ECharts实现折现图的拐点为空心圆圈

效果：

let option = {
        tooltip: {
          trigger: 'axis',
          axisPointer: {
            type: 'cross',
            crossStyle: {
              color: '#999'
            }
          },
          formatter: function (params) {
            return '';
          }
        },
        grid: {
          left: 10,
          right: 40,
          bottom: 10,
          top: 45,
          containLabel: true
        },
        legend: {
          top: 30,
          right: 40,
          itemWidth: 10,
          itemHeight: 10,
          textStyle: {
            color: '#aaa'
          },
          data: [
            {
              name: '当前',
              icon: ''
            },
            {
              name: '同比',
              icon: ''
            },
            {
              name: '日均',
              icon: 'line'
            },
          ]
        },
        xAxis: [
          {
            type: 'category',
            data: ['2022-10-25'],
            axisPointer: {
              type: 'shadow'
            },
            axisLabel: {
              color: '#838383',
              fontSize: 12,
              interval: 0,
              // rotate: 35
            },
            axisTick: { show: false },
            axisLine: {
              show: true,
              lineStyle: {
                color: '#eee',
              }
            }
          }
        ],
        yAxis: [
          {
            type: 'value',
            axisLine: {
              show: true,
              lineStyle: {
                color: 'transparent'
              }
            },
            axisTick: {
              show: false
            },
            splitLine: {
              show: false
            },
            axisLabel: {
              formatter: '{value}%',
              color: '#B2BCCB',
              fontSize: 10
            },
            position: 'left',
            splitLine: {
              show: true,
              lineStyle: {
                color: '#F5F5F6',
                type: 'dashed'//虚线
              }
            }
          }
        ],
        series: [
          {
            name: '当前',
            type: 'line',
            data: [{
                symbol: 'emptyCircle',
                symbolSize: 8,
                value: 0
            }],
            itemStyle: {
              color: '#8ED53B',
              deccal: {
                symbol: 'rect',

              }
            },
          },
          {
            name: '同比',
            type: 'line',
            data:  [{
                symbol: 'emptyCircle',
                symbolSize: 8,
                value: 0
            }],
            itemStyle: {
              color: '#438AFE'
            },
          },
          {
            name: '日均',
            type: 'line',
            data:  [{
                symbol: 'emptyCircle',
                symbolSize: 8,
                value: 0
            }],
            itemStyle: {
              color: '#D0D5DB',
              opacity: 0,
            },
            lineStyle: {
              type: 'dashed'
            }
          },
        ]
      };

在option-》series-》data-》symbol设置为emptyCircle