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<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
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<body>
<!-- <img id="ball" src="https://js.cx/clipart/ball.svg" width = "100px" height = "100px" >
<object data="https://js.cx/clipart/ball.svg" width="100" height="100" type="image/svg+xml" codebase="http://www.adobe.com/svg/viewer/imstall/" /> -->
<img id="ball" src = "https://www.baidu.com/img/bd_logo1.png?qua=high&where=super" alt = "logo">
<div>helloworld</div>
<script>
const ball=document.querySelector("#ball")
ball.onmousedown = function(event) {
let shiftX = event.clientX - ball.getBoundingClientRect().left;
let shiftY = event.clientY - ball.getBoundingClientRect().top;
ball.style.position = ‘absolute‘;
ball.style.zIndex = 1000;
document.body.append(ball);
moveAt(event.pageX, event.pageY);
// 移动现在位于坐标 (pageX, pageY) 上的球
// 将初始的偏移考虑在内
function moveAt(pageX, pageY) {
ball.style.left = pageX - shiftX + ‘px‘;
ball.style.top = pageY - shiftY + ‘px‘;
}
function onMouseMove(event) {
moveAt(event.pageX, event.pageY);
}
// 在 mousemove 事件上移动球
document.addEventListener(‘mousemove‘, onMouseMove);
// 放下球，并移除不需要的处理程序
ball.onmouseup = function() {
document.removeEventListener(‘mousemove‘, onMouseMove);
ball.onmouseup = null;
};
};
ball.ondragstart = function() {
return false;
};
</script>
</body>
</html>
原文：https://www.cnblogs.com/kinologic/p/15093246.html