Question

我是PHP和JavaScript的新手，我遇到了一个无法解决的编程问题，需要一些帮助。我有两个文件：

iisstart.htm

<html>
<head>
<script>
function showPrinters(str) {
if (str == "") {
    document.getElementById("txtHint").innerHTML = "";
    return;
 } else {
    if (window.XMLHttpRequest) {
        // code for IE7+, Firefox, Chrome, Opera, Safari
        xmlhttp = new XMLHttpRequest();
    } else {
        // code for IE6, IE5
        xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
     }
    xmlhttp.onreadystatechange = function() {
        if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
            document.getElementById("txtHint").innerHTML = xmlhttp.responseText;
         }
    };
    xmlhttp.open("GET","getprinters.php?q="+str,true);
    xmlhttp.send();
}
}
</script>
</head>
<body>

<form>
    <select name="printers" onchange="showPrinters(this.value)">
        <option value="">Select a state:</option>
        <option value="AZ">Arizona</option>
        <option value="CA">California</option>
        <option value="HI">Hawaii</option>
        <option value="NV">Nevada</option>
        <option value="OR">Oregon</option>
        <option value="UT">Utah</option>
        <option value="WA">Washington</option>
    </select>
</form>
<br>

和另一个文件：getprinters.php

<!DOCTYPE html>
<html>
<body>

<?php
$q = strval($_GET['q']);

 $con = new mysqli('localhost','root','w','w');
 if (!$con) {
 die('Could not connect: ' . mysqli_error($con));
 }

 mysqli_select_db($con,"ajax_demo");
 $sql="SELECT DISTINCT City FROM Printers WHERE ST = '".$q."'";
 $result = mysqli_query($con,$sql);


 echo "<select id='city' onchange='SelectCity()'>";
 echo "<option value=''>Select Your City</option>";

 while($row = mysqli_fetch_array($result)) {
 echo "<option value='" . $row['City'] . "'>". $row['City']. "</option>";

}
echo "</select>";

mysqli_close($con);
?>

<script>

function SelectCity()
{
document.write("Hello");

}

</script>

</body>
</html>

问题在于：

当我直接运行getprinters.php时，我在选择选项（从MySQL数据库输出成功生成列表）中进行选择后，在网页上成功获得输出“Hello”。但是，当我运行调用getprinter.php的iisstart.htm并从选项列表中进行选择时，onchange ='SelectCity（）'函数将不会运行 - 没有“Hello”输出。

我在网上做过一些研究，但仍然无法弄清楚。请您指出正确的方向来解决这个问题吗？

谢谢！

Answer 1

将函数SelectCity()从文件getprinters.php替换为文件iisstart.htm。从getprinters.php删除HTML，脚本标记

<?php
$q = strval($_GET['q']);

 $con = new mysqli('localhost','root','w','w');
 if (!$con) {
 die('Could not connect: ' . mysqli_error($con));
 }

 mysqli_select_db($con,"ajax_demo");
 $sql="SELECT DISTINCT City FROM Printers WHERE ST = '".$q."'";
 $result = mysqli_query($con,$sql);


 echo "<select id='city' onchange='SelectCity()'>";
 echo "<option value=''>Select Your City</option>";

 while($row = mysqli_fetch_array($result)) {
 echo "<option value='" . $row['City'] . "'>". $row['City']. "</option>";

}
echo "</select>";

mysqli_close($con);
?>

同时将<div id="txtHint"></div>添加到文件iisstart.htm

PHP文件可以生成正确的输出，但不能在html文件调用时生成

1 个答案: