Capitalize the first letter of a string - Flutter

Widget build(BuildContext context) {
  return Scaffold(
    appBar: AppBar(title: Text('IntrinsicWidth')),
    body: Center(
      child: IntrinsicWidth(
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: <Widget>[
            RaisedButton(
              onPressed: () {},
              child: Text('Short'),
            ),
            RaisedButton(
              onPressed: () {},
              child: Text('A bit Longer'),
            ),
            RaisedButton(
              onPressed: () {},
              child: Text('The Longest text button'),
            ),
          ],
        ),
      ),
    ),
  );
}

import 'package:flutter/material.dart';

void main() {
  runApp(
    new MaterialApp(
      title: 'Hello World App',
      home: new myApp(),
    )
  );
}

class myApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(
        title: new Text('Hello World App'),
      ),
      body: new Center(
        child: new Text(
          'Hello, world!'
        ),
      ),
    );
  }
}

Color color = new Color(0x12345678);
String colorString = color.toString(); // Color(0x12345678)
String valueString = colorString.split('(0x')[1].split(')')[0]; // kind of hacky..
int value = int.parse(valueString, radix: 16);
Color otherColor = new Color(value);

Widget build(BuildContext context) {
  return Scaffold(
    appBar: AppBar(title: Text('IntrinsicWidth')),
    body: Center(
      child: IntrinsicHeight(
        child: Row(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: <Widget>[
            RaisedButton(
              onPressed: () {},
              child: Text('Short'),
            ),
            RaisedButton(
              onPressed: () {},
              child: Text('A bit Longer'),
            ),
            RaisedButton(
              onPressed: () {},
              child: Text('The Longest text button'),
            ),
          ],
        ),
      ),
    ),
  );
}

String capitalize(String s) {
  if (s == null || s.isEmpty) {
    return s;
  }
  return s.length < 1 ? s.toUpperCase() : s[0].toUpperCase() + s.substring(1);
}

Scaffold(
      appBar: AppBar(),
      body: Align(
        alignment: Alignment.topCenter,
        child: LayoutBuilder(
          builder: (BuildContext context, BoxConstraints constraints) {
            return Container(
              height: constraints.maxHeight / 2,
              width: MediaQuery.of(context).size.width / 2,
              color: Colors.red,
            );
          },
        ),
      ),
    );

TextField(
 enabled: false, // to trigger disabledBorder
 decoration: InputDecoration(
   filled: true,
   fillColor: Color(0xFFF2F2F2),
   focusedBorder: OutlineInputBorder(
     borderRadius: BorderRadius.all(Radius.circular(4)),
     borderSide: BorderSide(width: 1,color: Colors.red),
   ),
   disabledBorder: OutlineInputBorder(
     borderRadius: BorderRadius.all(Radius.circular(4)),
     borderSide: BorderSide(width: 1,color: Colors.orange),
   ),
   enabledBorder: OutlineInputBorder(
     borderRadius: BorderRadius.all(Radius.circular(4)),
     borderSide: BorderSide(width: 1,color: Colors.green),
   ),
   border: OutlineInputBorder(
     borderRadius: BorderRadius.all(Radius.circular(4)),
     borderSide: BorderSide(width: 1,)
   ),
   errorBorder: OutlineInputBorder(
     borderRadius: BorderRadius.all(Radius.circular(4)),
     borderSide: BorderSide(width: 1,color: Colors.black)
   ),
   focusedErrorBorder: OutlineInputBorder(
     borderRadius: BorderRadius.all(Radius.circular(4)),
     borderSide: BorderSide(width: 1,color: Colors.yellowAccent)
   ),
   hintText: "HintText",
   hintStyle: TextStyle(fontSize: 16,color: Color(0xFFB3B1B1)),
   errorText: snapshot.error,
 ),
 controller: _passwordController,
 onChanged: _authenticationFormBloc.onPasswordChanged,
                            obscureText: false,
),

class AppColors {
  static MaterialColor hex(String hex) =>
      AppColors._factoryColor(AppColors._getColorHexFromStr(hex));

  static MaterialColor _factoryColor(int color) {
    return MaterialColor(color, <int, Color>{
      50: Color(color),
      100: Color(color),
      200: Color(color),
      300: Color(color),
      400: Color(color),
      500: Color(color),
      600: Color(color),
      700: Color(color),
      800: Color(color),
      900: Color(color),
    });
  }

  static int _getColorHexFromStr(String colorStr) {
    colorStr = "FF" + colorStr;
    colorStr = colorStr.replaceAll("#", "");
    int val = 0;
    int len = colorStr.length;
    for (int i = 0; i < len; i++) {
      int hexDigit = colorStr.codeUnitAt(i);
      if (hexDigit >= 48 && hexDigit <= 57) {
        val += (hexDigit - 48) * (1 << (4 * (len - 1 - i)));
      } else if (hexDigit >= 65 && hexDigit <= 70) {
        // A..F
        val += (hexDigit - 55) * (1 << (4 * (len - 1 - i)));
      } else if (hexDigit >= 97 && hexDigit <= 102) {
        // a..f
        val += (hexDigit - 87) * (1 << (4 * (len - 1 - i)));
      } else {
        val = 0xFFFFFFFF;
      }
    }
    return val;
  }
}

// Example: In your app
// ...
class MyExample extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Container(
    	height: 100.0,
      	width: 100.0,
      	decoration: BoxDecoration(
    		color: AppColors.hex('#000000'),	
    ),
    );
  }
}

Column( 
  crossAxisAlignment: CrossAxisAlignment.start, children: <Widget>[ Container( child: Text('${payment.name}',textAlign: TextAlign.left,), color: Colors.redAccent, ), ...... )

 decoration: BoxDecoration(
          border: Border(
            top: BorderSide(width: 16.0, color: Colors.lightBlue.shade600),
            bottom: BorderSide(width: 16.0, color: Colors.lightBlue.shade900),
          ),
          color: Colors.white,
        ),

extension StringExtension on String {
    String capitalize() {
      return "${this[0].toUpperCase()}${this.substring(1)}";
    }
}

appBar: AppBar(
        automaticallyImplyLeading: false,
        title: Text(signedIn ? 'Home' : 'Sign In'),
      ),

Container(
      height: 120.0,
      width: 120.0,
      decoration: BoxDecoration(
        image: DecorationImage(
          image: AssetImage(
              'assets/assets/alucard.jpg'),
          fit: BoxFit.fill,
        ),
        shape: BoxShape.circle,
      ),
    )

const color = const Color(0xffb74093); // Second `const` is optional in assignments.