Flutter性能优化插件velocore的使用

velocore 是一个包含可重用小部件和实用工具的集合。通过将其添加到项目中，您可以轻松实现一些常见的功能优化。

在项目中添加 velocore

首先，将以下内容添加到您的 pubspec.yaml 文件中：

dependencies:
  velocore: 0.0.2

然后运行 flutter pub get 来安装依赖。

使用示例

1. ScrollKeyboardCloser

ScrollKeyboardCloser 可以在滚动时自动隐藏键盘。

示例代码：

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

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  [@override](/user/override)
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: Text('ScrollKeyboardCloser 示例')),
        body: ScrollKeyboardCloser(
          child: TextField(
            decoration: InputDecoration(hintText: '输入文字'),
          ),
        ),
      ),
    );
  }
}

2. ScrollableColumn

ScrollableColumn 允许在滚动视图中使用 Expanded 和 Spacer。

示例代码：

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

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  [@override](/user/override)
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: Text('ScrollableColumn 示例')),
        body: ScrollableColumn(
          children: [
            Header(),
            Expanded(
              child: ContentWidget(),
            ),
            BottomButton(), // 如果内容可以完全显示，则按钮会位于屏幕底部；否则，它会位于滚动内容的末尾
          ],
        ),
      ),
    );
  }
}

class Header extends StatelessWidget {
  [@override](/user/override)
  Widget build(BuildContext context) {
    return Container(
      height: 100,
      color: Colors.blue,
      alignment: Alignment.center,
      child: Text('头部', style: TextStyle(color: Colors.white)),
    );
  }
}

class ContentWidget extends StatelessWidget {
  [@override](/user/override)
  Widget build(BuildContext context) {
    return ListView.builder(
      itemCount: 50,
      itemBuilder: (context, index) {
        return ListTile(title: Text('条目 $index'));
      },
    );
  }
}

class BottomButton extends StatelessWidget {
  [@override](/user/override)
  Widget build(BuildContext context) {
    return Container(
      height: 50,
      color: Colors.green,
      alignment: Alignment.center,
      child: Text('底部按钮', style: TextStyle(color: Colors.white)),
    );
  }
}

3. CustomSlopeTapDetector

CustomSlopeTapDetector 是一个带有自定义触摸斜率的点击检测器。

示例代码：

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

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  void _onTap() {
    print('按钮被点击');
  }

  [@override](/user/override)
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: Text('CustomSlopeTapDetector 示例')),
        body: Center(
          child: CustomSlopeTapDetector(
            onTap: _onTap,
            factor: 2, // 将默认触摸斜率乘以 2
            child: Container(
              width: 200,
              height: 100,
              color: Colors.red,
              alignment: Alignment.center,
              child: Text(
                '点击我',
                style: TextStyle(fontSize: 20, color: Colors.white),
              ),
            ),
          ),
        ),
      ),
    );
  }
}

4. MeasureSize

MeasureSize 可以监听子部件大小的变化。

示例代码：

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

void main() {
  runApp(MyApp());
}

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

class _MyAppState extends State<MyApp> {
  Size? _size;

  [@override](/user/override)
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: Text('MeasureSize 示例')),
        body: MeasureSize(
          onChange: (size) {
            setState(() {
              _size = size;
            });
          },
          child: Container(
            width: 200,
            height: 200,
            color: Colors.blue,
            child: Center(child: Text('大小变化时更新')),
          ),
        ),
        floatingActionButton: FloatingActionButton(
          onPressed: () {},
          tooltip: '刷新',
          child: Icon(Icons.refresh),
        ),
      ),
    );
  }
}