Flutter文字识别插件focused_area_ocr_flutter的使用

focused_area_ocr_flutter 是一个基于OCR技术的文字识别插件，可以从相机聚焦区域中获取文本。该插件依赖于 google_mlkit_text_recognition。

特性

通过这个插件，您可以从相机聚焦区域中提取文本内容。以下是插件的功能展示：

开始使用

iOS 设置

在 ios/Runner/Info.plist 文件中添加以下代码以请求相机和麦克风权限：

<key>NSCameraUsageDescription</key>
<string>your usage description here</string>
<key>NSMicrophoneUsageDescription</key>
<string>your usage description here</string>

编辑 ios/Runner/Info.plist 文件如下：

platform :ios, '12.0'  # 或更新版本

...

# 添加这行:
$iOSVersion = '12.0'  # 或更新版本

post_install do |installer|
  # 添加这些行:
  installer.pods_project.build_configurations.each do |config|
    config.build_settings["EXCLUDED_ARCHS[sdk=*]"] = "armv7"
    config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'] = $iOSVersion
  end
  
  installer.pods_project.targets.each do |target|
    flutter_additional_ios_build_settings(target)
    
    # 添加这些行:
    target.build_configurations.each do |config|
      if Gem::Version.new($iOSVersion) > Gem::Version.new(config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'])
        config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'] = $iOSVersion
      end
    end
    
  end
end

Android 设置

编辑 android/app/build.gradle 并设置以下SDK版本：

• minSdkVersion: 21
• targetSdkVersion: 33
• compileSdkVersion: 33

使用方法

这是一个使用 focused_area_ocr_flutter 插件的Flutter项目的完整示例：

import 'dart:async';
import 'package:flutter/material.dart';
import 'package:focused_area_ocr_flutter/focused_area_ocr_view.dart';

void main() {
  WidgetsFlutterBinding.ensureInitialized();
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  [@override](/user/override)
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Focused Area OCR Flutter',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      home: const MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({Key? key}) : super(key: key);

  [@override](/user/override)
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  final StreamController<String> controller = StreamController<String>();
  final double _textViewHeight = 80.0;

  [@override](/user/override)
  Widget build(BuildContext context) {
    final double statusBarHeight = MediaQuery.of(context).viewPadding.top;
    final Offset focusedAreaCenter = Offset(
      0,
      (statusBarHeight + kToolbarHeight + _textViewHeight) / 2,
    );
    return Scaffold(
      backgroundColor: Colors.black,
      body: Stack(
        children: [
          FocusedAreaOCRView(
            onScanText: (text) {
              controller.add(text);
            },
            focusedAreaCenter: focusedAreaCenter,
          ),
          Column(
            children: [
              SizedBox(
                height: statusBarHeight + kToolbarHeight,
                child: AppBar(
                  title: const Text('Focused Area OCR Flutter'),
                  backgroundColor: Colors.blue,
                  foregroundColor: Colors.white,
                ),
              ),
              Container(
                padding: const EdgeInsets.all(16.0),
                width: double.infinity,
                height: _textViewHeight,
                color: Colors.black,
                child: StreamBuilder<String>(
                  stream: controller.stream,
                  builder: (BuildContext context, AsyncSnapshot<String> snapshot) {
                    return Text(
                      snapshot.data != null ? snapshot.data! : '',
                      style: const TextStyle(color: Colors.white),
                    );
                  },
                ),
              ),
            ],
          ),
        ],
      ),
    );
  }
}