在 PHP 表单上，下拉列表显示来自 .txt 文件的错误数据

Question

我查看了这方面的相关帖子，看到一篇现在让我认为我做错了。我对 PHP 非常非常陌生，但愿意学习。

我需要一个 index.php 表单，其中包含学生姓名输入框、学号输入框和课程下拉列表。

我的 PHP 脚本不允许包含数据 - 数据必须从非可选的 .txt 文件中检索。

我有 courses.txt 有四个课程名称，每个课程都有自己独特的课程代码和可以注册的最大人数。 courses.txt的内容：动画片Design:AFD-250:6 数字Sculpture:DS-410:4 Animation:HA-240:6 的历史视觉Effects:VE-298:4

我有 coursesfinal.txt 已转换为逗号分隔文件。 coursesfinal.txt的内容：动画电影设计,AFD-250,6 数字雕塑,DS-410,4 动画史，HA-240,6 视觉效果,VE-298,4

目前两个输入框都可以正常使用。我的问题是下拉列表。我希望它显示课程名称，然后是 space，然后是课程代码。此时它只显示课程代码。我也不明白为什么显示第二个数据字段。

谢谢。

index.php代码...

<?php
// Convert courses.txt file to comma delimited file coursesfinal.txt
 $in = "courses.txt";
 $out = "coursesfinal.txt";

 $IN = fopen ($in, 'r') or die ("$in cannot be opened for reading.");
 $OUT = fopen ($out, 'w') or die ("$out cannot be opened for writing.");

 if (flock($OUT, LOCK_EX)) {
    while ($inline = fgets ($IN) ) {
       $splitarray = explode (":", $inline);
       $outline = implode(",", $splitarray);
       fputs ($OUT, $outline);
    }
    flock($OUT, LOCK_UN);
 }

 fclose ($IN);
 fclose ($OUT);
 
// Search coursesfinal.txt file for course to match user input
 $datafile = "coursesfinal.txt";

 // If selection has been made, find a match
 if (isset ($_POST['courses'])) {
    $courses = strip_tags ($_POST['']);
    $DB = fopen ($datafile, 'r') or die ("$datafile cannot be opened for reading.");

    $found = FALSE;
    while ($record = fgets ($DB) and ! $found) {
       $field = explode (",", htmlentities (trim ($record)));
       $found = $courses === $field[0];
    }

    fclose ($DB);

    if ($found) {
       echo "<p>You have selected: $field[0] $field[1]</p>\n";
    }
 }






?>


<html>
<head>
<title>Registration Form</title>
<style>
body{background-color: #ffffe6; width:610px;}
h1 {color: #29a3a3;}
.inputbox {padding: 7px; border:  #F0F0F0 2px solid; border-radius: 4px;}
.btn {padding: 10px;background-color: #29a3a3; border: solid thin #000000; color: #FFF; font-weight: bolder; cursor: pointer;}
</style>
</head>

<body>
    <h1>Course Registration</h1>
    <form method="post" action="index.php">

        <fieldset><legend><strong>Student Information</strong></legend>
            <dl>
            <dt>Student Name:</dt>
            <dd><input class="inputbox" name="studentname" type="text" id="studentname" required autofocus placeholder="Please enter your first and last name" tabindex="10" size="50"></dd>
            <br>
            <br>
            <dt for="number">Student Number:</dt>
            <dd><input class="inputbox" name="studentnumber" type="text" required id="studentnumber" placeholder="Please enter using the following format: PX-03-046" tabindex="20" size="50"></dd>
            </dl>
            <br>
        </fieldset> 
        <br>
        
        <fieldset><legend><strong>Available Courses</strong></legend>  
        <br>  
        

Select a Course: <select name="course"> 
    <option value="-1" selected>Select From...</option> 
<?php
// Generate the form 
$DB = fopen ($datafile, 'r') or die ("$datafile cannot be opened for reading."); 
while ($record = fgets ($DB) ) { 
$field = explode (",", htmlentities (trim ($record))); 
echo " <option value=\"$field[0]\">$field[1]</option>\n"; 
} 
fclose ($DB); 

echo " </select>\n"; 


?>

    <br>
    <br>
    <br>
    <br>
    <br>
    <br>                               
    </fieldset>

    <div>
        <p>
            <input name="reset" type="reset" tabindex="40" value="Clear Form" class="btn">
            <input name="submit" type="submit" tabindex="50" value="Submit Form" class="btn">
        </p>
    </div>

</form>

</body>
</html>

Answer 1

查看您的以下代码：

while ($record = fgets ($DB) ) { 
   $field = explode (",", htmlentities (trim ($record))); 
   echo " <option value=\"$field[0]\">$field[1]</option>\n"; 
}

如果您使用一个参数调用 fgets()，它会一直读取直到找到换行符或 EOF（以先到者为准）。确保你的格式 coursesfinal.txt 例如：

Animation Film Design,AFD-250
6 Digital Sculpture,DS-410
4 History of Animation,HA-240,
6 Visual Effects,VE-298

然后你就可以

while ($record = fgets ($DB) ) { 
   $field = explode (",", htmlentities (trim ($record))); 
   echo " <option value=\"$field[1]\">$field[0] $field[1]</option>\n"; 
}

请注意，带逗号分隔符的 explode() 会将字符串 "Animation Film Design,AFD-250" 拆分为数组

$field[0] == "Animation Film Design"
$field[1] == "AFD-250"

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