将 ChartJS 与 React 一起使用时出现错误消息

Question

“元素类型无效：需要一个字符串（对于内置组件）或一个类/函数（对于复合组件）但得到：未定义。您可能忘记从定义它的文件中导出您的组件，或者您可能混淆了默认导入和命名导入。”

import React, {Component} from 'react'
var CanvasJSReact = require('./canvasjs.react');
var CanvasJSChart = CanvasJSReact.CanvasJSChart;

export class Chart1 extends Component {
    render() {
    const options = {
      title: {
        text: "Basic Column Chart in React"
      },
      data: [{              
                type: "column",
                dataPoints: [
                    { label: "Apple",  y: 10  },
                    { label: "Orange", y: 15  },
                    { label: "Banana", y: 25  },
                    { label: "Mango",  y: 30  },
                    { label: "Grape",  y: 28  }
                ]
       }]
   }

   return (
      <div>
        <CanvasJSChart options = {options}
            /* onRef = {ref => this.chart = ref} */
        />
      </div>
    );
  }
}

Answer 1

试试export default class Chart1 extends Component {