arkts整改

Signed-off-by: Nswx1239486 <songqinqin4@huawei.com>

zh-cn/application-dev/key-features/multi-device-app-dev/responsive-layout.md

@@ -230,10 +230,16 @@ export class BreakpointSystem {
   }
 
   public unregister() :void{
+    if(smListener){
       this.smListener.off("change", this.isBreakpointSM)
+    }
+    if(mdListener){
       this.mdListener.off("change", this.isBreakpointMD)
+    }
+    if(lgListener){
       this.lgListener.off("change", this.isBreakpointLG)
     }
+  }
 }
 
 ```

zh-cn/application-dev/key-features/multi-device-app-dev/settings-application-page.md

@@ -60,6 +60,12 @@ struct Index {
 ```
 ```typescript
 //核心代码 SettingList.ets
+import { MainItem } from '../components/MainItem'
+import { ItemGroup } from '../components/ItemGroup'
+import { SearchBox } from '../components/SearchBox'
+import { MoreConnectionsItem } from '../moreconnections/MoreConnectionsItem'
+import { WlanSettingItem } from '../wlan/WlanSettingItem'
+        
 class  ItemObj {
   title?: Resource
   tag?: string
@@ -115,12 +121,6 @@ let aboutTab:ItemObj={
   icon: $r('app.media.aboutDevice'),
 }
         
-import { MainItem } from '../components/MainItem'
-import { ItemGroup } from '../components/ItemGroup'
-import { SearchBox } from '../components/SearchBox'
-import { MoreConnectionsItem } from '../moreconnections/MoreConnectionsItem'
-import { WlanSettingItem } from '../wlan/WlanSettingItem'
-
 @Component
 export struct SettingList {
   @Builder