vue引入echart常见问题

导入echart正常，导入china.js就报错

• 原因是china.js里面导入echart的方法，在webpack中都无效所致，修改如下即可：

(function (root, factory) {
    if (typeof define === 'function' && define.amd) {
        // AMD. Register as an anonymous module.
        define(['exports', 'echarts'], factory);
    } else if (typeof exports === 'object' && typeof exports.nodeName !== 'string') {
        // CommonJS
        factory(exports, require('echarts'));
    } else {
        // Browser globals
        factory({}, root.echarts);

    }
}(this, function (exports, echarts) {
    var log = function (msg) {
        if (typeof console !== 'undefined') {
            console && console.error && console.error(msg);
        }
    }
    if (!echarts) {
      echarts = require('echarts/lib/echarts') // TODO 上述方法都无法引入echart，这里再导一遍
    }

    if (!echarts) {
        log('ECharts is not Loaded');
        return;

    }
    if (!echarts.registerMap) {
        log('ECharts Map is not loaded')
        return;
    }
    echarts.registerMap('china',