视频 p41

页面切换部分

List<Widget> _pages = [ChtPage(),FriendsPage(),DiscoverPage()];

int currentIndex = 0;

final PageConroller _controller = PageController();

Widget build(BuildContext context){

return Scaffold(

body:PageView(

physics:NaverScrollableScrollPhysics(), //禁止左右拖拽

//左右拖拽时，也要改变 当前index

onPageChanged:(int index){

_currentIndex = index;

setState((){});

},

controller:_controller,

children:_pages,

),

bottomNavigationBar:BottomNavigationBar(

onTap:(index){

setState((){

_currentIndex = index;

_controller.jumpToPage(_currentIndex);

})

}

)

);

}

在各页面设置可以保持页面active 的属性

class ChatPage extends StatefulWidget{

_ChatPageState createState()=>_ChatPageState();

}

class _ChatPageState extends State<ChatPage>

with AutomatickeepAliveClientMixin<ChatPage>

{

bool get wantKeepAlive=>true;

Widget build(BuildContext context){

super.build(context);

return Scaffold();

}

}