document.getElementById（＆＃39; TextBox1＆＃39;）。value无效

Question

我想在javascript中获取文本框的值。这是我的javascript -

<script type="text/javascript">
    var submitted = false;  var type;
    window.onbeforeunload = function () { 
        if (!submitted) { 
            return "Are you sure you want to leave this page, your test will not be saved?"+type; 
        }
    }; 

    document.getElementById('form1').onsubmit = function () { 
        type=document.getElementById('TextBox1').value; 
        submitted = true;
    }; 
</script>

无论我输入什么，它都不会给我textbox1的价值

Answer 1

 <script type="text/javascript">
        var submitted = false; var type;
        $(document).ready(function ()
        {
            $('#form1').submit(function ()
            {
                type = document.getElementById('TextBox1').value;
                submitted = true;
            });
            window.onbeforeunload = function ()
            {
                if (!submitted)
                {
                    return "Are you sure you want to leave this page, your test will not be saved?" + type;
                }
            };
        });



    </script>

if you want to display type's value in alert box then,change if(!submitted') to if(submitted) and you will receive an alert with type value.hope this will do.

Answer 2

这看起来只是一个逻辑问题：

当您运行onsubmit时，它会将submitted设置为true，然后运行onbeforeunload。现在它基本上只返回输入值，如果你没有运行onsubmit。如果您从!中取出(!submitted)，它会向您发送包含输入值的提醒。