实现一个可拖拽的div 

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>实现可拖拽的div</title>
    <style>
        body {
            margin: 0;
            padding: 0;
        }

        div {
            width: 100px;
            height: 100px;
            border: 1px solid red;
            position: absolute;
            top: 0;
            left: 0;
        }
    </style>
</head>

<body>
    <div id="div"></div>
</body>
<script>
    /*  
      注意事项：
        1.clientX是没有单位的，left是有单位的
        2.mousemove事件放到document上，而不是放到div上，是为了解决拖动div过快导致div突然停下来的问题
    */
    let drag = false, position = null
    div.addEventListener('mousedown', (e) => {
        drag = true;
        position = [e.clientX, e.clientY]
    })
    document.addEventListener('mousemove', (e) => {
        if (!drag) {
            return;
        }
        let x = e.clientX;
        let y = e.clientY;
        let dx = x - position[0]
        let dy = y - position[1]
        let left = parseInt(div.style.left || 0) 
        let top = parseInt(div.style.top || 0)
        div.style.left = left + dx + 'px';
        div.style.top = top + dy + 'px';
        position = [x, y]
    })
    document.addEventListener('mouseup', () => {
        drag = false
    })
</script>

</html>

实现效果

posted @ 2021-01-24 18:00  时光傀儡师  阅读(382)  评论(0)  编辑  收藏  举报