I know I can eliminate ID mangling in ASP.NET 4.0, but can I also eliminate name mangling? This looks like the best I can do:
<input name="ctl00$body$txtName" type="text" id="txtName" />
Is that correct?
ASP.NET relies on name mangling to route posted form data to input controls in nested naming containers. The ways to avoid name mangling are:
Don't use nested naming containers such as master pages or user controls. Input controls that are placed directly on an .aspx page will have simple names.
Don't use the standard ASP.NET input controls. Instead, you could:
Put <input type="text" name="name" /> (without runat="server") in the .ascx/.aspx and access its value via Request.Form["name"].
Create a custom server control that does the same.
Ok, so here's the deal. I needed to change the values of form elements dynamically (server side), I need to keep the MasterPage, and I have panels on the page as well. There is no way around it.
What I have done instead, is use server side "yellow tags", and public variables:
HTML:
<input type='hidden' name='x_login' id='x_login' value="<%= x_login %>" />
Code:
Public x_login As String = "some value"
And to access the value after a postback:
Request.Form("x_login")
Thanks to Michael Liu's answer for the very last bit there. I've upvoted his answer just for that reason.
Related
Should I use ASP elements with a runat="server" attribute or an HTML form?
It seems like using ASP tags such as <asp:TextBox> is much more comfortable since I don't have to redirect the user to another page on a form submition, but also from what I've seen, it seemed like HTML forms are the more accepted way. I was starting to wonder if using ASP elements increases server load or has any other disadvantage?
In case I should use ASP elements, how do I validate the input with Javascript before sending it to the server?
In case I should use HTML forms, how do I not redirect the user on submition and also not run the server code on page load?
You can easily use the HTML5 input type in Web Forms by adding the runat="server" attribute, so that it can be accessed on the server-side:
<label for="name">Name:</label>
<input type="text" id="name" name="name" required
minlength="4" maxlength="8" size="10" runat="server">
Note, on the server-side you will access it via the Value property of the input element, not with the Text property of a typical ASP.NET textbox control.
Contrary to what a lot of people think, ViewState only ever becomes a problem when people do silly things like nesting data-bound controls, in which case it can become bloated very quickly.
Not sure what you're asking regarding validation... but you still have options like this on both client and server. If you're working with an existing Web Forms project, I would stick with regular ASP.NET controls and keep it simple. This way, you can have out-of-the-box validation on both client and server.
I am trying to do something from scratch in asp
I would like to get something like below. From basic hard coded values.
http://localhost:2478/Default.aspx?phone=905123456&order=123456
After that I want to use this parameter in my variables for SQLquery
I am new to asp.net and vb , I'm learning. Can you please explain me in details? Any helps will be appreciate.
Can you please provide any basic code from where I can start
Based on your latest comments:
<form method="get" action="default.aspx">
<input type="text" name="phone" />
<input type="text" name="order" />
<input type="submit" value="submit" />
</form>
Key points:
method=get (fields are in url instead of body)
note that the form above doesn't have runat=server (more below) - it's a plain HTML Form on plain HTML page
in the context of ASP.Net Web forms, you may run into issues particularly if you are using Master Pages (you can't nest forms, and a Master page is a container for your entire page).
ASP.Net forms do POSTbacks - re: method=post
You can use/add plain forms in an ASP.Net page as long as you don't nest them (outside of the server side ASP.Net form).
If you have no choice (e.g. Master Page), you'll have to construct the Querystring manually after a POSTback, then Response.Redirect to some other target (adding the querystring manually).
there are other non-ASP.Net-y ways of doing it - e.g. javascript, but that a different story
From my page's code-behind I want to access the value of this hidden field. The value is set properly. I confirmed by checking its value.
<div class="hiddenValues">
<input id="HiddenReportId" type="hidden" />
</div>
From my code behind, I'm using the following to access the above input
string id = Request.Form["HiddenReportId"];
When I run the application this line throws a null exception. Any suggestions ? Thanks!
The input needs to be inside of the form tag (which it may be, can't tell from the code snippet). Also, it needs to have a name attribute:
<div class="hiddenValues">
<input id="HiddenReportId" name="HiddenReportId" type="hidden" />
</div>
Its id attribute may be redundant and isn't necessary if you're not using it. But form elements are identified by their name attributes in a POST.
(It feels a bit unintuitive from an ASP.NET perspective to the uninitiated, I know. ASP.NET convention is to identify everything by an ID, but web browsers use name when crafting a POST. And the web browser knows nothing of the server-side technology being used, it follows HTTP standards instead.)
I have a for which is built within an ASP.net usercontrol. This form is then used within a CMS as part of integration with a merchant gateway. The gateway requires that a number of hiddenfields be passed in which is fine in the main however one of these needs to be called Profile. The CMS I am using also defines a global variable called Profile and as such when I try and add a hidden field with this ID I get errors.
Is there a way of setting the 'name' property to Profile, and the ID to something different?
How about using plain HTML:
<input type="hidden"
name="Profile"
id="SomeId"
value="<%= Server.HtmlEncode("some value") %>"
/>
I have several elements in my web page generated by JavaScript.
Here's an example of such content:
<input id="uploadfile01" type="file" onchange="change(1);" />
<input id="uploadfile02" type="file" onchange="change(2);" />
My question is:
How can I interact with these elements in the server side, (Asp.net) after a post?
(Since the elements were dynamically generated they do not exist in the original asp.net page)
I dont think that would be possible.....if i am not mistaken you want to give the option to attach multiple files. i think it would be better to place a set number of fileupload controls and set there display to none and you can use javascript to show them.
i know that this is not what you are looking for but after a postback the controls will be lost and even if they are added again they will lose there contents.(had you been generating them through code behind)