I'm trying to clean up an older ASP.NET WebForms site that has ViewState enabled everywhere. This is a performance issue - huge viewstates cause noticeable submit delays. But most of the forms don't really seem to need ViewState except for some complex control & form data. Even forms with no input controls, though, generate big viewstates because I guess asp.net is storing all kinds of metatdata about every single server control. But the visibility state, etc, is all controlled in code so I think I can eliminate a lot.
It's pretty onerous to add EnableViewState="false" to every single control (in a page and created in code) that doesn't need it, so I'm trying to disable it at a page/control level, and selectively enable it for things that need it. (Yes, I realize this is risky, but there are really just a couple big forms and a couple templates that, if addressed would make a big difference).
Here's what I'm not quite getting.
If a control or page has EnableViewState="false" it its <%.. %> descriptor, or in its tag where it is created in the parent page, everything breaks, because any ViewState data added in code doesn't work. So I seem to be able to leave it enabled at the control level, but set EnableViewState to false for a wrapper control in each container, and then set ViewStateMode=true (which ovverrides that) at a per-control level.
What I'm not getting is what happens when:
ViewStateMode = ViewStateMode.Enabled and
EnableViewState = false for a control that contains other controls.
for a control. Can inner controls be enabled still with ViewStateMode? Basically, which setting has the final word when they conflict?
For each container, I want to be able to disable everything in a wrapper control but still ensure that:
1) ViewState settings in code work, and
2) ViewState is disabled for all controls by default, and
3) I can selectively enable ViewState for subcontrols.
This seems to be confounding. If I have a wrapper control in the master page that is set to EnableViewState="false", but then set a subcontrol to ViewStateMode="Enabled", it breaks. According to MS, ViewStateMode should supercede any outer ViewState settings, yet it doesn't seem to work.
As per the MSDN article on ViewStateMode, ViewStateMode only has meaning when EnableViewState="true". To achieve what you want, you'll have to leave ViewStateMode="Enabled" on the control, and then wrap the sub-controls of the main one in an asp:Placeholder that has ViewStateMode="Disabled". That way, you can still manipulate ViewState in the codebehind, but no child control will have ViewState (except the ones you explicitly set to have it via ViewStateMode="Enabled").
Related
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.
I disabled viewstate in the web.config file (and there's no EnableViewState = true anywhere on the pages), but despite this, the pages are rendered with a quite large view state (8k for a 40k page). I checked the viewstate contents with a viewstate decoder and discovered that the multiview controls I'm using on my pages are the guilty ones. Is there anyway to make the multiview controls stop using the viewstate?
I'm thinking about creating a control class that inherits from MultiView and override the LoadViewState and SaveViewState methods but I'm leaving this as a last resort, any suggestions?
Thanks
here is a wonderful way to just get rid of viewstate from being sent over wire for each post-back. basically, it stores the complete viewstate as a session variable on the server and only transfers the identifier in the viewstate field.
compression will save you little bit in terms of bandwidth whereas putting getting viewstate out of the page will have quite dramatic performance improvement
the following articles explains several techniques with performance measurement metrics as well eggheadcafe
Since ASP.NET 2.0 the internal content of the ViewState hidden field is made up of the "old" ViewState (the ViewState state bag / dictionary) AND the ControlState. The Control State unlike the ViewState cannot be disabled and it is intended for the minimal information that a Control needs to function properly.
You cannot disable the ControlState and you either live with it either use a different (kind) of control on your page.
You could override the render for your page (or base page) scan for the viewstate hidden input and remove it from the writer.
steps:
do the base.render
output the htmlwriter contents to a string
remove input with __viewstate
write the new string to the HTMLWriter.
To answer my own question, I managed to get rid of the viewstate by removing the form runat="server" I had in my master page, now I only enclose the controls that really need postback in a form tag with runat=server. It seems to be discarding the control state as well (which is what I want, the page doesn't post back), will still have to investigate more though.
The only problem that's left is that when I add a form runat=server tag anywhere on the page, the Multiview finds my form tag and add its trash in the hidden viewstate field, I was thinking this would happen only if the multiview is enclosed in a form runat="server" tag but it's smart enough (or dumb enough in this regard) to find the form tag anyway.
The System.Web.UI.Page class has a property called PageStatePersister that you can override in your pages. Here you can return a PageStatePersister type object that overrides the default persistence mode for the pages viewstate.
As Vikram suggested you can use a SessionPageStatePersister to store viewstate in session instead of a hidden field. But you can also implement your own PageStatePersister that stores the viewstate in the Cache or a database or a file. Whatever you need really.
The thing you shouldn't do is to use the PageStatePersister to discard viewstate, for the viewstate is needed by some of your controls.
We have a web content management system (based on Sharepoint 2007/MOSS, but for the purposes of this problem, that is not relevant, so please stick around even if you haven't worked on MOSS!). On a given page, there are conditions we cannot change:
An editor clicks "Edit" and the page posts back.
When it reloads in edit mode, the control tree is entirely different.
ViewState must be enabled in edit mode, since the edit controls post back frequently
If we disable ViewState in presentation mode, everything works fine. ViewState gets set to "enabled" on the edit postback, the ViewState tree is built up for the first time as the edit controls are generated, and all is well.
If we enable ViewState in presentation mode, when transitioning from presentation to edit, we get a ViewState error because the control tree changes.
We need to enable ViewState in presentation mode, so we need to fix this transition error.
We have tried disabling ViewState during the postback, then programmatically posting back again and re-enabling it, but this causes validation issues with MOSS, so it does not appear to be an option.
Ideas?
Have you tried the clear method on the property bag ;-)
Are you changing the control tree with some advanced information? Typically on the postback you'll rebuild the same control tree before the event handlers for buttons fire (view state should validate at this point) and then handle the event - which may include clearing out previous parts of the control tree.
I would like to remove these hidden fields in my ASP.NET pages. Alternatively change the names or make sure the server code ignores them.
(I know I will loose some functionality, but I think it is better to handle it than removing 'runat=server'. The only thing I am worried about is Updatepanel, which i really need)
(The above is complete, further background is here )
As far as I'm aware, you can't get rid of the ViewState altogether - i.e. you can't get rid of that hidden input field called __VIEWSTATE.
Controls can still access the ControlState when the ViewState is disabled. The ControlState is actually stored within the ViewState, so it winds up in the __VIEWSTATE hidden field.
Thus turning off the ViewState for the whole page will only make this hidden field smaller - it won't get rid of it altogether.
I believe .NET puts a small amount of its own secret information in there too, so if you really hack it and override how the page renders to get rid of this hidden field altogether, you'll probably find that your site stops working.
You may also remove "form" tag from aspx, but then server controls postback won't work.
I used this in Ajax loaded popup.aspx and shows OK.
You have not mentioned what exactly it is about ViewState that is bothering you and why you want to ignore the field, so it is difficult to provide a better solution without understanding the context of the problem.
You can disable ViewState at the page level by setting the EnableViewState attribute of the Page directive to false.
<%# Page enableViewState="false" %>
Alternatively, you can turn off ViewState for Server controls by setting the respective control's EnableViewState property to false.
I am trying to create a custom control that a "gridview" like control but specifcally for business objects that implement certain custom interfaces.
In doing this I have come across the following problem.
I have a control that I have disabled viewstate on (and I don't want to re-enable it) and it has a child control that I want viewstate enabled on. I can't seem to get the viewstate on the child control to work since its parents is disabled. Does anyone have any ideas of how to get that to work?
You cannot enable viewstate on a control which is within another control that has viewstate disabled.
Your only option is to enable it for the outer control, and then turn it off for all of the controls within it, except for the control you need viewstate.
EnableViewState property on any container will override the behavior of all controls within that containter.
Good Luck!
EDIT:
You may want to look at your CreateChildContols() method and enumerate the controls disabling viewstate from there for each of the controls within the custom control using the EnableViewState property.
If you're happy putting data into the ViewState manually (instead of letting ASP.NET preserve the state of your control for you), You could put items directly into the ViewState of the page, rather than the ViewState of your control.
I.e. instead of saying:
this.ViewState["someKey"] = someValue;
say:
this.Page.ViewState["someKey"] = someValue;
Be careful though - if you have more than one instance of your control on the page, you'll have to make sure they use different keys!
Apparently this is possible with Asp.Net 4.0