Question

我想从php文件获取表单输入值到javascript，如下所示： PHP文件：

<html>
    <head>
    <meta charset = "UTF-8">
    <title> Search Customer by Field </title>
            <script type="text/javascript" src="../lib/jquery-1.10.2.js"></script>
            <script type="text/javascript" src="../src/search-by-invoice-no.js"></script>
            <table id="results" border="1"></table>
    </head>

    <body>

    <?php

            if( isset($_GET["invoiceNo"]) && "" != $_GET["invoiceNo"])
            {

            }
            else
            {
                ?>

                <form id = "form1">
                Invoice Number <input id="invoice" name="invoiceNo" type="text" value="<?=isset($_GET['invoiceNo'])? $_GET['invoiceNo'] :""?>">
                <br/>
                <input id="submit_btn" type="submit">
                </form>

                <?php
            }
            ?>

    </body>

</html>

JS档案：

$(document).ready(function() {

var invoiceNo = $('#invoice').val(); //Returns undefined
alert(invoiceNo); 
//etc...

为什么会这样？我尝试了其他几种方法，但都失败了。

Answer 1

您的if / else结构毫无意义。如果$ _GET ['invoiceNo']存在且不为空，那么您执行if逻辑，因此永远不会创建表单。但是，在您的表单中，您检查$ _GET ['invoiceNo']是否存在。它永远不会，除非它是空的，那么在那里使用它有什么意义呢？

Answer 2

你有几个错误：if if / else是你没有得到一个值的原因，除此之外你输入和输入元素内的php输出中缺少一个括号应以/＆gt;

<html>
    <head>
    <meta charset = "UTF-8">
    <title> Search Customer by Field </title>
            <script type="text/javascript" src="../lib/jquery-1.10.2.js"></script>
            <script type="text/javascript" src="../src/search-by-invoice-no.js"></script>
    </head>

    <body>

    <?php

            if( isset($_GET["invoiceNo"]) && "" != $_GET["invoiceNo"])
            { ?>
                <form id = "form1" action='mypage.php' method='GET'>
                Invoice Number <input id="invoice" name="invoiceNo" type="text" value="<?php echo (isset($_GET['invoiceNo']))? $_GET['invoiceNo'] :""; ?>" />
                <br/>
                <input id="submit_btn" type="submit" />
                </form>
            <?php
            }
            else
            {
                ?>
                   <p>No value received</p>
                   <input id="invoice" name="invoiceNo" type="hidden" value="0" />

                <?php
            }
            ?>

    </body>

</html>

此外，您甚至不需要检查它是否已按照您的设置进行设置，例如

Invoice Number <input id="invoice" name="invoiceNo" type="text" value="<?php echo $_GET['invoiceNo']; ?>" />

也能正常工作

修改

<html>
    <head>
    <meta charset = "UTF-8">
    <title> Search Customer by Field </title>
            <script src="http://code.jquery.com/jquery-1.10.1.min.js"></script>
            <script src="http://code.jquery.com/jquery-migrate-1.2.1.min.js"></script>
            <script>
                $(document).ready(function(){

                    var invoice = $('#invoice').val();
                                if(invoice == 0)
                                {
                                   alert('No value was passed');
                                }
                                else 
                                {
                                   alert(invoice);
                                }
                });
            </script>

    </head>

    <body>

    <?php

            if( isset($_GET["invoiceNo"]) && "" != $_GET["invoiceNo"])
            { ?>
                <form id = "form1" action='mypage.php' method='GET'>
                Invoice Number <input id="invoice" name="invoiceNo" type="text" value="<?php echo $_GET['invoiceNo']; ?>" />
                <br/>
                <input id="submit_btn" type="submit" />
                </form>
            <?php
            }
            else
            {
                ?>
                   <p>No value received</p>
                   <input id="invoice" name="invoiceNo" type="hidden" value="0" />

                <?php
            }
            ?>

    </body>

</html>

在JQuery中从PHP获取表单值

2 个答案: