1.在项目src目录下可以新建一个文件夹 ，取名为 directive ,在该目录中创建drag.js , 代码如下：
/**
* @file 自定义拖拽命令
*/
import Vue from 'vue';
export default {
bind(el: any) {
el.style.position = 'absolute';
el.style.zIndex = el.style.zIndex || '3000';
},
inserted(el: any) {
// 设置元素初始位置
const boundingClientRect = el.getBoundingClientRect();
el.style.left = boundingClientRect.x + 'px';
el.style.top = boundingClientRect.y + 'px';
// 将拖拽元素置于body子元素，防止被relative的父元素遮挡
document.body.appendChild(el);
let originX: number;
let originY: number;
const mouseDownHandler = (evt: MouseEvent) => {
originX = evt.clientX - el.offsetLeft;
originY = evt.clientY - el.offsetTop;
el.style.cursor = 'pointer';
};
const mouseMoveHandler = (evt: MouseEvent) => {
if (evt.buttons === 1 && originX && originY) {
el.style.left = evt.clientX - originX + 'px';
el.style.top = evt.clientY - originY + 'px';
}
};
const mouseUpHandler = () => {
el.style.cursor = 'default';
};
el.addEventListener('mousedown', mouseDownHandler);
el.addEventListener('mousemove', mouseMoveHandler);
el.addEventListener('mouseup', mouseUpHandler);
el.__mouseDownHandler__ = mouseDownHandler;
el.__mouseMoveHandler__ = mouseMoveHandler;
el.__mouseUpHandler__ = mouseUpHandler;
},
unbind(el: any) {
el.removeEventListener('mousedown', el.__mouseDownHandler__);
el.removeEventListener('mousemove', el.__mouseMoveHandler__);
el.removeEventListener('mouseup', el.__mouseUpHandler__);
// 当父组件销毁触发unbind的时候需要手动删除这个节点，不然会一直存留在body中
el.parentNode.removeChild(el);
}
}
2.在当前文件夹里新建index.js
import drag from "./drag .js";
var xhDirective = {
drag :drag ,
}
const install = function(Vue) {
Object.keys(xhDirective).forEach(key => {
Vue.directive(key, xhDirective[key]);
});
};
const API = {
install,
...xhDirective
};
export default API;
3.在项目的主文件mian.js中引入，使用vue.use()来注册系统 的公共指令(部分代码)
import Vue from 'vue';
import directive from "./directive"
Vue.use(directive)
注：拖拽效果实现代码原文链接：https://blog.csdn.net/csu_passer/article/details/105709661
