with automatic viewstate injection.
Related
I understand the use of View state. Any material that talks about view state, explains the need and use of it. However there is an option provided at every control level/ page level to disable it as well.
In what circumstances we might want to disable the viewstate of a page or control?
From an online material, I read that,
If the page doesn't have any dynamic data, data to be persisted
between round trips we can disable viewstate.
I agree to this statement, but what's the advantage of doing this? What do we get out of it?
Some pages have HUGE viewstates. As such it takes time to send back and forth, its more load on the server, more network traffic, etc. There's no need for it a lot of times, so your apps will be quicker by shrinking your viewstate.
Take note even fully disabling viewstate at times will generate still a small required viewstate because of control requirements, but it can be greatly reduced. I've seen viewstates go into 200kb per page.
You get less payload since the ViewState hidden value gets set to "". In datagrids displaying several thousands of records, the ViewState can become several MB in size
Performance is improved not only because the ViewState is not transferred anymore, but also because reading ViewState is typically an expensive operation since it involves decrypting it and deserializing the value.
Actually, you can improve performance just by disabling the encryption of the ViewState but this is not a good security practice.
As the page has to render the ViewState to the client it can speed up load times if the ViewState is disabled.
Around the time that .Net was introduced I remember trouble shooting a page that was loading slowly, the page was rendering a sizeable grid all of which was been saved into ViewState. Removing the data from the ViewState made a big difference.
ViewState is rendered as a hidden input field in the web page. This makes the page load more slowly, and also makes post backs slower, since the ViewState must be posted along with everything else.
Therefore, your page will perform faster if you disable ViewState. How much faster? Hard to say.
In general, if you don't need ViewState, disable it.
Note also that even if you disable ViewState, there will still be a hidden control with a small amount of data that is neccessary for .NET.
When I display info or error messages to the user as asp:Label or asp:Literal controls, I almost always set EnableViewState to false, because they almost always apply only to a given post-back. Setting EnableViewState to false means I never have to write this in my code-behind:
lblSomethingWentWrong.Text = string.Empty;
I have a couple of pages that are bulky due to the viewstate. I have following question:
is there any tool that can track viewstate of individual control on page and tell me which control is taking maxm viewstate
also can i know which controls viewstate is not being used and disable it?
There are some Viewstate Utilities listed here http://blogs.msdn.com/rextang/archive/2007/05/25/2868250.aspx. I always store Viewstate in the database rather than send it back and forth over the internet. Example Code here http://www.componentworkshop.com/blog/2009/06/27/advanced-net-storing-viewstate-in-a-database
You can turn on trace on the page and that should show how much viewstate is used for each control.
I have no good answer to your second question, but one rule of thumb I use when i develop webforms is that i set EnableViewState=false immediately after I've created an Ascx.
That way I can turn it on when I actually need it and not wonder if my databound controls uses alot of viewstate.
For example,
If I have a textbox with runat=server on a page, The value will be posted back to the server so I can access the properties in the code-behind.
However, under the following situations, does it still hold true?
A textbox with runat=server but does not appear in the function that is post back to. For example, a button is also on the page, when clicked a post back occurs and within the method that is raised, this textbox was not used.
Within a MasterPage, will a textbox residing on the Masterpage itself be posted back?
Because just thinking, isn't this mechanism bloated in nature?
If all input controls and its value are posted back on every single button click (even when the input control is not needed), doesn't this deteriorate performance?
Having just one Form Tag on the page really restricts us to using this mechanism?
Truly Understanding ViewState is a must read article on the subject of ASP.NET ViewState
There are several options to cut down on the bloat (and yes, there's a lot of it when dealing with lots of controls):
Use AJAX to post only the items required - although be careful to allow clients that don't have JavaScript enabled to still use the page/ site.
The MVC framework allows multiple form tags to be used so you can group sections if needs be.
Set the EnableViewState to false on pages/ controls.
Break up your pages into smaller ones.
Additionally, check out this brilliant graphical representation of the Page Life Cycle in ASP.NET.
Every input on the page is posted back fully unless you use ajax, because of the single form tag. Welcome to asp.net...
As long as the method that you're hitting on the server-side is a non-static member of the page's class, it'll have access to the textbox and all other controls on the page.
And yes, all controls rendered to the browser (whether in the MasterPage, user control, etc.) will be available on post-back.
You may want to look into Understanding ASP.NET View State.
There surely are performance hits with this architecture, but (depending on complexity of the page) it's usually not an issue from the server load perspective, because hardware upgrades are typically cheaper than additional programming hours spend on optimizing application performance.
With that said, (and as others have pointed out) look into using AJAX if you want to avoid whole page-level postbacks to the server.
Yes, it's all posted back, and yes it can cause bloat. I'm sure if you search for ViewState you will find plenty of people ranting about it and how to minimise it :)
Yes your text box will be available in both cases, yes it is bloated. This is where AJAX comes into play. Using AJAX you can send just the data you need.
If you want to send a minimal ammount of data, you could use a Page Method (static method on page decorated so the script manager builds javascript to call it or you could call it using jquery or other methods), or a script enabled web service works nice as well.
You also have viewstate which can get very large. ASP.Net MVC is a new paradigm instead of using WebForms which doesn't have view state, or post backs. It embraces HTTP instead of hidding it giving developers more control.
The textbox data would be posted back as noted. In addition to using Ajax, disabling view state greatly imporoves your page's performance though even then data in properties critical to the functioning of controls (Control state) would still be posted back.
If you didn't have postback for every control on the form, you wouldn't be able to access it in code-behind. I.e. if in your button press you wanted to modify the property of the text control you couldn't do that because ASP.Net would know nothing about the text control.
Since the communication between the server and the client is stateless and every time a page is server the server forgets all about it Postbacks are important if you want to work with the same page again. No matter what programming language you use, this or similar mechanism exists for processing server side code.
If you wish to minimize postback (viewstate size), do this.
Set enableviewstate=false on all controls that you don't want posted back.
Use AJAX and web services wherever possible (and don't use UpdatePanel).
Use HTML control as much as possible instead of ASP.Net controls.
Hmm.. There are some excellent suggestion in other answers and good links too.
You've pretty much hit the nail on the head with vanilla ASP.NET - it's not very good! In both the instances you describe the answer is yes - the textbox will be sent with the form.
The whole postback/ViewState problem is a bit of a pain, one of the first things any competent ASP.NET developer learns to do is avoid them!
With user controls on a page, I understand that every control has an impact on memory usage by storing their own state in ViewState. My question is, how much?
For example - I have a feedback form as a control on my masterpage. It is set to Visible="false" by default. A user clicks on a feedback button, and the control becomes visible while it's needed.
What would would be the relative performance impact by having control sitting there on everypage (as it's located in the masterpage), but not visible? The site I'm developing will potentially have large amounts of traffic and I wonder if I'm setting myself up for a headache later on if things become slow.
Thanks
Performance could be impacted on the server and the client. Primarily you want to reduce the amount of HTML including viewstate that is sent to the client. If this sits on every page then you will send this viewstate information more often than you really need to.
I think you should have some logic that ensures that the feedback form control is only added to the feedback page. Rather than use visible="false", put it on it's own page and link to it, or dynamically add the control to the page.
The main benefits will be reduced bandwidth usage, and faster rendering of the page on the client. Secondary benefits include easier debugging and cleaner code rendering to the client.
With all performance problems you should be testing performance and making judgments based on hard data. In this case work out the size of the viewstate on the client, then multiply by number of requests to see the size of bandwidth usage on the server. On the client use a tool like FireBug to understand the overall page size received by the client.
It depends on the control. Datagrid with hundreds rows might generate 100k of viewstate. On the other side, checkbox won't generate too much.
You can just drop your feedback form control on empty aspx page, visit it in the browser and check for __viewstate hidden field. This is how much will you feedback form will add to each page in terms of viewstate. Then you will have to decide if it is acceptable.
I wouldn't htink about such an optimizations right at the start. If it will become slow later on, you can always change the form to be pure html and use ajax or something to post it data to server. As long as it is user control and not copy pasted content it will be easy to optimize
I am moving from classic ASP to ASP.NET and have encountered what many of you already know as "viewstate". I might be jumping the gun with my assumption, but it looks highly cumbersome. I have developed many ASP forms in the past and never had issues with keeping state. Is there another way OR am I going to have to learn this Viewstate thing in ASP.NET? I am using Visual Studio 2008, VB.NET as the code behind language and Framework v3.5 with SQL Server 2005.
You don't have to. Check out MVC framework. It eliminates ViewState and works as old ASP (at least from this point of view).
This series of posts is must reading for understanding ViewState
I disable it and do most of my work in Page_Init instead of Load (values are still maintained because of ControlState). This setup has worked out well for me.
ViewState is optional, but helpful. What ViewState is, is all the changes which occur on a control on the SERVER SIDE. So, if you're assigning text to a label, and you want that text to persist without the need to reassign it on every postback, then you'll want to maintain that. Another example where I always leave ViewState on is anything databound.
That said, there are times when it's helpful to turn ViewState off for that same reason. For example, the one place where I always turn ViewState off is a MESSAGE label. That way, when I have to print out a message to the user (one which should only appear once and then go away) I just add the text to the label and then forget about it. During the next PostBack, the label will automatically revert to the text which is found in the ASPX declaration for that control (in this case an empty string).
Now, note that this has nothing to do with the form collection, which are the values posted to IIS during the PostBack. The form collection sends the values that the user enters into form elements (textboxes, checkboxes, droplists,etc). These .NET will populate into the appropriate place--and this occurs AFTER ViewState has been processed.
This way, if you send a textbox with the phrase "hi there" to the client, the user changes it to "See ya" and then submits the form, what the textbox will have by the time the Page_Load event fires is a textbox with "See ya" in the TEXT attribute.
In classic ASP we always just used a HIDDEN field to do the job. Viewstate is just a way of doing that for you automatically. Trust me the learning curve is not as high as you might think.
Some controls are deeply crippled when you turn ViewState off, so be prepared to address these concerns. It's easiest to just be lazy and leave it on, but left unchecked, ViewState can easily account for 30% of the size of your HTML.
For example, say you have a DropDown, and you bind it to a list of Fruits. You bind it in the if(! IsPostBack) { } block in the page load. If you turn off ViewState, you'll lose the items when you click a button. They need to be bound every page load. You'll also lose your selected index, so you'd need to pull that off of the Request.Form[] variables.
Viewstate is part of the package when you are working with ASP.NET. For a basic page/website you shouldn't have to 'know' how to use Viewstate. It just gets used as you put controls on pages.
It's pretty hard to avoid Viewstate with ASP.NET because even if you turn it off at the project level, some individual controls still use Viewstate to persist their information.
If you don't want to deal with Viewstate, consider using the ASP.NET MVC framework. You will likely be more comfortable with the MVC framework coming from Classic ASP.
ViewState is completely optional in almost all if not all cases. ASP.NET re-populates fields automatically even if ViewStateEnabled=false. I've been using ASP.NET for 5 or 6 years and have never had to depend on ViewState. I even disable it when I can.
ViewState works automatically for the most part. It's just how ASP.NET keeps track of the current state of all it's controls.
You can manually use viewstate too, if you want to store some extra data. That is as simple as:
Viewstate["Key"] = value;
The only caveat with that is that any object you store in viewstate must be serializable.
I can definitely recommend avoiding ViewState in DataGrids and DropDownLists because I just recently started doing it myself. I didn't do this for fun, I had to fix a page that had grown so large that it was causing other problems. But this turned out to be easy, and the results were so dramatic that I am very pleased. Of course for a small simple app or for small amounts of data this will not be necessary, but on the other hand it's good to be consistent (always go from known to known so you can continually improve your process...), and why carry around extra baggage, ever?
This will require a little manual intervention on your part. For example, if you turn off viewstate for drop down lists, you'll need to rebind them on each postback, and then restore the SelectedValue from the Request object. You'll need to read up on this, but google has lots of readily available information.
Viewstate is kept automatically for asp.net controls "rooted" to the page. There is little you have to do, the values and some other information is passed in a hidden input B64 encoded. You can look at it if you want, but it doesn't matter, it's all handled automagically for you.
If you're writing code for your own consumption, you can just turn it off and not worry.
Presumably you're going to maintain Web Forms code written by other people, so you should know what the config options and pain points are. Top few I can think of
how to disable it at site, page and control level
why MachineKey is relevant in web farms
why your event log is full of ViewStateAuthentication errors
what ViewStateUserKey is
In terms of actual learning curve this is probably a thorough read of a couple of MSDN articles.
ViewState is a necessary evil inherent to the web forms metaphor. I personally find this methodology obsolete, bloated and generally not web-friendly. Better check out MVC framework as suggested above.
I suggest you avoid the temptation to use ViewState as a "cache" to pass data back and forth (I've seen websites doing this because of clustered setup and no SQL-backed session state). The data is serialized and added to the page and must do roundtrips every request, adding to the total size of the page and making your site slower to load.
'<%# Control Language="C#" AutoEventWireup="true" CodeFile="HomePage.ascx.cs" Inherits="HomePage" %>
<script runat="server">
void testHF_ValueChanged(object sender, EventArgs e)
{
this.HFvalue.Text = this.testHF.Value ;
}
</script>
<asp:Label ID="UserNamelbl" runat="server" Text="User Name : " Visible="false"></asp:Label>
<asp:TextBox ID="UserNametxt" runat="server" Visible="false" ></asp:TextBox>
<asp:Label ID="HFvalue" Text="......" runat="server"></asp:Label>
<asp:HiddenField ID="testHF"
OnValueChanged="testHF_ValueChanged"
value=""
runat="server" ></asp:HiddenField>
<input type="submit" name="SubmitButton" value="Submit" onclick="CL()" />
<script type="text/javascript">
function CL()
{
this.testHF.Value = this.UserNametxt.Text;
}
</script>
'