Flutter切换tab后保留tab状态 概述 Flutter中为了节约内存不会保存widget的状态,widget都是临时变量。当我们使用TabBar,TabBarView是我们就会发现,切换tab，initState又会被调用一次。
怎么为了让tab一直保存在内存中，不被销毁？
添加AutomaticKeepAliveClientMixin，并设置为true,这样就能一直保持当前不被initState了。
class TicketListViewState extendsState with AutomaticKeepAliveClientMixin{
@override
void initState(){
super.initState();
}
@override
Widget build(BuildContext context){
super.build(context);
return new SmartRefresher(
enablePullDown:true,
enablePullUp:true,
onRefresh: _onRefresh,
controller: refreshController,
child: ListView.builder(
itemCount: _result.length,
itemBuilder: (context, index) {returngetItem(_result[index]); }, ));
}
//不会被销毁,占内存中@overridebool get wantKeepAlive =>true;
}
如果不起作用
@override Widget build(BuildContext context){
super.build(context);//必须添加..... ));
官方解释
///A mixin with convenience methodsforclients of [AutomaticKeepAlive]. Used///with [State] subclasses.//////Subclasses must implement [wantKeepAlive],andtheir [build] methods must///call`super.build`(thereturnvalue will alwaysreturnnull,andshould be///ignored).