flutter 环形进度条组件CircularProgressIndicator、线性进度条组件LinearProgressIndicator

环形进度条组件
	不能放在ListView中
	 若不设置value,即无value参数,会一直加载动画
	 
	 LinearProgressIndicator(
        valueColor: AlwaysStoppedAnimation(Colors.x),  设置进度颜色
        backgroundColor: Colors.x,  设置整个进度条颜色
        value:0.9   进度值,0到1之间
      )


线性进度条组件
	若不设置value,即无value参数,会一直加载动画
	
    LinearProgressIndicator(
        valueColor: AlwaysStoppedAnimation(Colors.red), 设置进度颜色
        backgroundColor: Colors.black,  置整个进度条颜色
        value:0.9    进度值,0到1之间
      )

代码示例:

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

class Fx extends StatefulWidget {


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

class _AppsState extends State<Fx> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar:AppBar(
        centerTitle: true,
        title: Text('发现'),
      ),
      body: Home()
    );
  }
}

class Home extends StatefulWidget {
  Home({Key key}) : super(key: key);

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

class _HomeState extends State<Home> {

  ScrollController scroll=new ScrollController();

  Future<void> refresh() async{
    print('上拉刷新');
  }

  @override
  Widget build(BuildContext context) {
    return RefreshIndicator(
      onRefresh: refresh,
      child:  Container(
       child: Column(
        //  controller: scroll,
         children: <Widget>[

        CircularProgressIndicator(
            valueColor: AlwaysStoppedAnimation(Colors.red),
            backgroundColor: Colors.red,
            value: 0.5,
          ) ,

          LinearProgressIndicator(
            valueColor: AlwaysStoppedAnimation(Colors.red),
            backgroundColor: Colors.black,
            value:0.9
          ),

         ],
       ),
    ),
    );

  }
}