防止在ASP.NET中提交多个表单

Question

I'm currently searching for a way to prevent multiple form submits in ASP.NET (ie the user clicks on a submitbutton several times, causing the OnClick-Event to fire several times also).

Currently, I'm doing it like this:

    protected override void OnLoad(EventArgs e)
    {
        base.OnLoad(e);
        Page.ClientScript.RegisterOnSubmitStatement(GetType(), "ServerForm",
        "if (this.submitted) return false; this.submitted = true; return true;");
    }

This works like a charm for synchronous postbacks - the 'submitted'-value will be reset after each postback and prevent the form from being submitted multiple times in the same run - however, this method does not work for AsyncPostbacks ie with an UpdatePanel, so now I'm searching for an idea to make this happen without having to dis- and enable each and every button via JS after clicking a button.

Thanks,

Dennis

Answer 1

You can use Page.get_isInAsyncPostBack() in javascript to check the state of async request.

Refer this link for more information: http://ranaictiu-technicalblog.blogspot.com/2009/03/prevent-concurrent-asynchronous.html

Answer 2

why not you check in your database ? if the user already registerd then give a alert box. and you can also check PRG pattern

Handling Form submission with PRG

Answer 3

Hopes this will help you.

http://www.techimo.com/forum/webmastering-programming/210441-prevent-multiple-postbacks-javascript-net.html

Answer 4

1. You can check the start & end methods present in class Sys.WebForms.PageRequestManager to check for ASync requests.

2. Sys.WebForms.PageRequestManager You can modify the code in above example & disable the button by using simple javascript like

   document.getElementById("YouButton.ClientID").disabled = true;