Flutter文档扫描插件flutter_twain_scanner的使用

Flutter文档扫描插件flutter_twain_scanner的使用

插件简介

flutter_twain_scanner 是一个Flutter插件，用于开发跨平台应用程序，可以从TWAIN (32-bit/64-bit)、WIA、SANE、ICA和eSCL扫描仪中数字化文档。该插件提供了可调用的方法，支持开源TWAIN（仅限64位）和Dynamsoft Service REST API。

Dynamsoft Service REST API

默认情况下，REST API的主机地址设置为 http://127.0.0.1:18622。以下是API的主要方法：

安装Dynamsoft Service

要使Dynamsoft Service正常工作，请按照以下步骤操作：

1. 安装Dynamsoft Service：

   • Windows: 安装 Dynamsoft-Service-Setup.msi
   • macOS: 安装 Dynamsoft-Service-Setup.pkg
   • Linux:
     • 安装 Dynamsoft-Service-Setup.deb
     • 安装 Dynamsoft-Service-Setup-arm64.deb
     • 安装 Dynamsoft-Service-Setup-mips64el.deb
     • 安装 Dynamsoft-Service-Setup.rpm

2. 申请免费试用许可证：

   • 访问 Dynamsoft官网 申请免费试用许可证。

Dynamsoft Service配置

安装Dynamsoft Service后，可以通过浏览器访问 http://127.0.0.1:18625/ 来配置主机和端口设置。默认主机IP地址为 127.0.0.1。如果希望在办公室内从桌面、移动和Web应用程序访问服务，可以将主机设置更新为局域网IP地址，例如 192.168.8.72。

API使用

Open Source TWAIN (Windows 64-bit only)

• 获取TWAIN兼容扫描仪列表：

  List<String> scanners = await _flutterTwainScannerPlugin.getDataSources();
  

• 从选定扫描仪扫描文档：

  int index = _scanners.indexOf(_selectedScanner!);
  List<String> documentPaths = await _flutterTwainScannerPlugin.scanDocument(index);
  

Dynamsoft Service (Windows, macOS, Linux, Android, iOS and Web)

• 获取TWAIN、WIA和eSCL兼容扫描仪列表：

  final DynamsoftService dynamsoftService = DynamsoftService();
  String host = 'http://127.0.0.1:18622';
  final scanners = await dynamsoftService.getDevices(host, ScannerType.TWAINSCANNER | ScannerType.TWAINX64SCANNER);
  

• 删除扫描任务：

  await dynamsoftService.deleteJob(host, jobId);
  

• 保存扫描任务中的图像到目录：

  List<Uint8List> paths = await dynamsoftService.getImageFiles(host, jobId, './');
  

• 从扫描任务中获取图像流：

  List<Uint8List> paths = await dynamsoftService.getImageStreams(host, jobId);
  

• 创建新的扫描任务：

  final Map<String, dynamic> parameters = {
    'license': 'LICENSE-KEY',
    'device': devices[index]['device'],
  };
  
  parameters['config'] = {
    'IfShowUI': false,
    'PixelType': 2,
    'Resolution': 200,
    'IfFeederEnabled': false,
    'IfDuplexEnabled': false,
  };
  
  final String jobId = await dynamsoftService.scanDocument(host, parameters);
  

完整示例Demo

import 'package:flutter/material.dart';
import 'dart:async';
import 'package:flutter/services.dart';
import 'package:flutter_twain_scanner/flutter_twain_scanner.dart';
import 'package:flutter_twain_scanner/dynamsoft_service.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> {
  final _flutterTwainScannerPlugin = FlutterTwainScanner();
  List<String> scannerNames = [];
  String? _selectedScanner;
  String host = 'http://192.168.8.72:18622'; // 替换为您的局域网IP地址
  final DynamsoftService dynamsoftService = DynamsoftService();
  List<dynamic> devices = [];
  List<Uint8List> imagePaths = [];

  [@override](/user/override)
  void initState() {
    super.initState();
    initPlatformState();
  }

  // 平台消息是异步的，因此我们在异步方法中初始化
  Future<void> initPlatformState() async {
    if (!mounted) return;
  }

  Future<void> _scanDocument(int index) async {
    final Map<String, dynamic> parameters = {
      'license': 'LICENSE-KEY', // 替换为您的许可证密钥
      'device': devices[index]['device'],
    };

    parameters['config'] = {
      'IfShowUI': false,
      'PixelType': 2, // 0: 黑白, 1: 灰度, 2: 彩色
      'Resolution': 200, // 分辨率
      'IfFeederEnabled': false, // 是否启用进纸器
      'IfDuplexEnabled': false, // 是否启用双面扫描
    };

    try {
      final String jobId = await dynamsoftService.scanDocument(host, parameters);

      if (jobId != '') {
        List<Uint8List> paths = await dynamsoftService.getImageStreams(host, jobId);

        await dynamsoftService.deleteJob(host, jobId);

        if (paths.isNotEmpty) {
          setState(() {
            imagePaths.insertAll(0, paths);
          });
        }
      }
    } catch (error) {
      print('An error occurred: $error');
    }
  }

  [@override](/user/override)
  Widget build(BuildContext context) {
    Row row = Row(
      mainAxisAlignment: MainAxisAlignment.spaceEvenly,
      children: <Widget>[
        MaterialButton(
          textColor: Colors.white,
          color: Colors.blue,
          onPressed: () async {
            try {
              final scanners = await dynamsoftService.getDevices(host,
                  ScannerType.TWAINSCANNER | ScannerType.TWAINX64SCANNER);
              for (var i = 0; i < scanners.length; i++) {
                devices.add(scanners[i]);
                scannerNames.add(scanners[i]['name']);
              }
              if (devices.isNotEmpty) {
                setState(() {
                  _selectedScanner = devices[0]['name'];
                });
              }
            } catch (error) {
              print('An error occurred: $error');
            }
          },
          child: const Text('List Scanners'),
        ),
        MaterialButton(
          textColor: Colors.white,
          color: Colors.blue,
          onPressed: () async {
            if (_selectedScanner != null) {
              int index = scannerNames.indexOf(_selectedScanner!);
              await _scanDocument(index);
            }
          },
          child: const Text('Scan Document'),
        ),
      ],
    );

    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Flutter TWAIN Scanner'),
        ),
        body: Column(
          mainAxisAlignment: MainAxisAlignment.start,
          children: [
            SizedBox(
              height: 100,
              child: row,
            ),
            DropdownButton(
              hint: const Text('Select a scanner'), // 选项1不需要
              value: _selectedScanner,
              onChanged: (newValue) {
                setState(() {
                  _selectedScanner = newValue;
                });
              },
              items: scannerNames.map((location) {
                return DropdownMenuItem(
                  value: location,
                  child: Text(location),
                );
              }).toList(),
            ),
            Expanded(
              child: imagePaths.isEmpty
                  ? Image.asset('images/default.png')
                  : ListView.builder(
                      itemCount: imagePaths.length,
                      itemBuilder: (context, index) {
                        return Padding(
                          padding: const EdgeInsets.all(10.0),
                          child: Image.memory(
                            imagePaths[index],
                            fit: BoxFit.contain,
                          ), // 对于本地图像，使用 Image.file()
                        );
                      },
                    ),
            ),
          ],
        ),
      ),
    );
  }
}