JavaScript辅助响应式

js响应式

　　rem辅助响应式布局：其实就是指在HTML页面的大小不断变化的时候，里面的宽、高、字体等等也随之变化，主要是通过获取window.innerwidth的值来进行判断，7.5rem===100%===750px。

　　js响应式：就是通过navigator.userAgent.indexOf('Android')来获取不同的客户端版本，例如‘Android’,然后使用 window.resize()=function(){} 返回不同样式给客户端.

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title></title>
        <meta name="viewport" content="width=device-width,initial-scale=1,minimum-scale=1,maximum-scale=1,user-scalable=no" />
        <style type="text/css">
            *{
                margin: 0;
                padding: 0;
                box-sizing: border-box;
            }
            #div1{
                /*7.5rem===100%*/
                width: 3.75rem;
                height: 1rem;
                background: skyblue;
                font-size: .7rem;
            }
        </style>
    </head>
    <body>
        <div id="div1">
            helloworld
        </div>
        <script>
//        window.innerWidth === 768 === 7.5
//        ?1rem === 768/7.5 === 1.x
//
            //html字体大小最小是10px,再小就不行。
            var html = document.querySelector('html')
            html.style.fontSize = window.innerWidth/7.5 + 'px'
            window.onresize = function(e){
                console.log(e)
                console.log(window)
                html.style.fontSize = window.innerWidth/7.5 + 'px'
            }
            
            
        </script>
    </body>
</html>

rem辅助响应式布局

<!DOCTYPE html>
<html class="mobile">
    <head>
        <meta charset="UTF-8">
        <title></title>
        <style type="text/css">
            .mobile #div1{
                background: skyblue;
            }
            .pc #div1{
                background: pink;
            }
            .pad #div1{
                background: salmon;
            }
            #div1{
                height: 100px;
            }
            .iphone #div1{
                background: yellow;
            }
            .android #div1{
                background: seagreen;
            }
        </style>
    </head>
    <body>
        <div id="div1" >
            
        </div>
        
        <script type="text/javascript">
            var html = document.querySelector('html')
            
            
            function resize(){
                var screneLength = window.innerWidth;
                html.style.fontSize = window.innerWidth/7.5 + 'px'
                if(screneLength>640&&screneLength<960){
                    html.className = 'pad'
                }else if(screneLength>=960){
                    html.className = 'pc'
                }else{
                    html.className = 'mobile'
                }
                
                
                
                if(navigator.userAgent.indexOf('Android')!==-1){
                    html.className = html.className + ' android'
                }else if(navigator.userAgent.indexOf('iPhone')!==-1){
                    html.className = html.className + ' iphone'
                }else if(navigator.userAgent.indexOf('iPad')!==-1){
                    html.className = html.className + ' ipad'
                }
            }
            resize()
            window.onresize = function(e){
                
                resize()
            }
        </script>
    </body>
</html>

js响应式