Flutter字体管理插件flutter_overpass的使用
Flutter Overpass Plugin
Flutter Overpass Plugin 是一个用于从 Overpass API 和 Nominatim 获取数据的插件，支持 Android 和 iOS 平台。本文将介绍如何使用这个插件。
Features
- ✅ 根据坐标和半径获取附近的地点。
- ✅ 使用原始的 Overpass QL 语句来获取结果。
- ✅ 根据给定的坐标获取地点。
- ✅ 通过地址搜索。
How to Use
首先，确保在 pubspec.yaml 文件中添加 flutter_overpass 插件：
dependencies:
flutter:
sdk: flutter
flutter_overpass: ^0.1.0 # 确保使用最新版本
然后运行 flutter pub get 来安装插件。
示例代码
以下是一个完整的示例应用，展示如何使用 flutter_overpass 插件进行各种查询操作：
import 'package:flutter/material.dart';
import 'dart:async';
import 'package:flutter_overpass/flutter_overpass.dart';
void main() {
runApp(const MyApp());
}
class MyApp extends StatefulWidget {
const MyApp({super.key});
[@override](/user/override)
State<MyApp> createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
String _platformVersion = 'Unknown';
final _flutterOverpassPlugin = FlutterOverpass();
final _isLoading = ValueNotifier<bool>(false);
final _controllerLatitude = TextEditingController(text: '37.79396544487583');
final _controllerLongitude = TextEditingController(text: '-122.3838801383972');
final _controllerRadius = TextEditingController(text: '200');
final _controllerAddress = TextEditingController(text: 'Rihanna Drive');
final _controllerQuery = TextEditingController(
text: 'node(around:200,37.79396544487583,-122.3838801383972);');
String _results = '';
[@override](/user/override)
void initState() {
super.initState();
initPlatformState();
}
[@override](/user/override)
void dispose() {
_isLoading.dispose();
_controllerLatitude.dispose();
_controllerLongitude.dispose();
_controllerRadius.dispose();
_controllerAddress.dispose();
_controllerQuery.dispose();
super.dispose();
}
Future<void> initPlatformState() async {
String platformVersion;
try {
platformVersion = await _flutterOverpassPlugin.getPlatformVersion() ??
'Unknown platform version';
} on PlatformException {
platformVersion = 'Failed to get platform version.';
}
if (!mounted) return;
setState(() {
_platformVersion = platformVersion;
});
}
[@override](/user/override)
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
appBar: AppBar(
title: const Text('Flutter Overpass'),
),
body: Stack(
children: [
Padding(
padding: const EdgeInsets.symmetric(horizontal: 16),
child: Column(
children: [
const Text(
'Results:',
style: TextStyle(fontWeight: FontWeight.bold, fontSize: 18),
),
Container(
height: 100,
padding: const EdgeInsets.all(4),
decoration: BoxDecoration(border: Border.all(color: Colors.grey)),
child: SingleChildScrollView(child: Center(child: Text(_results))),
),
Expanded(
child: ListView(
children: [
Center(child: Text('Running on: $_platformVersion\n')),
TextFormField(
decoration: const InputDecoration(labelText: 'Latitude'),
controller: _controllerLatitude,
keyboardType: const TextInputType.numberWithOptions(decimal: true),
),
TextFormField(
decoration: const InputDecoration(labelText: 'Longitude'),
controller: _controllerLongitude,
keyboardType: const TextInputType.numberWithOptions(decimal: true),
),
TextFormField(
decoration: const InputDecoration(labelText: 'Radius'),
controller: _controllerRadius,
keyboardType: const TextInputType.numberWithOptions(decimal: true),
),
TextFormField(
decoration: const InputDecoration(labelText: 'Address'),
controller: _controllerAddress,
),
const SizedBox(height: 8),
Center(
child: TextButton(
onPressed: () async {
if (_controllerLongitude.text.isEmpty ||
_controllerLatitude.text.isEmpty ||
_controllerRadius.text.isEmpty) return;
_isLoading.value = true;
setState(() {
_results = '';
});
final result = await _flutterOverpassPlugin.getNearbyNodes(
latitude: double.parse(_controllerLatitude.text),
longitude: double.parse(_controllerLongitude.text),
radius: double.parse(_controllerRadius.text),
);
setState(() {
_results = result.toString();
});
_isLoading.value = false;
},
child: const Text('Get Nearby Nodes'),
),
),
Center(
child: TextButton(
onPressed: () async {
if (_controllerLongitude.text.isEmpty ||
_controllerLatitude.text.isEmpty) return;
_isLoading.value = true;
setState(() {
_results = '';
});
final result = await _flutterOverpassPlugin
.getPlaceFromCoordinate(
latitude: double.parse(_controllerLatitude.text),
longitude: double.parse(_controllerLongitude.text),
);
setState(() {
_results = result.toString();
});
_isLoading.value = false;
},
child: const Text('Get Place From Coordinate'),
),
),
Center(
child: TextButton(
onPressed: () async {
if (_controllerAddress.text.isEmpty) return;
_isLoading.value = true;
setState(() {
_results = '';
});
final result = await _flutterOverpassPlugin.searchAddress(
address: _controllerAddress.text,
);
setState(() {
_results =
result.map((e) => e.toString()).join('\n');
});
_isLoading.value = false;
},
child: const Text('Search Address'),
),
),
const SizedBox(height: 44),
TextFormField(
decoration: const InputDecoration(labelText: 'Overpass Query'),
controller: _controllerQuery,
),
Center(
child: TextButton(
onPressed: () async {
_isLoading.value = true;
setState(() {
_results = '';
});
final result = await _flutterOverpassPlugin.rawOverpassQL(
query: _controllerQuery.text,
);
setState(() {
_results = result.toString();
});
_isLoading.value = false;
},
child: const Text('Run query'),
),
),
],
),
),
],
),
),
ValueListenableBuilder(
valueListenable: _isLoading,
builder: (BuildContext context, bool value, Widget? child) {
return value
? Container(
color: Colors.black.withOpacity(0.5),
width: double.infinity,
height: double.infinity,
child: const Center(child: CircularProgressIndicator()),
)
: const SizedBox();
},
),
],
),
),
);
}
}
更多关于Flutter字体管理插件flutter_overpass的使用的实战系列教程也可以访问 https://www.itying.com/category-92-b0.html
1 回复
更多关于Flutter字体管理插件flutter_overpass的使用的实战系列教程也可以访问 https://www.itying.com/category-92-b0.html
当然，下面是一个关于如何在Flutter项目中使用flutter_overpass插件进行字体管理的代码示例。flutter_overpass是一个Flutter插件，用于轻松集成Overpass字体到你的应用中。假设你已经将flutter_overpass添加到了你的pubspec.yaml文件中，以下是具体的使用步骤：
1. 添加依赖
首先，确保你的pubspec.yaml文件中已经添加了flutter_overpass依赖：
dependencies:
flutter:
sdk: flutter
flutter_overpass: ^最新版本号 # 请替换为最新的版本号
然后运行flutter pub get来获取依赖。
2. 导入插件
在你的Dart文件中导入flutter_overpass：
import 'package:flutter_overpass/flutter_overpass.dart';
3. 使用Overpass字体
3.1 初始化插件
在你的应用入口（通常是main.dart）中初始化flutter_overpass插件：
void main() {
runApp(MyApp());
// 初始化Overpass字体（通常在应用启动时调用一次）
OverpassFont.load();
}
3.2 应用全局字体样式
你可以通过OverpassTextTheme和OverpassTextStyle来自定义和应用Overpass字体样式。以下是一个完整的示例，展示如何在整个应用中应用Overpass字体：
import 'package:flutter/material.dart';
import 'package:flutter_overpass/flutter_overpass.dart';
void main() {
runApp(MyApp());
// 初始化Overpass字体
OverpassFont.load();
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Overpass Demo',
theme: ThemeData(
// 使用OverpassTextTheme来设置全局文本主题
textTheme: OverpassTextTheme.light(),
// 或者你可以自定义OverpassTextStyle
// primaryTextTheme: TextTheme(
// headline1: OverpassTextStyle.headline1(color: Colors.black),
// bodyText1: OverpassTextStyle.bodyText1(color: Colors.grey),
// // ... 其他文本样式
// ),
),
home: MyHomePage(),
);
}
}
class MyHomePage extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Overpass Font Demo'),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text(
'Hello, Overpass!',
style: OverpassTextStyle.headline1, // 使用OverpassTextStyle
),
SizedBox(height: 20),
Text(
'This is a sample text using Overpass font.',
style: OverpassTextStyle.bodyText1, // 使用OverpassTextStyle
),
],
),
),
);
}
}
在这个示例中，我们首先初始化了OverpassFont，然后在ThemeData中使用了OverpassTextTheme来设置全局文本主题。你也可以选择自定义OverpassTextStyle来更精细地控制不同文本组件的样式。
4. 运行应用
现在，你可以运行你的Flutter应用，应该会看到所有文本都使用了Overpass字体。
这个示例展示了如何在Flutter项目中集成和使用flutter_overpass插件进行字体管理。如果你有更具体的需求，比如动态加载字体或者处理不同权重和样式的字体，你可以参考flutter_overpass的官方文档或源代码以获取更多信息。
