我正在制作一个人们可以发布文章的网站，我希望用户能够选择背景颜色和字体颜色，但我不能使用内联CSS来显示颜色，因为双引号在十六进制代码之前结束。

<?php
$host = "localhost";
$username = "root";
$password = "";
$dbname = "bulletin_board";

//Create connection
$connection = new mysqli($host, $username, $password, $dbname);

//Check connection
if ($connection->connect_error) {
    die("Connection failed: " . mysqli_connect_error());
}
$sql = "SELECT id, title, content, bg_color FROM cards";
$result = $connection->query($sql);

if ($result->num_rows > 0) {
//data output of each row
    while ($row = $result->fetch_assoc()) {
        echo "<div class=card style=background-color: " . $row["bg_color"] . "><h2>" . $row["title"] . "</h2>" . "<p>" . $row["content"]. "</p>" . "</div>";
            }
    } else {
        echo "0 results";
    }
?>

如何使十六进制颜色代码显示在引号内？

顺晟科技：

所以您可以混合使用单引号和双引号，这样内部引号就不会过早地终止外部引号。

<?php
$host = "localhost";
$username = "root";
$password = "";
$dbname = "bulletin_board";

//Create connection
$connection = new mysqli($host, $username, $password, $dbname);

//Check connection
if ($connection->connect_error) {
    die("Connection failed: " . mysqli_connect_error());
}
$sql = "SELECT id, title, content, bg_color FROM cards";
$result = $connection->query($sql);

if ($result->num_rows > 0) {
//data output of each row
    while ($row = $result->fetch_assoc()) {
        echo "<div class=card style=background-color: " . $row["bg_color"] . "><h2>" . $row["title"] . "</h2>" . "<p>" . $row["content"]. "</p>" . "</div>";
            }
    } else {
        echo "0 results";
    }
?>

或帮助使其更具可读性和可维护性

<?php
$host = "localhost";
$username = "root";
$password = "";
$dbname = "bulletin_board";

//Create connection
$connection = new mysqli($host, $username, $password, $dbname);

//Check connection
if ($connection->connect_error) {
    die("Connection failed: " . mysqli_connect_error());
}
$sql = "SELECT id, title, content, bg_color FROM cards";
$result = $connection->query($sql);

if ($result->num_rows > 0) {
//data output of each row
    while ($row = $result->fetch_assoc()) {
        echo "<div class=card style=background-color: " . $row["bg_color"] . "><h2>" . $row["title"] . "</h2>" . "<p>" . $row["content"]. "</p>" . "</div>";
            }
    } else {
        echo "0 results";
    }
?>