Question

请有人帮助我......在我最近的项目中，这个功能运行得很好，但现在它没有... CSS规则@media屏幕和（max-width：800px）只是不起作用。我看过整个互联网并且无法找到解决方案，有人可以帮助我吗？

html body{
    background-color: #fafafa;
    height: 100%;
}
@media screen and (max-width: 800px) {
    html body{background-color:#fff;}
}

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
    <head>
        <meta name="viewport" content="width=device-width, initial-scale=1.0" />
        
        <!-- Latest compiled and minified CSS -->
        <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">

        <!-- Optional theme -->
        <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap-theme.min.css" integrity="sha384-rHyoN1iRsVXV4nD0JutlnGaslCJuC7uwjduW9SVrLvRYooPp2bWYgmgJQIXwl/Sp" crossorigin="anonymous">

        <!-- Latest compiled and minified JavaScript -->
        <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js" integrity="sha384-Tc5IQib027qvyjSMfHjOMaLkfuWVxZxUPnCJA7l2mCWNIpG9mGCD8wGNIcPD7Txa" crossorigin="anonymous"></script>
        
        <!-- Google Roboto Fonts -->
        <link href="http://fonts.googleapis.com/css?family=Roboto:400,400italic,300italic,300,100italic,100,500,500italic,700,700italic,900,900italic&subset=cyrillic,cyrillic-ext,latin,latin-ext" rel="stylesheet" type="text/css">
        
        <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
        
        <link href="css/style.css" rel="stylesheet" type="text/css" />
        
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 
    </head>
    <body>
        
        <!-- My code -->
      
        <!-- jQuery (necessary for Bootstrap's JavaScript plugins) -->
        <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script>
    </body>
</html>

Answer 1

您的代码段中的一个问题是您没有包含jQuery。 Bootstrap需要jQuery才能执行。

我已经包含了jQuery，仅用于调试目的，我已将max-width缩减为150 px，现在它正常工作。

提示：在chrome中打开调试窗口（右键单击＆gt;检查或按F12），当您重新设置窗口时，宽度将显示在顶部。

html body{
    background-color: #fff;
    height: 100%;
}
@media screen and (max-width: 150px) {
    html body{background-color:#000;}
}

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
    <head>
        <meta name="viewport" content="width=device-width, initial-scale=1.0" />
        <script src="https://code.jquery.com/jquery-3.1.0.min.js"></script>
        <!-- Latest compiled and minified CSS -->
        <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">

        <!-- Optional theme -->
        <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap-theme.min.css" integrity="sha384-rHyoN1iRsVXV4nD0JutlnGaslCJuC7uwjduW9SVrLvRYooPp2bWYgmgJQIXwl/Sp" crossorigin="anonymous">

        <!-- Latest compiled and minified JavaScript -->
        <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js" integrity="sha384-Tc5IQib027qvyjSMfHjOMaLkfuWVxZxUPnCJA7l2mCWNIpG9mGCD8wGNIcPD7Txa" crossorigin="anonymous"></script>
        
        <!-- Google Roboto Fonts -->
        <link href="http://fonts.googleapis.com/css?family=Roboto:400,400italic,300italic,300,100italic,100,500,500italic,700,700italic,900,900italic&subset=cyrillic,cyrillic-ext,latin,latin-ext" rel="stylesheet" type="text/css">
        
        <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
        
        <link href="css/style.css" rel="stylesheet" type="text/css" />
        
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 
    </head>
    <body>
        
        <!-- My code -->
      
        <!-- jQuery (necessary for Bootstrap's JavaScript plugins) -->
        <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script>
    </body>
</html>

@media屏幕和（最大宽度：800px）无法正常工作，遍布互联网

1 个答案: