【FLUTTER ANDROID STUDIO and IOS】wave slider

 import 'package:flutter/material.dart';

import 'package:wave_slider/wave_slider.dart';
void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        // This is the theme of your application.
        //
        // Try running your application with "flutter run". You'll see the
        // application has a blue toolbar. Then, without quitting the app, try
        // changing the primarySwatch below to Colors.green and then invoke
        // "hot reload" (press "r" in the console where you ran "flutter run",
        // or simply save your changes to "hot reload" in a Flutter IDE).
        // Notice that the counter didn't reset back to zero; the application
        // is not restarted.
        primarySwatch: Colors.blue,
        // This makes the visual density adapt to the platform that you run
        // the app on. For desktop platforms, the controls will be smaller and
        // closer together (more dense) than on mobile platforms.
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      home: SliderDemo(),
    );
  }
}
class SliderDemo extends StatefulWidget {
  @override
  _SliderDemoState createState() => _SliderDemoState();
}

class _SliderDemoState extends State<SliderDemo> {
  double _dragValue = 0;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.brown[50],
      appBar: AppBar(
        title: Text("Flutter Wave Slider Demo"),
        automaticallyImplyLeading: false,
      ),
      body: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: <Widget>[
          WaveSlider(
            color: Colors.teal,
            sliderHeight: 70,
            displayTrackball: true,
            onChanged: (double dragUpdate) {
              setState(() {
                _dragValue = dragUpdate * 150;
              });
            },
          ),
          Padding(
            padding: const EdgeInsets.all(8.0),
            child: Text(
              'Drag Value',
              style: TextStyle(fontSize: 20,
                  fontWeight: FontWeight.bold,
                  color: Colors.black),
            ),
          ),
          Padding(
            padding: const EdgeInsets.all(8.0),
            child: Text(
              '$_dragValue',
              style: TextStyle(fontSize: 16,
                color: Colors.red,),
            ),
          )
        ],
      ),
    );
  }
}