Flutter扩展功能插件flutter_extensions的使用

Flutter Extensions

Widgets

Enums

BuildContext

DateTime - Time

Size

InputDecoration

Table

Listenable - ChangeNotifier

RxStream

监听Stream或StreamValue并过滤先前和当前状态 不重复数据或AsyncSnapshot

示例代码

AspectRatioBuilder

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

class AspectRatioExample extends StatelessWidget {
  [@override](/user/override)
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('AspectRatioBuilder Example')),
      body: Center(
        child: AspectRatioBuilder(
          aspectRatio: 16 / 9,
          builder: (context, size) {
            return Container(
              width: size.width,
              height: size.height,
              color: Colors.blue,
            );
          },
        ),
      ),
    );
  }
}

FixedIndexedStack

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

class FixedIndexedStackExample extends StatelessWidget {
  final int selectedIndex = 0;

  [@override](/user/override)
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('FixedIndexedStack Example')),
      body: Center(
        child: FixedIndexedStack(
          index: selectedIndex,
          children: [
            Container(color: Colors.red, width: 100, height: 100),
            Container(color: Colors.green, width: 100, height: 100),
            Container(color: Colors.blue, width: 100, height: 100),
          ],
        ),
      ),
    );
  }
}

InkStack

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

class InkStackExample extends StatelessWidget {
  [@override](/user/override)
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('InkStack Example')),
      body: Center(
        child: InkStack(
          onTap: () {
            print("Image Tapped");
          },
          child: Image.network(
            'https://example.com/image.png',
            fit: BoxFit.cover,
          ),
        ),
      ),
    );
  }
}

KeyboardRemover

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

class KeyboardRemoverExample extends StatelessWidget {
  [@override](/user/override)
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('KeyboardRemover Example')),
      body: GestureDetector(
        onTap: () {
          FocusScope.of(context).unfocus();
        },
        child: Center(
          child: Text('Tap to remove keyboard'),
        ),
      ),
    );
  }
}

SizeCopier

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

class SizeCopierExample extends StatefulWidget {
  [@override](/user/override)
  _SizeCopierExampleState createState() => _SizeCopierExampleState();
}

class _SizeCopierExampleState extends State<SizeCopierExample> {
  SizeCopierController _controller = SizeCopierController();

  [@override](/user/override)
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('SizeCopier Example')),
      body: Column(
        children: [
          SizeCopier(
            controller: _controller,
            child: Container(
              width: 100,
              height: 100,
              color: Colors.red,
            ),
          ),
          Container(
            width: _controller.size?.width,
            height: _controller.size?.height,
            color: Colors.blue,
          ),
        ],
      ),
    );
  }
}

SizeCopy

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

class SizeCopyExample extends StatelessWidget {
  [@override](/user/override)
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('SizeCopy Example')),
      body: SizeCopy(
        builder: (context, size) {
          return Container(
            width: size.width,
            height: size.height,
            color: Colors.green,
          );
        },
      ),
    );
  }
}

ChangeableBuilder

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

class ChangeableBuilderExample extends StatefulWidget {
  [@override](/user/override)
  _ChangeableBuilderExampleState createState() =>
      _ChangeableBuilderExampleState();
}

class _ChangeableBuilderExampleState extends State<ChangeableBuilderExample>
    with ChangeNotifier {
  int counter = 0;

  void increment() {
    counter++;
    notifyListeners();
  }

  [@override](/user/override)
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('ChangeableBuilder Example')),
      body: ChangeableBuilder<int>(
        listenable: this,
        builder: (context, value) {
          return Center(
            child: Text('Counter: $value'),
          );
        },
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: increment,
        child: Icon(Icons.add),
      ),
    );
  }
}

RxStreamBuilder

import 'package:flutter/material.dart';
import 'package:flutter_extensions/flutter_extensions.dart';
import 'package:rxdart/rxdart.dart';

class RxStreamBuilderExample extends StatelessWidget {
  final Stream<int> _stream = BehaviorSubject<int>.seeded(0);

  [@override](/user/override)
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('RxStreamBuilder Example')),
      body: Center(
        child: RxStreamBuilder<int>(
          stream: _stream,
          builder: (context, snapshot) {
            if (snapshot.hasData) {
              return Text('Current Value: ${snapshot.data}');
            } else {
              return Text('Loading...');
            }
          },
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: () {
          _stream.sink.add(_stream.value + 1);
        },
        child: Icon(Icons.add),
      ),
    );
  }
}