Echarts use cases

1. Echarts case website (since https://www.makeapie.com/ is closed, I found some alternatives)

1、http://chartlib.datains.cn/echarts

2、http://ppchart.com/#/

3、https://www.makeapie.cn/echarts

4、https://www.isqqw.com/

5、https://madeapie.com/#/

2. Solve the warning:There is a chart instance already initialized on the dom.

const dom = document.getElementById('barChart') as HTMLCanvasElement
letmyChart = echarts.getInstanceByDom(dom)!
// 如果不存在，就进行初始化
if (myChart == null) {
    
    
  myChart = echarts.init(dom)
}
myChart.setOption(option)