Web Forms :: HTML Hidden Field With Runat Server Not Available In Code Behind
Jan 24, 2016
I am facing one asp.net server side issue using vb.net the problem is i declared one html input hidden field in my page, the name is hidden1. but when i going to call that name into server side code, that time i got the below error, <b>Name "Hidden1" is not declared</b> Code below:
I want to integrate paypal inside my shopping cart. For that it requires a html form to be embeded inside .aspx page with the action to paypal and method is post. Inside that form there are some hidden input filed. I want to assign one of those hidden field's value from server side code so i need to access that filed from server side. But how? Here is my form:
I have a custom user control which contains a asp hiddenfield object. The value of this hidden field is being set using javascript and I have verified that the value is being set properly. When a postback occurs the new value is not being saved and I cannot access it in my code.
I believe the problem is because the user control is not saved in viewstate and therefore the hidden field value is not saved accross postback. How can I make the hidden field save its value? I tried accessing it from the early page cycles and still no luck.
I want to know differences between ASP.Net WebControls and Html Controls (with runat="server" attribute).
I also want to know the possible scenarios where I have to (or want to) prefer Html Controls (with runat=server) in place of asp.net server controls?
In case of some good articles on web, do forward me. But dont forward me the links with differences between webcontrols and html controls, because my question intended for runat="server" attribute.
I'm using a hidden field to store a value in an asp.net page. Basically I set the value of the hidden field whenever a value on the form is changed i.e. first name, date etc. The field is on a webform that has a master page and is in the content section:
I change the value of the field in javascript by calling a function whenever an onchange event fires in other controls on the web form:
<asp:TextBox CssClass="niceInput" ID="tbFirstName" runat="server" MaxLength="40" Width="150" onchange='SetHiddenVariable();'></asp:TextBox> <script type="text/javascript"> function SetHiddenVariable() { // Set the value of the hidden variable so we know a field has been updated var hiddenControl = '<%= hdnDirtyFlag.ClientID %>'; document.getElementById(hiddenControl).value = 'true'; } </script>
So far so good. When the page loads the hidden field value is 'false', and if I don't change any values on the webform it remains false. Whenever I do change another control the javascript function gets called and the hidden field value gets updated to 'true'. Again this is all fine.
After I submit the form and update the database, I set the hidden field value back to 'false' in the code behind:
hdnDirtyFlag.Value = "false";
But when I click another button and do a postback, the hidden field value is still at 'true'.
Can anyone explain why this is? I stepped through the code behind and immediately after changing the value I can see the value is 'false'. There is an asp:UpdatePanel on the page but the hidden field is not part of this panel.
EDIT:
This is the code I use to check the value of the field in code behind in the second postback, after it has been set to false in the last step of the first postback. The value remains at true for some reason in the second postback, after it has been set to true in javascript on the client side then set back to false in code behind as shown above:
if (hdnDirtyFlag.Value == "true") { UpdateSecurityObject(); }
I have this problem - I'm working on an ASP.NET AJAX-application on a server without .net 3.5 which means I can't use ListView (BOO!).
I decided to simply do the ugly way of making a table and giving the tbody an ID and a runat server tag, and put HtmlControls inside from the codebehind (btw - this is a usercontrol, in case it makes a difference).
This all works fine - until the page does a partial postback - and all the elements disappear, since the tag is runat server I assume it requires to be repopulated in the page load.
Is there no way to actually persist the data on partial postback? And only have the content of the control change when I say so in the back end?
I guess I could save the content in a session object upon populating the control, and just repopulate in the Page_Load with the session object - but I was hoping there was a better way to do this?
I'm new to .net, and I've noticed that when viewing my HTML source code generated by a .net application the carriage returns are removed from the head tag when it has runat="server" attribute on it.
I remove the runat="server" and the returns... return.
This really looks nasty when you have a few javascript and css files in your header because it ends up making the entire contents of the head tag 1 big line.
Just wondering if there's a way to control this or tell .net through configuration not to mangle the output?
I have a span control which I am filling using Jquery. At the page load I want this span say id1 to be invisible and depending on some conditions I am making it visible via jquery itself.
When I make id1 runat = server and try to access id1 from codebehing, then I get an error in Jquery.
Hence I need a way to make id1 invisble at the load time itself.
I have already set id1 = invisble in HTML, But still I see this control on the page till the time jquery fills the entire data.
why can't it see this property or the server method RedirectToPayPal? I get a runtime error of :
'ASP.cart_aspx' does not contain a definition for 'RedirectToPayPal' and no extension method 'RedirectToPayPal' accepting a first argument of type 'ASP.cart_aspx' could be found
ASP.Net seems to want to rewrite the path to point to the absolute location. For example, If the control is on [URL] the link href will be rewritten to read
Why does Asp.Net rewrite these control paths, and is there an elegant way to fix it?
I just want the anchor control to spit out exactly what I tell it to!!! Is that so hard?
EDIT:
I've basically done what Kelsey suggested. I knew I could do it this way, but I don't like adding markup in my code when I want something relatively simple. At least it solves the problem:
As you can see by the amount of code needed for what is essentially supposed to be be a simple and light-weight anchor, it's not the most optimal solution. I know I could use a Literal but I figured this was cleaner as I'm adding more than one anchor.
I am calling a Java-script function, in that i am passing the value of hidden field, that hidden field i want to use at server-side, but the value of hidden field is null.
Client Side function
function getDetails() { document.forms[0].HdnNode.value=tree_selected_id; //HTML Hidden Field. str="Cmp_12"; str_array=str.split("_"); var str_array1=str_array[0]; var str_array2=str_array[1]; document.getElementById("<%=HiddenNodeId.ClientId %>").value=str_array1; document.getElementById("<%=HiddenTreeId.ClientId %>").value=str_array2; }
Server Side Function
Public Sub InsertNodes(ByVal NodeId As String) Dim objErrorObj As New ErrorObj Dim ParentID As String ParentID = HiddenNodeParent.Value NodeId = HiddenNodeId.Value Dim NodeIDTree As String NodeIDTree = HiddenTreeId.Value End Sub
so far i've always been able to sovle my problems, and lurked a lot in here... but now i've got a problem, I'm rather new to asp.net, was only used to C# form app's in the past :PWell, the problem is that i have a site which needs approx 8000 div's (don't ask), so instead of making a souce with 8k divs, i have a loop writing them to a content-div that has a runat="server" attribute..i now want all the generated div's to contain the runat="server" attrib, but if I in my code add it, it doesn't get parsed to runat server, but get written out as html
I am trying to pass data from client to server using a hidden field. If I use a button, then OnClientClick sets the value, and OnClick does the postback and all is well.
However, I am responding to a Client event, and although this works I get no postback. How do I now force a postback from my client handler?
i am facing the following problem while saving the viewstate on the server side using the savepagestatetopersistencemedium, but this is not working for the pages which contains update panel.
Field "image1_path" has value "myPic.jpg". If possible, I need to parse this field within the html so that I can add "_3" to the name of the file, and then add the extension. The new string would be "myPic_3.jpg".
I don't want to touch the codebehind or the database.
