fix(h5): tabBar 切换丢失滚动位置

src/core/service/plugins/app/router-guard.js

@@ -15,7 +15,28 @@ function removeKeepAliveInclude (componentName) {
   }
 }
 
-function switchTab (routes) {
+let positionStore = Object.create(null)
+
+export function getTabBarScrollPosition (id) {
+  return positionStore[id]
+}
+
+function saveTabBarScrollPosition (id) {
+  positionStore[id] = {
+    x: window.pageXOffset,
+    y: window.pageYOffset
+  }
+}
+
+function switchTab (routes, to, from) {
+  if (
+    to &&
+        from &&
+        to.meta.isTabBar &&
+        from.meta.isTabBar
+  ) { // tabbar 跳 tabbar
+    saveTabBarScrollPosition(from.params.__id__)
+  }
   // 关闭非 tabBar 页面
   const pages = getCurrentPages()
   for (let i = pages.length - 1; i >= 0; i--) {
@@ -33,11 +54,13 @@ function reLaunch (toName) {
   // 关闭所有页面
   const pages = getCurrentPages(true)
   for (let i = pages.length - 1; i >= 0; i--) {
-    callPageHook(pages[i], 'onUnload')
-    // 重新reLaunch至首页可能会被keepAlive，先手动强制destroy
+    callPageHook(pages[i], 'onUnload')
+    // 重新reLaunch至首页可能会被keepAlive，先手动强制destroy
     pages[i].$destroy()
   }
-  this.keepAliveInclude = []
+  this.keepAliveInclude = []
+  // 清空 positionStore
+  positionStore = Object.create(null)
 }
 
 let currentPages = []
@@ -65,7 +88,7 @@ function beforeEach (to, from, next, routes) {
         removeKeepAliveInclude.call(this, fromName)
         if (from.meta) {
           if (from.meta.isQuit) { // 如果 redirectTo 的前一个页面是 quit 类型，则新打开的页面也是 quit
-            to.meta.isQuit = true
+            to.meta.isQuit = true
             to.meta.isEntry = !!from.meta.isEntry
           }
           if (from.meta.isTabBar) { // 如果是 tabBar，需要更新系统组件 tabBar 内的 list 数据
@@ -78,7 +101,7 @@ function beforeEach (to, from, next, routes) {
 
         break
       case 'switchTab':
-        switchTab.call(this, routes)
+        switchTab.call(this, routes, to, from)
         break
       case 'reLaunch':
         reLaunch.call(this, toName)

src/core/service/plugins/index.js

@@ -16,6 +16,10 @@ import {
   createPageMixin
 } from './page'
 
+import {
+  getTabBarScrollPosition
+} from './app/router-guard'
+
 function getMinId (routes) {
   let minId = 0
   routes.forEach(route => {
@@ -62,6 +66,17 @@ export default {
         if (savedPosition) {
           return savedPosition
         } else {
+          if (
+            to &&
+                        from &&
+                        to.meta.isTabBar &&
+                        from.meta.isTabBar
+          ) { // tabbar 跳 tabbar
+            const position = getTabBarScrollPosition(to.params.__id__)
+            if (position) {
+              return position
+            }
+          }
           return {
             x: 0,
             y: 0
@@ -101,7 +116,9 @@ export default {
           const appMixin = createAppMixin(routes, entryRoute)
           // mixin app hooks
           Object.keys(appMixin).forEach(hook => {
-            options[hook] = options[hook] ? [].concat(appMixin[hook], options[hook]) : [appMixin[hook]]
+            options[hook] = options[hook] ? [].concat(appMixin[hook], options[hook]) : [
+              appMixin[hook]
+            ]
           })
 
           // router
@@ -117,7 +134,9 @@ export default {
           const pageMixin = createPageMixin()
           // mixin page hooks
           Object.keys(pageMixin).forEach(hook => {
-            options[hook] = options[hook] ? [].concat(pageMixin[hook], options[hook]) : [pageMixin[hook]]
+            options[hook] = options[hook] ? [].concat(pageMixin[hook], options[hook]) : [
+              pageMixin[hook]
+            ]
           })
         } else {
           if (this.$parent && this.$parent.__page__) {