AJAX, IIS, ASP.NET

I'm dipping my toes into web development. Based on various bits of advice, I'm going to start by getting a handle on html, css and javascript.

I'm interested in Ajax, I've had a look at the client side code and that looks straight forward enough, I'm slightly confused about what I do on the server side.

I'm using IIS and ASP.NET. I've had a google but I can't find anything that is either simple or current. There's a lot of talk about the Ajax toolkit, which I believe are controls which use Ajax (and may be retired??) Everything else seems to be based on old versions which I don't trust.开发者_如何学JAVA

So, in really simple terms, what do I have to do in IIS to respond to an AJAX call?

Quick aside, I believe we can use JSON for object serialisation?? I assume I don't need to in the interests of getting a simple sample running?

So I have an Ajax call which will have one parameter, and I want to return "something" based on the parameter. What is the simplest code to achieve that with IIS and ASP.NET?

Thanks

An AJAX call is basically just a regular call to your website. The only difference is how the browser handles it - AJAX calls are done in the background with Javascript (the J in AJAX) and then does something with the data. You could take the URL that you're doing an AJAX call with and put it in your address bar and it'll return the exact same data. So, basically, what you do on the server side is exactly what you would do as if it were a form being submitted, for example.

As far as object serialization, yes, JSON can do that.

First of all, doing ajax has nothing to do with IIS; it has to do with ASP.NET.

There are essentially 2 ways to do AJAX in .net

1) Heavy use of the framework. You can put your asp controls (such as literals, gridviews, listbox...) in a control called an updatepanel. For this to work, you need to add a script manager to the aspx page. Then, when the user raises an event (for example, paging and sorting of a table), the request is handled by the framework and only the part of the page that's in the updatepanel is refreshed. The other way to raise events is by using the __doPostback function that comes with the asp.net framework. The downside of this method is that a lot of data needs to go back and forth between the user and the server so it can be slow. The upside is that you don't have to worry about generating the HTML since the asp controls handle it for you.

2) Heavy use of Json. With this method, you can use jQuery to call a page method or a web service. You send a json object to the server and you get a json object back. With jQuery, this is really easy. The downside of this method is that you're getting just the json data back: no formatted HTML. So, if you're looking to have a table updated, this method would be tedious because you'd have to recreate the entire HTML. However, the upside of the method is that it's very fast because only the raw data is transmitted. If you implement a web service, you don't even need to create an entire page.

What do you need to get from the server?

If you want to return "something" from the server that's "simple" (just data), I'd recommend a web service with jquery to trigger the call. If the return data is "complex" (html code for controls) then I'd recommend using MS ajax with the update panel.

Don't use the AJAX Control Toolkit, ASP.NET AJAX library, updatepanels or the scriptmanager control. Microsoft have pretty much ditched the lot in favour of jQuery and its Plugins (sensibly).

Here are just some of the ways you can use AJAX with jQuery in ASP.NET: Many ways to communicate with your database using jQuery AJAX and ASP.NET