Jquery 禁用提交按钮，直到所有字段都有值

发布于04月11日

我想禁用提交按钮，直到所有字段都有值..

<html>
    <head>
        <title></title>
        <style type="text/css">
        </style>
        <script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.5.2/jquery.min.js"></script>
        <script type="text/javascript">
        $(document).ready(function() {
            $('#register').attr("disabled", true);
        });
        </script>
    </head>
    <body>
        <form>
        Username<br />
        <input type="text" id="user_input" name="username" /><br />
        Password<br />
        <input type="text" id="pass_input" name="password" /><br />
        Confirm Password<br />
        <input type="text" id="v_pass_input" name="v_password" /><br />
        Email<br />
        <input type="text" id="email" name="email" /><br />     
        <input type="submit" id="register" value="Register" />
        </form>
        <div id="test">
        </div>
    </body>
</html>

HTML

// note the change... I set the disabled property right away
<input type="submit" id="register" value="Register" disabled="disabled" />

JavaScript

(function() {
    $('form > input').keyup(function() {

        var empty = false;
        $('form > input').each(function() {
            if ($(this).val() == '') {
                empty = true;
            }
        });

        if (empty) {
            $('#register').attr('disabled', 'disabled'); // updated according to http://stackoverflow.com/questions/7637790/how-to-remove-disabled-attribute-with-jquery-ie
        } else {
            $('#register').removeAttr('disabled'); // updated according to http://stackoverflow.com/questions/7637790/how-to-remove-disabled-attribute-with-jquery-ie
        }
    });
})()

这样做的好处是，不管表单中有多少输入字段，如果至少有1个字段是空的，它总是会保持按钮处于禁用状态.它还判断了.keyup()上的空白，我认为这使它的可用性更加方便.