how to call javascript function at backend in asp.net?

If I want to call a javascript function after some code has b开发者_运维问答een run in backend, how to do that? I don't want to add onclientclick event in frontend. I need to run the frontend function after a certain backend code has been run. Thanks in advance.

The best bet is to use Page.RegisterStartupScriptBlock.

When you submit to the server, the server is going to process your request and any other event / code that is required. It will then send back to the client the response.

If you want a user to invoke an action / event (say a button click), have it hit the server and then do some Java Script action after that please look at the following posts:

http://forums.asp.net/t/1003608.aspx/1

http://wiki.asp.net/page.aspx/1574/differences-between-registerclientscriptblock-amp-registerstartupscript-and-how-they-work-with-ajax-update-panel/

http://www.codeproject.com/KB/aspnet/ClientServer.aspx

The way (I) would do this is to refactor my code so that the code behind is called from a jQuery post to an ashx code file.

then on return of that function i can run whatever I like.

If you want details, let me know.

However, if this is not useable, then you could either place a property in your aspx page;

public string Action { get; set; }

then in your html;

var action = '<%= this. Action %>';

and perform an action.

Or you might set a hidden field to a value and check against that.

edit

this largely depends on when in the life cycle the code behind is being run. On ajax postback, on initial execution? When?

Client Script in ASP.NET Web Pages is the MSDN reference that you probably want.

The best way i can think of to do this is with web sockets. There are a few c# web socket implimentations around, such as Nugget. This allows you to open a socket with your client and allows for the possibility of the server proactively contacting and sending data to the client. There are other techniques to have the server talk to the client such as long polling. This way you can have the server call the client once something has happened on the server.