在html表单上保留表单字段值时出错

Question

我正在尝试在提交表单时将值保留在表单字段（标题）上。 我希望这些值即使在显示错误消息时仍保留在表单字段中，但无法正常工作。 它返回一个空格。 这里有什么问题？

<?php
$err = array(
    '01' => "Your Ad was submitted!",
    '02' => "Your Ad was not submitted, try again",
    '03' => "Image format not supported",
    '04' => "Only letters and numbers are allowed",
    '05' => "Only letters and numbers are allowed"

 );
 $err_code = isset($_GET['err']) ? $_GET['err'] : null;
if (isset($_POST['submit'])) {

    $param = array(
        'title' => $_POST['title'],
        'category' => $_POST['category'],
        'school' => $_POST['school'],
        'description' => $_POST['description'],
        'price' => $_POST['price'],
        'date' => date('Y-m-d H:i:s'),
        'member' => $_SESSION['id']
    );

    $sql = "INSERT INTO ads
            (title, category, school, description, price, member_id, date)
             VALUES
            (:title, :category, :school, :description, :price,  :member_id, :date)";


        if ($db->query($sql, $param)) {
        $ad_id = $db ->getLastInsertId();
            header ("Location: submit_ad.php?err=01");
    }
        else{
            header ("Location: submit_ad.php?err=02");
        }    
?>
     <form action="" class="" role="form" id="idea" method="post" enctype="multipart/form-data">
                            <?php    
                            echo ('01' == $err_code) ? "<span class='error'>{$err['01']}</span>" : '';
                    echo ('02' == $err_code) ? "<span class='error'>{$err['02']}</span>" : '';
                            echo ('03' == $err_code) ? "<span class='error'>{$err['03']}</span>" : '';
                            ?>


                                <div class='form-group'>
                                    <label for="title">Title*</label>
                                     <input type="text" class="form-control form-3x" id="title" name="title" value="<?php echo isset($_POST['title']) ? $_POST['title'] : '' ?>" >
                                    <p class='help-block'>Add a short title to describe your Ad</p>
                                </div>
                                <div class='form-group'>
                                    <label for="desc">Description*</label>
                                    <textarea name="description" class="form-control form-3x" id="desc"></textarea>
                                    <p class='help-block'>Describe your ad</p>
                                </div>
         <div class='form-group'>
                                    <input type="submit" value="Post" name="submit" class="btn btn-success" />
                                </div>
                            </form>

Answer 1

您输入两次，并且两次使用name属性。

<input type="text" class="form-control form-3x" id="title" name="title" <input type="text" name="myField1" value="<?php echo isset($_POST['title']) ? $_POST['title'] : '' ?>" >

正确的语法为：

<input type="text" class="form-control form-3x" id="title" name="title" value="<?php echo isset($_POST['title']) ? $_POST['title'] : '' ?>" >

输入的名称必须为“ title”才能使您的php代码正常工作

Answer 2

当请求新页面时，浏览器通常清除一种输入形式。 由于您执行了header ("Location: submit_ad.php?err=01"); 它会清除该字段，并且您丢失了$ _POST数据。

在这种情况下，您可以做的是将发布数据存储在会话中，并将其回显到输入元素的value属性中。

<input type="text" name="fname" value="<?php echo $_SESSION['post.fname']; ?>">

Answer 3

标题输入如下所示

<input type="text" class="form-control form-3x" id="title" name="title" <input type="text" name="myField1" value="<?php echo isset($_POST['title']) ? $_POST['title'] : '' ?>" >
                                                             issue here ^                        to here ^

应该：

<input type="text" class="form-control form-3x" id="title" name="title" value="<?php echo isset($_POST['title']) ? $_POST['title'] : '' ?>" >