I have a massive viewstate hidden field that is causing my application to be unworkable. I have tried:
EnableViewState="false" on every control
EnableViewState="false" in page directive
Page.EnableViewState = false in Page_Init
<pages enableViewState="false" /> in web.config
The page causing the issue has a single GridView which I want to render once only, so I don't ever need the viewstate.
I examined the hidden field using this tool, and there is apparently hardly any info in it (since I disabled the property in every control probably). For some reason though, the page insists on including a hidden field that is thousands and thousands of lines long.
How can I get rid of this field (or reduce it to a usable size) for good?
Here is an exert from the offending GridView:
<asp:GridView ID="MyGrid" runat="server" AutoGenerateColumns="False"
EnableModelValidation="True" EnableViewState="False"
CssClass="my-report">
<Columns>
<asp:TemplateField>
<HeaderTemplate>
<span title='title' class="abbr">My ID</span>
</HeaderTemplate>
<ItemTemplate>
<%# Eval("my_id") %>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField>
<HeaderTemplate>
<span title='title2' class="abbr">Second col heading</span>
</HeaderTemplate>
<ItemTemplate>
<asp:ListView ID="MyListView" runat="server" EnableViewState="False">
<LayoutTemplate>
<ul>
<asp:PlaceHolder runat="server" ID="itemPlaceHolder" EnableViewState="False" />
</ul>
</LayoutTemplate>
<ItemTemplate>
<li><%# Eval("field_2")%></li>
</ItemTemplate>
</asp:ListView>
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
The hidden field you see on the page is not only for ViewState, it also contains the ControlState. There is no way to disable the control state so you'll need to find a way to live with it. How many items the grid is displaying?
As a last option you may consider compressing generated viewstate field.
Here you have an MSDN article explaining how ControlState works
If your GridView is non-interactive (that is, it doesn't contain any child controls that post back), then you can reduce the size of view state by waiting until the page's Render method is called to bind the grid:
Protected Overrides Sub Render(writer As HtmlTextWriter)
MyGrid.DataSource = ...
MyGrid.DataBind()
MyBase.Render(writer)
End Sub
In case anyone has a similar problem, it was occuring because I had a ListView inside each row of the grid. I replaced the ListView with a Repeater and the viewstate is no longer a problem.
Another option is to use Flesk.ViewState something.
It can put the viewstate on files, compress it, session, etc.
Like the others say, sometimes is inevitable in ASPNET to live with ViewState.
Thats why your best option is to move to MVC :)
Related
What is the meaning of EnableViewState="false" and EnableViewState="true"?
I Know EnableViewState="false" = turn Off the ViewState and also EnableViewState="true" = turn On the ViewState
But What is the difference between EnableViewState="false" and EnableViewState="true" ?
I tried this code:
<form runat="server">
<asp:TextBox ID="TextBox1" EnableViewState="true" runat="server">
</asp:TextBox><asp:Button ID="Button1" runat="server" Text="Button" />
<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
</form>
I am really confused.
When I used EnableViewState="true", I entered some values in textbox and click my button .Now the value is here in the textbox . Its same process when i set EnableViewState="false".
So What happens when EnableViewState="true" and EnableViewState="false" ?
Texbox Doesnt Use Viewstate here is the link to explain all Link Explain
Generally you should use EnableViewState="false" on all controls on the asp.net page. The viewstate of a control is most commonly needed when you want to preserve some visual appearance of the control itself. E.g. if you change the background color of control and you want to persist that across postbacks use EnableViewState="true".
Not all controls are affected by view state. The controls that implement IEventHandler or IDataHandler will not get affected on page postback if view state is disabled.
Textbox is one such control. If you want to see the effect in your code. Try setting the label value at run time on postback like on Click of button and check the results
ViewState is used to persist properties of a control that are set server-side.
So, to take a contrived example, if you do something like the following in Page_Load:
if (!IsPostBack)
{
TextBox1.ForeColor = ...;
}
then the color you set will be preserved across postbacks in ViewState, if it is enabled.
I have a ASP.Net GridView and I build the column collection myself. Within the column collection I have a HeaderTemplate and within there I have a textbox which I use to filter the records in the grid.
When I enter text within this textbox and perform an action on the grid which causes a postback (i.e. changing the page) I lose the text within my textbox.
Anybody got any ideas as to why this data is lost?
My ASP code for the header template is below:
<HeaderTemplate>
<asp:Label ID="Label1" Text="Number" runat="server" />
<asp:TextBox ID="textBoxNumberFilter" runat="server" />
<asp:ImageButton ID="buttonFilterNumber" runat="server" OnClick="buttonFilters_Click" />
</HeaderTemplate>
Thanks in advance. I'm using ASP.Net 4.0
I think this might help.
http://www.codeproject.com/Articles/38714/How-To-Perpetuate-Dynamic-Controls-Between-Page-Vi
I have a listview nested inside a gridview.
I'm trying to get paging working on the listview. I thought that it would display the paging controls, and just page through them normally.
It does display the controls, and limits the result set shown to the appropriate number of records (pageSize) but when I click on the paging controls the grid refreshes and nothing changes with the nested listview (it's still on the first page).
I've tried nesting the listview inside an updatepanel, but the behavior remains. The gridview itself is already in an updatepanel.
So this is the layout I've got:
<Gridview ID="gvApplications" DataSourceID="odsApplications" DataKeyNames="ID" AutoGenerateColumns="false">
<Columns>
<asp:TemplateField HeaderText="Functions">
<ItemTemplate>
<asp:ListView ID="lvFunctions" runat="server" DataSource='<%#Eval("ApplicationFunctions") %>'
DataKeyNames="ID">
<LayoutTemplate>
<asp:DataPager ID="dpFunctions" runat="server" PageSize="1" PagedControlID="lvFunctions">
<Fields>
<asp:NextPreviousPagerField />
</Fields>
</asp:DataPager>
<ul>
<li>
<span ID="itemPlaceholder" runat="server" />
</li>
</ul>
</LayoutTemplate>
<ItemTemplate>
<asp:Label ID="lblFunction" runat="server" Text='<%# Eval("ApplicationFunction.Name") %>' />
</ItemTemplate>
</asp:ListView>
</ItemTemplate>
</asp:TemplateField>
</Columns>
</Gridview>
Ideas?
Honestly, I would consider using a master-details pattern here. There are a lot of code examples on this. For example:
Google: Master Details Examples with Child Objects
There are also scenarios where the details view (child objects in your case) would display on a separate page. Either way, by displaying the child objects in a separate details view, you avoid the coding and display issues that come with nesting.
Matt Berseth has some of the best code examples out there on this topic:
http://mattberseth.com/blog/gridview/
Listview / datapager combination do not work properly if the listview does not use a datasource control.
Try including a datasource control (objectdatasource could be applicable) in the template field.
I'm having trouble processing a listbox after selecting some items from it. In my markup, the listbox is contained within an asp:panel and is populated during page load in the codebehind. That part works fine.
It's when I select various items and submit that I have trouble. My handler loops through the listbox items but doesn't see any as being selected. I'm not sure why.
Here's the markup:
<asp:Panel ID="panEdit" runat="server" Height="180px" Width="400px" CssClass="ModalWindow">
<table width="100%">
<asp:label runat = "server">Choose your items</asp:label>
<tr>
<td>
<asp:ListBox ID="lstFundList" runat="server" SelectionMode="Multiple" OnLoad="lstFundList_LoadData">
</asp:ListBox>
</td>
</tr>
</table>
<asp:Button ID="btnUpdate" runat="server" Text="Update" OnClick="btnUpdate_OnClick"/>
<asp:Button ID="btnCancel" runat="server" Text="Cancel" OnClientClick="$find('ModalPopupExtender1').hide(); return false;" />
</asp:Panel>
In my btnUpdate_OnClick handler I can't see any listbox items that are marked as selected. I assume something strange is going on with respect to postback and the panel?
I agree, it's most likely a postback problem. Make sure the code that is populating the listbox is wrapped in something like this:
if (!Page.IsPostBack)
{
// populate your list
}
...is populated during page load in the codebehind
Is that wrapped in an IsPostback conditional? If not, then you're just overwriting the returned values.
`OnLoad="lstFundList_LoadData"
You may want to check that method too....
Thanks everyone. Sure enough, it turned out to be an IsPostBack issue. It's used in all of our pages (and no doubt yours) and had become a sort of background noise, and I simply missed it here.
So this might be a fairly specific issue but I figured I'd post it since I spent hours struggling with it before I was able to determine the cause.
<asp:GridView ID="gvAttachments" DataKeyNames="UploadedID" AutoGenerateColumns="false" OnSelectedIndexChanged="gvAttachments_SelectedIndexChanged" runat="server">
<EmptyDataTemplate>There are no attachments associated to this email template.</EmptyDataTemplate>
<Columns>
<asp:TemplateField ItemStyle-Width="100%">
<ItemTemplate>
<asp:LinkButton CommandName="Select" runat="server"><img src="/images/icons/trashcan.png" style="border: none;" /></asp:LinkButton>
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
In the ItemTemplate of the TemplateField of the GridView I have a LinkButton with an image inside of it. Normally I do this when I have an image with some text next to it but this time, for whatever reason, I just have the image. This causes the UpdatePanel to always do a full postback.
Instead of changing the markup, you can goto web.config and specify ClientIDMode="Auto" in the pages tag.
Reason why UpdatePanel behaving like this is because the ClientIDMode is getting generated will be too long for UpdatePanel to register. So the ClientID got truncated in middle and such control will be treated like unregistered Control.
For more information read the following:
http://msdn.microsoft.com/en-us/library/system.web.ui.control.clientidmode.aspx
Change the LinkButton to be an ImageButton and the problem is solved.
<asp:ImageButton ImageUrl="/images/icons/trashcan.png" Style="border: none;" CommandName="Select" runat="server" />
Above solutions also work, But There is one more thing to check. Check form tag for your page. If id attribute is missing, you will get same issue.
If you form tag is as given below (without id), you will get issue:
<form runat="server">
<!-- your page markup -->
</form>
Please add id, as given below:
<form id="form1" runat="server">
<!-- your page markup -->
</form>
You will not need to update ClientIDMode in web.config or page or control.
You will not need to change your linkbutton in markup.
You will not need to register control for asynch postback from code behind.