New Calculator

 

import 'package:flutter/material.dart';

class HomePage extends StatefulWidget {
  @override
  _HomePageState createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {

  var num1=0,num2=0,sum=0,numclear = 0;

  final TextEditingController t1 = new TextEditingController(text: "0");
  final TextEditingController t2 = new TextEditingController(text: "0");

  void doAddition(){
    setState(() {
      num1 = int.parse(t1.text);
      num2 = int.parse(t2.text);
      sum  = num1+num2;
    });
  }
  void doSubtraction(){
    setState(() {
      num1 = int.parse(t1.text);
      num2 = int.parse(t2.text);
      sum  = num1-num2;
    });
  }
  void doMultiplication(){
    setState(() {
      num1 = int.parse(t1.text);
      num2 = int.parse(t2.text);
      sum  = num1*num2;
    });
  }
  void doDivision(){
    setState(() {
      num1 = int.parse(t1.text);
      num2 = int.parse(t2.text);
      sum  = num1~/num2;
    });
  }

  void doClear(){
    setState(() {
      t1.text ="0";
      t2.text ="0";
      sum = numclear;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Colors.red,
        title: Text("Calculator"),
      ),
      body: new Container(
        padding: EdgeInsets.all(40.0),
        child: new Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget> [
            new Text("Output : $sum",style: TextStyle(fontSize: 30,
                color: Colors.purpleAccent,fontWeight: FontWeight.bold),),
            new TextField(
              keyboardType: TextInputType.number,
              decoration: InputDecoration(hintText: "Enter Number 1"),
              controller: t1,
            ),
            new TextField(
              keyboardType: TextInputType.number,
              decoration: InputDecoration(hintText: "Enter Number 2"),
              controller: t2,
            ),
            new Padding(
              padding: EdgeInsets.only(top: 20),
            ),
            Row(
              mainAxisAlignment: MainAxisAlignment.spaceEvenly,
              children: [
                new MaterialButton(
                  child: Text("+",style: TextStyle(fontSize: 20),),
                  onPressed: doAddition,
                  color: Colors.greenAccent,
                ),new MaterialButton(
                  child: Text("-",style: TextStyle(fontSize: 30),),
                  onPressed: doSubtraction,
                  color: Colors.greenAccent,
                ),
              ],
            ),
            Row(
              mainAxisAlignment: MainAxisAlignment.spaceEvenly,
              children: [
                new MaterialButton(
                  child: Text("X",style: TextStyle(fontSize: 20),),
                  onPressed: doMultiplication,
                  color: Colors.greenAccent,
                ),new MaterialButton(
                  child: Text("/",style: TextStyle(fontSize: 20),),
                  onPressed: doDivision,
                  color: Colors.greenAccent,
                ),
              ],
            ),
            new Padding(
              padding: EdgeInsets.only(top: 40),
            ),
            new Row(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                new MaterialButton(
                  onPressed: doClear,
                  child: Icon(Icons.refresh),
                  color: Colors.greenAccent,
                )
              ],
            )
          ],
        )
      ),
    );
  }
}