我正在制作一个小型在线应用程序，需要用户输入一些选项，网站将根据他们的输入更改其背景和类似功能。
但是，我无法通过 JavaScript 代码更改任何文档样式属性。
我错过了什么吗？
let bgType = prompt("Which type of background do you want? Color or image: ");
if (bgType == "color" || bgType == "Color") {
let colBg = prompt("Enter the color you want");
document.getElementById("background").style.backgroundColor = colBg; // I've tried putting default colors here for testing, but those didn't work either
} else if (bgType == "image" || bgType == "Image") {
let imgBg = prompt("Enter the number of the image you want (1-3): ");
document.getElementById("background").style.backgroundColor = ""; // Unfinished
}
如果需要，这里还有 HTML 和 CSS 代码 HTML：
<!DOCTYPE html>
<html>
<head>
<meta charset='utf-8'>
<meta http-equiv='X-UA-Compatible' content='IE=edge'>
<title>Greeting card generator</title>
<meta name='viewport' content='width=device-width, initial-scale=1'>
<link rel='stylesheet' type='text/css' media='screen' href='gfx.css'>
</head>
<body>
<script src='script.js'></script>
<div id="background" class="content">
<!-- <img src="Temp1.jpg" alt="Greeting card image"> -->
<h1 id="Title" class="text">
Sample title text
</h1>
<h2 id="Name" class="text">
Sample name text
</h2>
<h3 id="Message" class="text">
Sample message text
</h3>
</div>
</body>
</html>
CSS：
html, body {
height: 100%;
margin: 0;
}
#background {
width: 100%;
min-height: 100%;
background-image: url();
background-color: white;
background-size: cover;
background-position: center;
background-repeat: no-repeat;
}
.text {
font-family: verdana;
text-align: center;
}
#Title {
padding-top: 20%;
}
问题是脚本在 DOM 完全构建并且您想要设置样式的元素实际存在之前运行。 您需要将
<script>标签移动到
<body> <body>
<div id="background" class="content">
<!-- <img src="Temp1.jpg" alt="Greeting card image"> -->
<h1 id="Title" class="text">Sample title text</h1>
<h2 id="Name" class="text">Sample name text</h2>
<h3 id="Message" class="text">Sample message text</h3>
</div>
<script src="script.js"></script>
</body>
的开头添加“#”即可。像这样使用
<script>
let bgType = prompt("Which type of background do you want? Color or image: ");
if (bgType == "color" || bgType == "Color") {
let colBg = prompt("Enter the color you want");
document.getElementById("background").style.backgroundColor = `#${colBg}`; // I've tried putting default colors here for testing, but those didn't work either
} else if (bgType == "image" || bgType == "Image") {
let imgBg = prompt("Enter the number of the image you want (1-3): ");
document.getElementById("background").style.backgroundColor = ""; // Unfinished
}
</script>
确保您的输入始终采用类似#fff
的颜色值
#。如果发送颜色的名称，则必须发送所有名称。就像这样：
color:#000color:Blackdocument.getElementById("id_quantity").style.fontSize = "25px";