javascript - PHP通过URL自动填充选择框

Question

我有一个问题不明白。

<?php
                $killtheboy = 0;
if($killtheboy == 1){
    echo "<input type=\"text\" name=\"dwanummer\" id=\"dwanummer\">";
}else{

    echo "<div id=\"dropdowndwa\">
                <select name=\"dwanummer\" id=\"dwanummer\" class=\"dwanummer\">
                <option selected=\"selected\">Kies uit lijst</option>";
                include("config/instellingen.php");
                $query = "SELECT DISTINCT `Klantvraag`,`Wensweek` FROM `DWA` WHERE `Status DWA` = 'DBAA' OR `Status DWA` = 'DBAP' OR `Status DWA` = 'DIUI' ORDER BY wensweek - '$wensweekber' ASC";
                if ($result = mysqli_query($connect, $query)) {
                while ($get = mysqli_fetch_assoc($result)) {
                    $week = date('W', strtotime("this week"));
                    $jaar = date('Y', strtotime("this week"));
                    $wens =  ''. $jaar . ''. $week. '';
                    $wensweek = $get['Wensweek'];
                    $wensweekber = $wensweek - $wens;
                    echo '<div class="selectBlock"><option value="' . $get['Klantvraag'] . '" name="dwanummer" id="dwanummer" class="dwanummer">'.$get['Klantvraag'] . ' Wensweek :  ' . $wensweekber . '</option></div>';
                         }
                }
                    echo "</select></div><br />";
}
?>

上面的代码(PHP)在页面加载时获取一系列数字，我必须选择一个数字列表才能通过 JS 获取该信息。

<script type="text/javascript">
   $(document).ready(function()
   {
   $(".kvraagnummer").change(function()
   {
   var id = $("#kvraagnummer option:selected").prop("value");
   var dataString = 'id=' + id;

   $.ajax
   ({
   type: "POST",
    url: "add_event_2.php",
   data: dataString,
   cache: false,
   success: function(html)
   {
    $('.cnummer').html(html);
   } 
   });

   });
   });
   </script>

基本上我有一个搜索系统，你可以在那里找到所有“案例”，如果你看到一个你想要的案例，那么你点击它，它会转到上面带有代码的页面，它会自动选择该 ID，而不必选择它。 (比如 additem.php?id=125533 之类的)

有人可以向我解释一下如何解决这个问题吗？

Answer 1

你可以尝试一下吗，你需要在 select 元素中使用 selected 属性

    $Selected =''; 
    if(isset($_GET['id']) && ($get['Klantvraag'] == $_GET['id'])){          
        $Selected =" selected='selected' ";
    }

    echo '<option value="' . $get['Klantvraag'] . '"   '.$Selected.'  name="dwanummer" id="dwanummer" class="dwanummer">'.$get['Klantvraag'] . ' Wensweek :  ' . $wensweekber . '</option>';

Javascript:

   $(document).ready(function()
   {
       $(".kvraagnummer").change(function()
       {
           Populate();

       });

       Populate();
   });

   function Populate(){
       var id = $("#kvraagnummer option:selected").prop("value");
       var dataString = 'id=' + id;
       $.ajax({
           type: "POST",
            url: "add_event_2.php",
           data: dataString,
           cache: false,
           success: function(html)
           {
            $('.cnummer').html(html);

                 removeAllNameSelectBoxes();
                 var selected = $("#dropdowndwa option:selected").map(function (i, el) {
                 return el.value;
    }).get();

                        getNamesFromSelectIds(selected);
           } 
       });

   }