js draggable 拖拽效果
- drag 拖拽中
- dragstart 开始拖拽
- dragover 拖拽悬浮时触发
- dragenter 拖入目标节点
- dragleave 离开源节点
- drop 落进目标节点
- event.dataTransfer.setData 拖拽时传输数据，可用于dragstart中
- event.dataTransfer.getData 拖拽时传输数据，可用于drop中
demo
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<style>
#draggable {
width: 200px;
height: 20px;
text-align: center;
background: lightcoral;
}
.dropzone {
width: 200px;
height: 20px;
background: aqua;
margin-bottom: 10px;
padding: 10px;
}
</style>
<body>
<div id="wrapper">
<div class="dropzone">
<div id="draggable" draggable="true">
a draggable div
</div>
</div>
<div class="dropzone"></div>
<div class="dropzone"></div>
<div class="dropzone"></div>
</div>
<script>
var dragged;
const wDom = document.getElementById('wrapper')
// 开始拖拽，也可用drag，不过drag，dragover在拖起的时候会持续触发， dragstart只触发一次
wDom.addEventListener('dragstart', (e) => {
dragged = e.target
e.target.style.opacity = 0.5
event.dataTransfer.setData('text/plain', JSON.stringify({}))
})
// 拖拽悬浮
wDom.addEventListener('dragover', (e) => {
e.preventDefault()
})
// 拖拽结束，还原源节点的透明度
wDom.addEventListener('dragend', (e) => {
e.target.style.opacity = ""
})
// 进入目标节点，高亮目标节点
wDom.addEventListener('dragenter', (e) => {
if (e.target.className === 'dropzone') {
e.target.style.background = "red"
}
})
// 离开源节点
wDom.addEventListener('dragleave', (e) => {
if (e.target.className === 'dropzone') {
e.target.style.background = ""
}
})
// 放进目标节点，取消目标节点的高亮，转移dom
wDom.addEventListener('drop', (e) => {
if (e.target.className === 'dropzone') {
const data = event.dataTransfer.getData('text/plain')
e.target.style.background = ""
dragged.parentNode.removeChild(dragged)
e.target.appendChild(dragged)
}
})
</script>
</body>
</html>
