update：相机缩放案例代码的修改

src/examples/camera/cameraZoom/cameraZoom-function.js

-let viewer;
-export function addCameraZoom() {
-    const script = document.createElement('script');
-    script.src = 'https://cesium.com/downloads/cesiumjs/releases/1.99/Build/Cesium/Cesium.js';
-    script.onload = () => {
-        window.Cesium.Ion.defaultAccessToken = 'eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJqdGkiOiI3Njg4ZWU5Yi1iZDhiLTRhYmUtOTRiYS04YjM5NmUwNjVmMDMiLCJpZCI6MjI3MzQ3LCJpYXQiOjE3MjA1MjA4Mjh9.E5XW4LnwgfVAaBC-znaYr61m4yK0-j2qEQhi9qwFFPE'
-
-        viewer = new window.Cesium.Viewer('cesiumContainer', {
-            infoBox: false,
-        });
- 
-    };
-    document.head.appendChild(script);
-
-    const link = document.createElement('link');
-    link.rel = 'stylesheet';
-    link.href = 'https://cesium.com/downloads/cesiumjs/releases/1.119/Build/Cesium/Widgets/widgets.css';
-    document.head.appendChild(link);
-}
-
-// 获取视图中心点
-function  pickCenter() {
+export function zoomByBound(viewer, flag){
     var ellipsoid = viewer.camera.pickEllipsoid(new Cesium.Cartesian2(
         viewer.canvas.clientWidth / 2,
         viewer.canvas.clientHeight / 2));
     var curPosition = Cesium.Ellipsoid.WGS84.cartesianToCartographic(ellipsoid);
     var lon = curPosition.longitude * 180 / Math.PI;
     var lat = curPosition.latitude * 180 / Math.PI;
-    return {
-        lon: lon,
-        lat: lat
-    };
-}
-export function zoomByBound(flag){
-    const center = pickCenter()
     var height = viewer.camera.positionCartographic.height;
     const camera = viewer.camera;
-    var boundingSph = new Cesium.BoundingSphere(Cesium.Cartesian3.fromDegrees(center.lon, center.lat, 1000), height);
+    var boundingSph = new Cesium.BoundingSphere(Cesium.Cartesian3.fromDegrees(lon, lat, 1000), height);
     var moveRate = 0;
     if(flag){
         moveRate = 0.5

src/examples/camera/cameraZoom/cameraZoom.vue

 <template>
     <div id="cesiumContainer" class="cesium-container"></div>
     <div class="btn-class">
-        <button @click="zoomByBound(1)">放大相机视角</button>
-        <button @click="zoomByBound(0)">缩小相机视角</button>
+        <button @click="zoomByBound(viewer, 1)">放大相机视角</button>
+        <button @click="zoomByBound(viewer, 0)">缩小相机视角</button>
     </div>
 </template>
+
 <script setup>
 import { onMounted } from 'vue';
-import { addCameraZoom, zoomByBound } from './function';
+import { zoomByBound } from './function';
+
+let viewer;
+
 onMounted(() => {
-    addCameraZoom()
+    const script = document.createElement('script');
+    script.src = 'https://cesium.com/downloads/cesiumjs/releases/1.99/Build/Cesium/Cesium.js';
+    script.onload = () => {
+        window.Cesium.Ion.defaultAccessToken = 'eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJqdGkiOiI3Njg4ZWU5Yi1iZDhiLTRhYmUtOTRiYS04YjM5NmUwNjVmMDMiLCJpZCI6MjI3MzQ3LCJpYXQiOjE3MjA1MjA4Mjh9.E5XW4LnwgfVAaBC-znaYr61m4yK0-j2qEQhi9qwFFPE'
+
+        viewer = new window.Cesium.Viewer('cesiumContainer', {
+            infoBox: false,
+        });
+
+    };
+    document.head.appendChild(script);
+    const link = document.createElement('link');
+    link.rel = 'stylesheet';
+    link.href = 'https://cesium.com/downloads/cesiumjs/releases/1.119/Build/Cesium/Widgets/widgets.css';
+    document.head.appendChild(link);
 });
 </script>