canvas:通过脚本绘制图形
<canvas id="myCanvas">你的浏览器不支持 HTML5 canvas 标签。</canvas>
<script>
var c = document.getElementById('myCanvas');
var ctx = c.getContext('2d'); //返回对象,该对象上有绘制图形的方法和属性
ctx.fillStyle = '#FF0000';
ctx.fillRect(0, 0, 80, 100);
</script>
SVG:可缩放矢量图形
<svg>
<rect width="200px" height="200px" fill="blue"></rect>
</svg>
<div id="box" ondragover="allowDrage" ondrop="drop"></div>
<img src="./p2869446365.jpg" draggable="true" id="img" ondragstart="dragStart"/>
<script type="text/javascript">
function dragStart(ev){
ev.dataTrasfer.setData("Text",ev.target.id)
}
function allowDrage(ev){
ev.preventDeafault();
}
function drop(ev){
ev.preventDeafault();
var data = ev.dataTrasfer.getData("Text");
var img = document.getElementById("img");
ev.targer.appendChild(img);
}
</script>
<video width="320" height="240" controls>
<source src="movie.mp4" type="video/mp4">
<source src="movie.ogg" type="video/ogg">
</video>
<audio controls>
<source src="horse.ogg" type="audio/ogg">
<source src="horse.mp3" type="audio/mpeg">
</audio>
<button id="btn">click</button>
<script>
var btn = document.getElementById("btn");
btn.addEventListener("click",()=>{
var geoloc = window.navigator.geolocation;
geoloc.getCurrentPosition(
(success)=>console.log('success' , success),
(err)=>console.log('err' , err),
{timeout:5000}
)
})
</script>
一个5M大小的针对于前端页面的数据库,值类型限定为string类型,这个在对我们日常比较常见的JSON对象类型需要一些转换
//存
var ls = window.localStorage || window.sessionStorage
ls.setItem("key",value)
//取
ls.getItem("key")
//改
ls.key = value
//删全部
ls.clear()
//删某个
ls.removeItem("key")
https://blog.csdn.net/GoodburghCottage/article/details/125978987