chatting/lib/loading_page.dart

import 'package:flutter/material.dart';
import 'package:shared_preferences/shared_preferences.dart';

/**
 * 首页 加载页
 */
class LoadingPage extends StatefulWidget {
  @override
  _LoadingPageState createState() => _LoadingPageState();
}

class _LoadingPageState extends State<LoadingPage> {

  //0 未登录 ,1 已登录
  void initData() async {
    final prefs = await SharedPreferences.getInstance(); //获取SP的实例
    int loginStatus=prefs.getInt('loginStatus') ?? 0;
    print(prefs.getInt('current_num'));
    if(loginStatus == 1){
      Navigator.of(context).pushReplacementNamed("login");
    }else{
      loginStatus=1;
      Navigator.of(context).pushReplacementNamed("app");
    }
  }

  @override
  void initState() {
    super.initState();
    //加载页默认停留三秒
    Future.delayed(Duration(seconds: 3),(){
      print("仿微信app页面正在加载中");
      //判断是否登录,如果没有登陆则跳转至登录页,如果登录则跳转至聊天页
      initData();
    });
  }

  @override
  Widget build(BuildContext context) {
    return new Center(
      child: Stack(
        children: <Widget>[
        //加载页面居中背景图使用 cover 模式
        Image. asset("assets/images/loading.jpg", fit: BoxFit.cover,),
        ],
      ),
    );
  }
}