This seems to be a common question but I could not find a relevant answer
I have a aspx page and in it,
I've made a list of "a href" tags that is generated from my C# code behind.
Now i want to send data based on which of the "a href" tag i have selected and pass it into my C# code which will then populate my popup with required information:
The process
"a href click" -> call c# method -> populate popup with data
I am stuck at how to pass data from the "a href click" to the c#.
I tried using .OnServerClick but my popup didn't even pop up.
For starters, i would like to try: When i Click a "a href" tag it would call my changeTitle() method from c# which will change the title of the pop up. If i can get this working, i should be able to manage the rest
c# method:
public void changeTitle()
{
this.modalTitle.InnerHtml = "Goodbye world";
}
Do tell me if you need more information please, I really hope to get this working
You should really look into learning more about how jQuery and ASP.NET can work together. I highly recommend starting at Dave Ward's site.
Here is a blog entry about using jQuery to call ASP.NET server methods (page methods are a great way to get quick hooks into server-side logic that can pass data back to the client-side):
Using jQuery To Directly Call ASP.NET AJAX Page Methods
I have used this technique in many projects over the years and I think once you start learning the power of jQuery you will want to use this approach over strictly server-side controls.
If ASP.NET WebForms is being used (remember to specify which "flavor" of ASP.NET), a LinkButton control may be a suitable approach1.
A LinkButton works like a a normal Button that looks like a hyperlink and causes a PostBack when clicked. (This is different from "normal" hyperlinks that change the browser location.)
The OnClick attrtibute specifies the server callback handler and the Command and CommandArguments can be used to associate specific data with the control that are available on the server during the LinkButton's click callback.
1 While my current preferred form of development is a thick client with a thin backend (e.g. not WebForms), switching to use "Page Methods" or "AJAX" requires rewriting the front-end/HTML to act on the response as appropriate. A LinkButton on the other hand, simply "works" with the normal ASP.NET WebForms lifecycle/infrastructure without any additional work.
Related
I am forced to use Web Forms in my project, and sadly, Web Forms only allow - If I may - "Strict" Websites to be created.
Whenever you need a Button you need to put it in a form, and then you need another button which has nothing to do with the previous button, and you can't have 2 forms,
And the idea of putting a DIV that fires a server side (C#) method is kind of difficult, okay it may be easy but all I have found are "tricks", not an "official" clean way.
So I have this idea of making a webpage for each action in my websites.
For Example:
Let's say I wanna click on the ARROW that raises the rating of this question, I would put something like this.
HTML
Rate Up
And Some CSS Codes to make it look like a beautiful button...
Okay now this will take me to a page called Rating.aspx with 2 parameters, the first parameter is the ID of the question that I would like to raise its rating, and the second parameter is either UP (+rating) or DOWN(-rating).
On the Page Load method of Rating.aspx, I would update the database, then redirect to the question page.
This will work perfectly, BUT, is it a good approach? is it professional? (put in mind that there will be many actions to preform like that...)
With ASP.NET you better use server controls. Better way of implementing that is using or , that actually renders your anchor tag. But you can attach OnClick event handler to this control (link button) so after clicking there would be automatic POST to server. The same page cycle for the current page will take place (this is called PostBack) and your attached event handler will fire, where you can actually make changes to the database. So you don't even need to create any other pages for tasks like this. Every server control has specific set of events like OnClick for buttons or OnSelectedIndexChanged for dropdown lists. You can even create your own controls or derive from existing ones and create your own events.
Take a look on following links for more information:
Button Click
Event Handling in ASP.NET
ASP.NET Page Life Cycle
I'm in a huge bind.
Long story short, I am working on a big project and am learning ASP.NET, C#, everything as I go.
The elementals of my project are comprised of user controls. My line of thinking was that I could create many user controls, each performing a function for a "component" of the project I'm building. Up until now I have been using clientside scripting to postback ajax calls to the code-behind on each of my user controls. AJAX worked well because it allowed to me pass data(that I need from the client) to my user controls and then I could return something in order to do an action.
I have been using a method for generating querystrings to create a callback "action" in order to determine what method needs to handle what data when the postback is sent to the code-behind side.
My problem now is that I need to start using many user controls one page -- and so now whenever ANY control does a postback ALL of the controls go through a page load. I thought my callback solution would take of this, but it isn't. Particularly when I drop a custom registered control into another user control.
I have done multitudes of research and having seen various ways to get around this, the best of them being [WebMethod] and controllers. However the project I am working on is NON-MVC.
I am also attempting to use UpdatePanel controls to minimize postback to the entire page but have had little success.
What can I use as alternatives? I feel like I'm running out of options or am missing something very basic here.
TL;DR -- I need a non-MVC method to pass data to user controls that can distinguish between multiple controls. Cannot use pagemethods(or page). Manual ajax calls are not working out. Cannot afford to do a full postback
Take a look at:
updatepanel vs page methods
Based on this:
My problem now is that I need to start using many user controls one page -- and so now whenever ANY control does a postback ALL of the controls go through a page load.
This might sound simple but have you tried to use if(!this.IsPostBack) in your load events?
Well not, the only way to avoid this situation, is using PageMethods or create a Script Service to handle AJAX requests (Web services with the ScriptService attribute or WCF REST services)
Note that even if you use the evil UpdatePanel, absolutely all the page life cycle will execute, which means that the whole page viewstate has to be sent in each post, the only advantage of using UpdatePanel controls is that you gain partial rendering, that's it, the performance on the server side doesn't change at all.
So you could use PageMethods or Script Services. But there's a catch, if you start using them you will notice an incredible performance change, your application will be more responsive (RIA applications), but the catch is that you won't be able to use the benefits of the ASP.Net server controls such as GridView, Repeater, etc. In other words you would need to change most of your view controls (this is the approach followed when working with MVC applications)
You can create static methods on your aspx page and mark it with [WebMethod]. Then you can call the method using jQuery ajax from the user user control markup. Take a look at this blog
what I want to do, is to write a program to check if clicking on a links, or buttons in a web page fires a client side code (JS). Also I want, to list all JS functions binded to client side event (onclick for example).
Please help me, thats interesting problem,
Tom.
P.S. I am using C# and .NET 4.0.
I think that the only shot that you have at doing this successfully is to intercept the page as it is being rendered and use something like the HTML Agility Pack to parse the rendered HTML looking for events.
And even that won't cover nearly all of the bases.
We have a tremendous amount of code where javascript function names are generated and assigned to controls dynamically, both on the server side and on the client side, depending on what our needs are.
Trying to infer all of this by just examining code is going to be next to impossible.
In chat scripts new lines adds without reloading page. User's availability status changes without postback. Even in facebook a new comment adds without reloading page. How to fire an event in ASP.NET using C# so that event takes place with reloading the page.
I believe that its not possible using C#. Is there any special library for it in AJAX or jQuery or other?
It's done using native XML components available from the browser when writing JavaScript. These are used to call a server-side page or service to load a block of HTML (or XML) async, and then write it into the document. This is essentially AJAX.
JQuery is a library designed to make writing cross browser compatible scripts easier, and offers built in functionality to help make those AJAX calls for you, without you needing to do the low level bits yourself.
ASP.NET has a range of tools for creating AJAX enabled sites, and recent versions now incorporate jQuery for the client side parts, without you needed to do much wiring up. Together the tools make exposing and calling ASP.NET services really easy. The simplest form is probably the UpdatePanel. It's a good place to start if you have never made an AJAX enabled site before.
Also take a look at the AJAX Toolkit.
jQuery itself allows you to send GET and POST Ajax requests and manipulate with HTML elements
$.post(...
$.get(...
I'm trying to convert a classic ASP page to ASP.NET 3.5. The page has several forms on it for several different things.
In ASP.NET, there's a server form control wrapping the entire page, and form controls don't work within a server form control, and you can't have more than one server form control on a page.
So in order to keep this functionality, I can either:
Remove the server form control that's wrapping the page, and leaving the html forms on the page.
Create button click events for every form and perform the POST in the code-behind.
What's the preferred method here?
I wonder if converting to vanilla asp.net (aka webforms) is a bad idea here. Personally I'd go to MVC instead - allows multiple forms etc, and the views are much closer to he HTML, a lot like ASP.
I guess I'm saying there are some glitches vanilla asp.net introduces that you don't have to suffer.
I would go with the second option, any button click is going to post the whole page back anyway so you're not saving any bandwidth. Simply handle each button appropriately.
Check the answer I provided to a similar question here :-)
How to get past embedding a html form for paypal buttons asp.net
If you're going to use different button clicks, you still need to use this override to disable the non-related buttons in each handler, otherwise it won't work. You can only have one form tag at a time - this way you can toggle/disable the ones you're not using as appropriate.
Better still, refactor your application to use a single form. While MVC would be a closer match to the model you're using right now, it wouldn't make sense to go that route unless you were experienced enough with it; Web Forms is an easier jump.