feat：完善功能

src/hooks/echart.js

@@ -3,21 +3,21 @@ import * as echarts from 'echarts'
 import { guid } from '@/utils/util'
 
 export function useEchart() {
-  let chart = null
+  let chart = ref(null)
   let id = ref(guid())
   const initChart = () => {
     const dom = document.getElementById(id.value)
-    chart = echarts.init(dom)
+    chart.value = echarts.init(dom)
   }
   const setOption = (params, update = false) => {
-    chart.setOption(params, update)
+    chart.value.setOption(params, update)
   }
   const dispose = () => {
-    chart.dispose()
-    chart = null
+    chart.value.dispose()
+    chart.value = null
   }
   const resize = () => {
-    chart.resize()
+    chart.value.resize()
   }
   onMounted(() => {
     initChart()