Vue根据directive指令进行div拖拽，解决拖拽drag后触发点击click事件，解决directive无法获取this的问题
开始做拖拽上网查了一些资料，拖拽效果容易做到，但是拖拽后会触发默认的点击事件，于是又上网搜索找到了方法，将click后的事件移入到directive中处理，然后发现无法获取到环境中的this，下面以拖拽button做为示例：
html
<el-button v-drag>text</el-button>
js
export default {directives: {drag(el,binding,vnode) {let clientOffset = {};el.onmousedown = function(e) {var disx = e.pageX - el.offsetLeftvar disy = e.pageY - el.offsetTopclientOffset.clientX = event.clientX;clientOffset.clientY = event.clientY;document.onmousemove = function (e) {el.style.left = e.pageX - disx + 'px'el.style.top = e.pageY - disy + 'px'}document.onmouseup = function() {document.onmousemove = document.onmouseup = null}}el.addEventListener('mouseup', (event) => {//鼠标抬起后的事件，判断是拖拽还是点击let clientX = event.clientX;let clientY = event.clientY;if (clientX === clientOffset.clientX && clientY === clientOffset.clientY) { //这里触发点击事件，将click方法移入这里let that = vnode.context //通过vnode参数来获取this,此时的that就可以获取到js中的this} else { return//这里是拖拽事件}})}},}
