1 准备

指纹识别需要用到第三方库 local_auth，地址 https://pub.flutter-io.cn/packages/local_auth
需要有一台支持指纹的安卓手机

2 开始吧

2.1 引入第三方库

pubspec.yaml文件中引入local_auth，如下：

2.2 配置文件中添加配置

android\app\src\main\AndroidManifest.xml文件中添加如下配置：

<uses-permission android:name="android.permission.USE_FINGERPRINT"/>

如下：

2.3 开始编写

lib/pages目录下，新建dart，如下：

local_auth_page.dart 如下：

import 'package:flutter/material.dart';
import 'package:fluttertoast/fluttertoast.dart';
import 'package:local_auth/auth_strings.dart';
import 'package:local_auth/local_auth.dart';
import 'package:flutter_demo/provider/sdf_provider.dart';
import 'package:provider/provider.dart';

class LocalAuthPage extends StatefulWidget {
  LocalAuthPage({Key key}) : super(key: key);

  @override
  _LocalAuthPageState createState() => _LocalAuthPageState();
}

class _LocalAuthPageState extends State<LocalAuthPage> {
  var localAuth = LocalAuthentication();

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          title: Text('指纹识别demo'),
        ),
        body: Container(
          child: Column(
            children: [
              RaisedButton(
                onPressed: () async {
                  try {
                    bool canCheckBiometrics =
                        await localAuth.canCheckBiometrics;
                    print(canCheckBiometrics);
                  } catch (e) {
                    print(3);
                  }
                },
                child: Text('检测是否支持生物识别'),
              ),
              Divider(),
              RaisedButton(
                onPressed: () async {
                  try {
                    List<BiometricType> availableBiometrics =
                        await localAuth.getAvailableBiometrics();
                    print(availableBiometrics);
                  } catch (e) {
                    print(e);
                  }
                },
                child: Text('获取支持的生物识别列表'),
              ),
              Divider(),
              RaisedButton(
                onPressed: () async {
                  //下面是汉化
                  const andStrings = const AndroidAuthMessages(
                    cancelButton: '取消',
                    goToSettingsButton: '去设置',
                    fingerprintNotRecognized: '指纹识别失败',
                    goToSettingsDescription: '请设置指纹.',
                    fingerprintHint: '指纹',
                    fingerprintSuccess: '指纹识别成功',
                    signInTitle: '指纹验证',
                    fingerprintRequiredTitle: '请先录入指纹!',
                  );
                  try {
                    bool didAuthenticate =
                        await localAuth.authenticateWithBiometrics(
                            localizedReason: '扫描指纹进行身份识别',
                            useErrorDialogs: false,
                            stickyAuth: true,
                            androidAuthStrings: andStrings);
                    print('didAuthenticate: $didAuthenticate');
                  } catch (e) {
                    if (e.code == 'NotEnrolled') {
                      Fluttertoast.showToast(
                          msg: '请先设置指纹', backgroundColor: Colors.grey);
                    }
                  }
                },
                child: Text('指纹识别'),
              ),
              Divider(),
              // 是否开启指纹登录
              Row(
                mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                children: [
                  Text('开启指纹登录'),
                  Provider.of<SDFProvider>(context).fingerLoginEnable
                      ? IconButton(
                          onPressed: () async {
                            await Provider.of<SDFProvider>(context,
                                    listen: false)
                                .setFingerLoginEnable(false);
                          },
                          icon: Image.asset('assets/images/switch_on.png'),
                        )
                      : IconButton(
                          onPressed: () async {
                            await Provider.of<SDFProvider>(context,
                                    listen: false)
                                .setFingerLoginEnable(true);
                          },
                          icon: Image.asset('assets/images/switch_off.png')),
                ],
              )
            ],
          ),
        ));
  }
}

页面如下：