我希望跟踪鼠标光标的位置，周期性地每t秒。因此，从本质上讲，当一个页面加载时，这个跟踪器应该开始，(比如说)每100毫秒，我应该得到posX和posY的新值，并将其打印到表单中。
我尝试了下面的代码-但值不会刷新-只有posX和posY的初始值显示在表单框中。有什么办法能让它运行起来吗?
<html>
<head>
<title> Track Mouse </title>
<script type="text/javascript">
function mouse_position()
{
var e = window.event;
var posX = e.clientX;
var posY = e.clientY;
document.Form1.posx.value = posX;
document.Form1.posy.value = posY;
var t = setTimeout(mouse_position,100);
}
</script>
</head>
<body onload="mouse_position()">
<form name="Form1">
POSX: <input type="text" name="posx"><br>
POSY: <input type="text" name="posy"><br>
</form>
</body>
</html>
如果只是想直观地跟踪鼠标移动:
<!DOCTYPE html>
<html>
<head>
<title></title>
</head>
<style type="text/css">
* { margin: 0; padding: 0; }
html, body { width: 100%; height: 100%; overflow: hidden; }
</style>
<body>
<canvas></canvas>
<script type="text/javascript">
var
canvas = document.querySelector('canvas'),
ctx = canvas.getContext('2d'),
beginPath = false;
canvas.width = window.innerWidth;
canvas.height = window.innerHeight;
document.body.addEventListener('mousemove', function (event) {
var x = event.clientX, y = event.clientY;
if (beginPath) {
ctx.lineTo(x, y);
ctx.stroke();
} else {
ctx.beginPath();
ctx.moveTo(x, y);
beginPath = true;
}
}, false);
</script>
</body>
</html>
我没有足够的声誉来发布评论回复，但采用了TJ克劳德的出色回答，并在100毫秒的计时器上完整地定义了代码。(他把一些细节留给大家想象。)
感谢OP的提问，感谢TJ的回答!你们俩都帮了大忙。代码嵌入在下面，作为isbin的镜像。
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Example</title>
<style>
body {
height: 3000px;
}
.dot {
width: 2px;
height: 2px;
background-color: black;
position: absolute;
}
</style>
</head>
<body>
<script>
(function() {
"use strict";
var mousePos;
document.onmousemove = handleMouseMove;
setInterval(getMousePosition, 100); // setInterval repeats every X ms
function handleMouseMove(event) {
var eventDoc, doc, body;
event = event || window.event; // IE-ism
// If pageX/Y aren't available and clientX/Y are,
// calculate pageX/Y - logic taken from jQuery.
// (This is to support old IE)
if (event.pageX == null && event.clientX != null) {
eventDoc = (event.target && event.target.ownerDocument) || document;
doc = eventDoc.documentElement;
body = eventDoc.body;
event.pageX = event.clientX +
(doc && doc.scrollLeft || body && body.scrollLeft || 0) -
(doc && doc.clientLeft || body && body.clientLeft || 0);
event.pageY = event.clientY +
(doc && doc.scrollTop || body && body.scrollTop || 0) -
(doc && doc.clientTop || body && body.clientTop || 0 );
}
mousePos = {
x: event.pageX,
y: event.pageY
};
}
function getMousePosition() {
var pos = mousePos;
if (!pos) {
// We haven't seen any movement yet, so don't add a duplicate dot
}
else {
// Use pos.x and pos.y
// Add a dot to follow the cursor
var dot;
dot = document.createElement('div');
dot.className = "dot";
dot.style.left = pos.x + "px";
dot.style.top = pos.y + "px";
document.body.appendChild(dot);
}
}
})();
</script>
</body>
</html>
