HTML5特性检測:



   1.检測全局对象:诸如window或navigator是否拥有特定的属性



   2.创建元素:检測该元素的DOM对象是否拥有特定的属性



   3.创建元素:检測该元素的DOM对象是否拥有特定的方法



   4.创建元素:赋予该元素的DOM对象设定的属性值,检測浏览器



              是否保留该属性值



Modernizr:HTML5特性检測库,用于检測浏览器是否支持HTML5



         和CSS3特性.下载Development版http://www.modernizr.com/



eg.   



Ⅰ.检測浏览器是否支持canvas API



1. html5特性检測2:



<html>



<head>



<title>Dive into HTML5</title></head>



<body>



<script>



function supports_canvas() {



return !!document.createElement('canvas').getContext;}



alert(supports_canvas());



</script></body></html>



2.使用modernizr库提供的方法检測



<html><head><meta charset="utf-8">



<title>Dive into HTML5</title>



<script src="modernizr.custom.57110.js" ></script>



</head><body><script>



if (Modernizr.canvas) {



alert("OK"); }   // let's draw some shapes!



 else {



alert("no");}     // no native canvas support available



</script></body></html>



Ⅱ.检測浏览器是否支持HTML5 viedo



1.使用HTML5特性检測2



function supports_video(){



       return !!document.CreateElement(“video”).canPlayType;}



2.使用modernizr库提供的方法检測



if(modernizr.video){



let's play some video!}



else{



// no native video support available



// maybe check for QuickTime or Flash instead }



Ⅲ.检測浏览器是否支持某种视频格式



一.检測MPEG-4容器里的h.264编码格式的视频和AACLC格式的音频(mac和Iphone支持)



1.使用HTML5检測特性3



     function supports_h264_baseline_video(){



        if(!supports_video()){return false;}



        var v=document.createElement(“video”);



        return v.canPlayType(‘video/mp4;codecs=”avc1.42E01E,mp4a.40.2”’);}



canPlayType()方法返回一个字符串:



“probably”表示浏览器有充分把握能够播放此格式



 “maybe”表示浏览器可能播放此格式



“”(空字符串)表示浏览器无法播放此格式



二.检測Ogg容器内Theora编码格式的视频和Vorbis编码格式的音频(Mozilla Firefox等开源浏览器支持)



1.使用HTML5检測特性3



  function supports_ogg_theora_video(){



         if(!supports_video()){return false;}



         var v=document.createElement(“video”);



         return v.canPlayType(‘video/ogg;codecs=”theora,vorbis”’);}



三.检測 Matroska容器内webM视频编码格式和Vorbis编码格式的音频



1.使用HTML5检測特性3



function supports_webm_video() {



if (!supports_video()) { return false; }



var v = document.createElement("video");



return v.canPlayType('video/webm; codecs="vp8, vorbis"');



使用modernizr库提供的方法检測浏览器是否支持各种HTML5格式



    if (Modernizr.video) {



// let's play some video! but what kind?



if (Modernizr.video.ogg) {



// try Ogg Theora + Vorbis in an Ogg container



} else if (Modernizr.video.h264){// try H.264 video + AAC audio in an MP4 container



}}



Ⅳ.检測浏览器是否支持本地存储。

1.检測方法1

function supports_local_storage() {

return ('localStorage' in window) && window['localStorage'] !== null;

}



2.使用modernizr库

     if (Modernizr.localstorage) {

               // window.localStorage is available!}

       else {

           // no native support for local storage :(

          // maybe try Gears or another third-party solution

}



Ⅴ.检測浏览器是否支持Web Workers。

1.检測方法1

   function supports_web_workers() {

return !!window.Worker;

}

2.使用modernizr库

    if (Modernizr.webworkers) {

// window.Worker is available!

} else {

// no native support for web workers :(

// maybe try Gears or another third-party solution

}

Ⅵ.检測浏览器是否支持离线web应用(Offline Web Applications)

 1.检測方法1

    function supports_offline() {

return !!window.applicationCache;

}

2.使用modernizr库

  if (Modernizr.applicationcache) {

// window.applicationCache is available!

} else {

// no native support for offline :(

// maybe try Gears or another third-party solution

}

Ⅶ.检測浏览器是否支持地理位置应用

 1.检測方法1

    function supports_geolocation() {

return !!navigator.geolocation;

}

2.使用modernizr库

  if (Modernizr.geolocation) {

// let's find out where you are!

} else {

// no native geolocation support available :(

// maybe try Gears or another third-party solution

}

Ⅷ。检測浏览器是否支持输入框类型

1.检測方法4

function supports_inputtypes{

   var i = document.createElement("input");

   i.setAttribute("type", "color");

   return i.type !== "text";

}

2.使用modernizr库

  if (!Modernizr.inputtypes.date) {

// no native support for <input type="date"> :(

// maybe build one yourself with

// Dojo

// or jQueryUI

}

Ⅸ.检測浏览器是否支持站位文本(Placeholder Text)

   1.检測方法2

      function supports_input_placeholder() {

var i = document.createElement('input');

return 'placeholder' in i;

}

2.使用modernizr库

  if (Modernizr.input.placeholder) {

// your placeholder text should already be visible!

} else {

// no placeholder support :(

// fall back to a scripted solution

}

Ⅹ。检測浏览器是否支持自己主动聚焦

    1.检測方法2

        function supports_input_autofocus() {

var i = document.createElement('input');

return 'autofocus' in i;

}

2.使用modernizr库

if (Modernizr.input.autofocus) {

// autofocus works!

} else {

// no autofocus support :(

// fall back to a scripted solution

}

 Ⅺ。检測浏览器是否支持HTML5微数据API

 1.检測方法1

        function supports_microdata_api() {

return !!document.getItems;

}

04-01 12:49