为什么 flutter 中的小部件在 Tab 上不起作用？

Question

**When I click a widget the screen not changing until I save file again.

this is the log when I click a widget: D/skia ( 5395): Errors: D/skia ( 5395): link failed but did not provide an info log D/skia ( 5395): Shader compilation error D/skia ( 5395): ------------------------ D/skia ( 5395): Errors: D/skia ( 5395): link failed but did not provide an info log**

this is the code

import 'package:flutter/material.dart';
import 'package:flutter_cubit/pages/navpages/bar_item_page.dart';
import 'package:flutter_cubit/pages/navpages/home_page.dart';
import 'package:flutter_cubit/pages/navpages/my_page.dart';
import 'package:flutter_cubit/pages/navpages/search_page.dart';

class MainPage extends StatefulWidget {
  const MainPage({Key? key}) : super(key: key);

  @override
  _MainPageState createState() => _MainPageState();
}

class _MainPageState extends State<MainPage> {
  List pages=[
    HomePage(),
    BarItemPage(),
    SearchPage(),
    MyPage()
  ];
  int currentIndex=0;
  void onTap(int index){
    currentIndex=index;
  }
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: pages[currentIndex],
      bottomNavigationBar: BottomNavigationBar(
        unselectedFontSize: 0,
        selectedFontSize: 0,
        type: BottomNavigationBarType.fixed,
        backgroundColor: Colors.white,
        onTap: onTap,
        currentIndex: currentIndex,
        selectedItemColor: Colors.black54,
        unselectedItemColor: Colors.grey.withOpacity(0.5),
        showUnselectedLabels: false,
        showSelectedLabels: false,
        elevation: 0,

        items: [
          BottomNavigationBarItem(title: Text("Home"), icon: Icon(Icons.apps)),
          BottomNavigationBarItem(title: Text("Bar"), icon: Icon(Icons.bar_chart_sharp)),
          BottomNavigationBarItem(title: Text("Search"), icon: Icon(Icons.search)),
          BottomNavigationBarItem(title: Text("My"), icon: Icon(Icons.person)),
        ],
      ),
    );
  }
}

Answer 1

you are not calling setState. so change onTap to below code:

void onTap(int index){
  setState(() {
    currentIndex=index;
  }); 
}