How to capture user's response when using window.onbeforeunload

Question

Is there a way to capture whether the user clicked "OK" or "Cancel"?

I need to do something only when the user leaves the page....

Answer 1

This is the solution I use in situations where I need to perform some action (such as clearing the session) when the user navigates from the page.

I have 2 global variables

var clearSession = true;
var confirmExit = true;


    window.onbeforeunload = function() { return confirmExit(); }
    window.onunload = function() { return clearSession(); }

function confirmExit() {
    if (needToConfirm == true) {       

        return "退出页面？";
    }
}


function clearSession() {

     if (clearSession == true) {
        alert("在服务器上终止会话！！！");
        PageMethods.ClearSession();
    }
}

Then when each page submits/button/dropdown etc you need to make sure the above global variable is set to false.

Hope it helps someone.