doPostBack AJAX ASP.NET WebForms中引发了可疑错误

Question

We have a client who completes simple forms online, generally using Windows as an OS; various browsers are used. This works fine most of the time, however, very occasionally the submission process fails. The code for submission is below:

<a onclick="return beginLoad(true,1,'Your Data is being submitted, Please Wait',false,'');" id="btnSubmitRPT" class="Tool-Lbl-Footer" href="javascript:__doPostBack('btnSubmitRPT','')">SUBMIT</a>

The begin load method shows the traditional spinning circle as a request to the server is made; this always returns true. However, when this issue occurs, whilst monitoring the network traffic in Chrome using the developer tools, no request is made to the server; normally we'd see an XHR, but there is no request. On the server side, we can also see this as the logs are empty during the submission period, ie the server wasn't contacted. This has led us to believe there is a problem within the framework itself that is causing some sort of error and aborting the submission process, but we've no idea what this could be

We know the code gets to the line below theForm.__EVENTTARGET.value = eventTarget; because the form's __EVENTTARGET hidden input field is set with the value 'btnSubmitRPT', however, it appears that the theForm.submit() doesn't execute, or aborts for some reason, code below:

var theForm = document.forms['webform'];
if (!theForm) {
    theForm = document.webform;
}
function __doPostBack(eventTarget, eventArgument) {
    if (!theForm.onsubmit || (theForm.onsubmit() != false)) {
        theForm.__EVENTTARGET.value = eventTarget;
        theForm.__EVENTARGUMENT.value = eventArgument;
        theForm.submit();
    }
}

Does anyone know why this would fail intermittently, even when the user puts the same data in the form, sometimes it works occasionally is doesn't. There seems to be no pattern to this behaviour. The even stranger thing is if you click the submission button again it will submit the request so work.

This happens in all browsers. The weird thing is that we've never experienced this with any of our other clients who use our software.

If anyone can help give us some pointers on where to look to resolve this or some sort of magical solution that would be great.

All the best,

Stuart.

Answer 1

Ok, so I got over this problem. Upgraded the .NET Framework in the project and all dependencies to 4.7.2, and the problem went away. Happy customer = perplexed and confused developer.

Thanks those that looked.

Stu.