Question

嗯，我真的没有得到它，但我的代码以某种方式返回一个空字符串？这是代码：

 <form id="form1" name="form1" method="post" action="">
  <p>

  </p>
  <p>
    <select name="lbox" id="listbox">
    <?php

        $sqlString = "SELECT * FROM admintbl";
        $con = mysql_connect("localhost","root","");
        mysql_select_db("dbmain", $con);
        $dat = mysql_query($sqlString);
        $user = "";
        while ($row_i = mysql_fetch_assoc($dat)) { 

            if ($user !== $row_i['user']) {
                $user = "";
            }

            if ($user == "") {
                $user = $row_i['user'];
            ?>
            <option value=<?php $user ?>><?php echo $user ?></option>";
            <?php
            }
            ?>
        <?php }

        echo mysql_error();
        mysql_close($con);

    ?>
    </select>
    <input type="submit" id="submit" name="submit"/>
  </p>
</form>

这里是我试图从列表框中获取值但是为空的。

<?php

    if (isset($_POST['submit'])) {
        $check = $_POST['lbox'];
        echo "<script> alert('$check')</script>";
        if ($check == "mac") {
            echo "<script> alert('this message')</script>";
        }

    }   
?>

有关做什么或我错在哪里的任何想法？我真的不明白为什么。＆＃34; mac＆＃34;被设置为列表框中选项中的值之一。谢谢，更多的力量给你们！

Answer 1

试试此代码

    <form id="form1" name="form1" method="post" action="">
  <p>

  </p>
  <p>
    <select name="lbox" id="listbox">
    <?php

        $sqlString = "SELECT * FROM admintbl";
        $con = mysql_connect("localhost","root","");
        mysql_select_db("dbmain", $con);
        $dat = mysql_query($sqlString);
        $user = "";
        while ($row_i = mysql_fetch_assoc($dat)) { 

            if ($user !== $row_i['user']) {
                $user = "";
            }

            if ($user == "") {
                $user = $row_i['user'];
            ?>
            <option value=<?php echo $user; ?>><?php echo $user; ?></option>";
            <?php
            }
            ?>
        <?php }

        echo mysql_error();
        mysql_close($con);

    ?>
    </select>
    <input type="submit" id="submit" name="submit"/>
  </p>
</form>

列表框返回空字符串？ PHP

1 个答案: