NEZ-3122 fix：Dashboard创建图表中Null Value选择connected时，图表效果显示不正确

nezha-fronted/src/components/chart/chart/chartTimeSeries.vue

@@ -501,7 +501,6 @@ export default {
             } else if (item.yAxisIndex == 1) {
               className = 'yAxis-icon nz-icon nz-icon-youzongzhou'
             }
-
             str += `
             <div class="tooltip__row" title="${seriesName}">
               <div class="row__label">
@@ -538,7 +537,6 @@ export default {
               }
               color = self.stackTotalColorRight
             }
-
             str += `
             <div class="tooltip__row">
               <div class="row__label" title="${self.$t('dashboard.dashboard.chartTotal')}">

nezha-fronted/src/components/chart/chartMixin.js

@@ -117,9 +117,8 @@ export default {
           if (!this.dataLink.length) {
             s.cursor = 'default'
           }
-
-          if (s.param && s.param.nullType) {
-            s.connectNulls = s.param.nullType !== 'null'
+          if (chartInfo.param && chartInfo.param.nullType) {
+            s.connectNulls = chartInfo.param.nullType !== 'null'
           } else {
             s.connectNulls = false
           }

nezha-fronted/src/components/common/js/tools.js

@@ -1061,6 +1061,9 @@ export function hideTableTooltip () {
 
 /* 数字转换保留小数，数字很小时转为科学计数法, dot为保留几位小数 */
 export function formatScientificNotation (value, dot = 2) {
+  if (isNaN(value) || value === null) {
+    return value
+  }
   let val = value ? parseFloat(Number(value).toFixed(dot)) : 0
   if (val === 0) {
     val = Number(value).toPrecision(dot + 1)