解决echarts图形由于label过长导致文字显示不全问题

series: [
      {
        name: seriesName || '数据来源',
        type: 'pie',
        clickable: false,　　　　　　 //是否开启点击
        minAngle: 15,           　　 //最小的扇区角度（0 ~ 360），用于防止某个值过小导致扇区太小影响交互
        avoidLabelOverlap: true,   //是否启用防止标签重叠策略
        hoverAnimation: false,　　  //是否开启 hover 在扇区上的放大动画效果。
        silent: true,　　　　　　　　//图形是否不响应和触发鼠标事件
        center: ['50%', '55%'],
        radius: ['20%', '45%'],
        labelLine: { //设置指示线的长度
normal: {
            length: 12,
            length2: 8}
        },
        label: {
          normal: {
            formatter: '{b|{b}}
{c}
{per|{d}%}  ',
            rich: {
              b: {
                fontSize: 12,
                height: 60,
                lineHeight: 20,
                align: 'center' //设置文字居中
},
              per: {
                color: '#eee',
                backgroundColor: '#334455',
                padding: [2, 4],
                borderRadius: 2,
                align: 'center',
              }
            }
          }
        },
        data: dataArray ||[
          { value: 0, name: '存量导入数据'},
          { value: 0, name: '异构导入数据'},
          { value: 0, name: '互联网导入数据'},
        ]
      }
    ]

label: {
    normal: {
      formatter(v) {
        let text =v.name;
        let value_format =v.value;
        let percent_format = Math.round(v.percent) + '%';
        if (text.length <= 6) {
          return`${text}
${value_format}
${percent_format}`;
        } else if (text.length > 6 && text.length <= 12) {
          return text = `${text.slice(0, 6)}
${text.slice(6)}
${value_format}
${percent_format}`
        } else if (text.length > 12 && text.length <= 18) {
          return text = `${text.slice(0, 6)}
${text.slice(6, 12)}
${text.slice(12)}
${value_format}
${percent_format}`
        } else if (text.length > 18 && text.length <= 24) {
          return text = `${text.slice(0, 6)}
${text.slice(6, 12)}
${text.slice(12, 18)}
${text.slice(18)}
${value_format}
${percent_format}`
        } else if (text.length > 24 && text.length <= 30) {
          return text = `${text.slice(0, 6)}
${text.slice(6, 12)}
${text.slice(12, 18)}
${text.slice(18, 24)}
${text.slice(24)}
${value_format}
${percent_format}`
        } else if (text.length > 30) {
          return text = `${text.slice(0, 6)}
${text.slice(6, 12)}
${text.slice(12, 18)}
${text.slice(18, 24)}
${text.slice(24, 30)}
${text.slice(30)}
${value_format}
${percent_format}`
        }
      },
      textStyle: {
        fontSize: 14}
    }
  },