我浏览了 Zigfu 网站上制作用户雷达的初始教程。我无法让这个雷达在画布元素中工作。
我想在画布中使用绘图方法，所以我不希望它在容器中。
这是我到目前为止直接取自教程的代码。非常感谢您的阅读！
function loaded() {
var radardiv = document.getElementById('container');
var radar = {
onuserfound: function (user) {
var userdiv = document.createElement('div');
userdiv.className = 'user';
user.radarelement = userdiv;
radardiv.appendChild(user.radarelement);
},
onuserlost: function (user) {
radardiv.removeChild(user.radarelement);
},
ondataupdate: function (zigdata){
for (var userid in zigdata.users){
var user = zigdata.users[userid];
var pos = user.position;
//console.log(pos);
var el = user.radarelement;
var parentElement = el.parentNode;
var zrange = 2000;
var xrange = 700;
var pixelwidth = parentElement.offsetWidth;
var pixelheight = parentElement.offsetHeight;
var heightscale = pixelheight / zrange;
var widthscale = pixelwidth / xrange;
el.style.left = (((pos[0] / xrange) + 0.5) * pixelwidth - (el.offsetWidth / 2)) + "px";
el.style.top = ((pos[2] / zrange) * pixelheight - (el.offsetHeight / 2)) - 150 + "px";
}
}
};
zig.addListener(radar);
}
document.addEventListener('DOMContentLoaded', loaded, false);
<body>
<div id = 'container'></div>
</body>
</html>
<style>
div#container {
width: 800px;
height: 600px;
border: 1px solid black;
overflow: hidden;
}
div.user {
position: relative;
width: 10px;
height: 10px;
background-color: red;
}