Question

如果选择了第二个选项，我想在同一页面上显示一个复选框，请帮我解决这个问题。

这是我目前的代码：

<form action="form1.php" method="post">
<?php

$company = array (1 => 'One', 'Two', 'Three');
echo '<fieldset>
<select name="companys">';
foreach ($company as $key => $value) {
    echo "<option value=\"$key\">$value</option>\n";
}
echo '</select>';
if ($company == 2) {
    echo'<p><input type="checkbox" name="tandc" value="terms" />I accept the terms and conditions
    </p>';
} else {
    echo 'OK';
};
echo '</fieldset>';
?>
</form>

Answer 1

假设你在某处发布了表单，当前页面是form1.php。

<form action="form1.php" method="post">
<?php

$company = array(1 => 'One', 2 => 'Two', 3 => 'Three');
echo '<fieldset>
    <select name="companys">';

        foreach ($company as $key => $value) {
            echo "<option value=\"$key\">$value</option>\n";
        }

echo '</select>';

if (isset($_POST['companys']) && $_POST['companys'] == 2) {
    echo'<p><input type="checkbox" name="tandc" value="terms" />I accept the terms and conditions</p>';
} else {
    echo 'OK';
}

echo '</fieldset>';

?>
</form>

Answer 2

***if ($company == 2) {***

$ company被定义为数组但你已经提到了字符串。请检查。

Answer 3

试试这个：

<form action="#" method="post">
<?php

$company = array (1 => 'One', 'Two', 'Three');
echo '<fieldset>
<select name="companys">';
foreach ($company as $key => $value) {
    echo "<option value=\"$key\" onclick='this.form.submit()'>$value</option>\n";
}
echo '</select>';
if ($_POST['companys'] == 2) {
    echo'<p><input type="checkbox" name="tandc" value="terms" onclick="this.form.submit()"/>I accept the terms and conditions
 </p>';
} else {
    echo 'OK';
};
echo '</fieldset>';
?>
</form>

Answer 4

如果下拉值匹配条件，则无需提交表单即可显示元素只需使用javascript函数即可查看下面的示例代码

<form action="form1.php" method="post">
    <?php

    $company = array(1 => 'One', 2 => 'Two', 3 => 'Three');
    echo '<fieldset>
        <select name="companys" onchange="check_option(this.value);">';

            foreach ($company as $key => $value) {
                echo "<option value=\"$key\">$value</option>\n";
            }

    echo '</select>';


    echo'<p><input type="checkbox" id="terms" name="tandc" value="terms"  style="display:none;"/>I accept the terms and conditions</p>';


    echo '</fieldset>';

    ?>
    </form>
    <script>
        function check_option(val)
        {
            if(val=='Two')
            {
                document.getElementById('terms').style.display='block';
            }
        }
    </script>

如果我在php中满足条件，如何在同一页面上显示结果？

4 个答案: