错误：使用生物特征验证时出错：PlatformException（no_fragment_activity，local_auth 插件要求活动是 FragmentActivity。，null，null）

Question

我正在尝试在 y flutter 应用程序中添加指纹访问权限，但我无法做到，因为我收到以下错误：

error using biometric auth: PlatformException(no_fragment_activity, local_auth plugin requires activity to be a FragmentActivity., null, null)

以下是我的代码：

main.dart：

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

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

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  bool isAuth = false;
  void checkBiometric() async {
    final LocalAuthentication auth = LocalAuthentication();
    bool canCheckBiometrics = false;
    try {
      canCheckBiometrics = await auth.canCheckBiometrics;
    } catch (e) {
      print("error biome trics $e");
    }
    print("biometric is available: $canCheckBiometrics");
    List<BiometricType> availableBiometrics;
    try {
      availableBiometrics = await auth.getAvailableBiometrics();
    } catch (e) {
      print("error enumerate biometrics $e");
    }
    print("following biometrics are available");
    if (availableBiometrics.isNotEmpty) {
      availableBiometrics.forEach((ab) {
        print("\ttech: $ab");
      });
    } else {
      print("no biometrics are available");
    }

    bool authenticated = false;

    try {
      authenticated = await auth.authenticateWithBiometrics(
          localizedReason: 'Touch your finger on the sensor to login',
          useErrorDialogs: true,
          stickyAuth: false
        // androidAuthStrings:AndroidAuthMessages(signInTitle: "Login to HomePage")
      );
    } catch (e) {
      print("error using biometric auth: $e");
    }

    setState(() {
      isAuth = authenticated ? true : false;
    });

    print("authenticated: $authenticated");
  }

  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
        debugShowCheckedModeBanner: false,
        home: new Scaffold(
          appBar: new AppBar(
            title: new Text('BioAuthentication'),
          ),
          body: new Column(
            crossAxisAlignment: CrossAxisAlignment.center,
            children: <Widget>[
              Expanded(
                child: Container(),
              ),
              new RaisedButton(
                splashColor: Colors.pinkAccent,
                color: Colors.black,
                child: new Text(
                  "Authentiate",
                  style: new TextStyle(fontSize: 20.0, color: Colors.white),
                ),
                onPressed: checkBiometric,
              ),
              new Expanded(
                child: Container(),
              ),
              isAuth == true
                  ? Text(
                "Authenticated",
                softWrap: true,
                style: new TextStyle(fontSize: 30.0, color: Colors.black),
              )
                  : Text(
                "Not Authenticated",
                softWrap: true,
                style: new TextStyle(fontSize: 30.0, color: Colors.black),
              ),
              new Expanded(
                child: Container(),
              ),
            ],
          ),
        ));
  }
}

MainActivity.kt：

package com.open.flutter_fingerprint_new

import androidx.annotation.NonNull;
import io.flutter.embedding.android.FlutterFragmentActivity
import io.flutter.embedding.engine.FlutterEngine
import io.flutter.plugins.GeneratedPluginRegistrant

class MainActivity: FlutterFragmentActivity() {
    override fun configureFlutterEngine(@NonNull flutterEngine: FlutterEngine) {
        GeneratedPluginRegistrant.registerWith(flutterEngine);
    }
}

有人可以帮我吗？

注意：除了使用按钮之外，还有什么选项可以在屏幕启动时提示用户输入指纹？

Answer 1

您应该仔细检查 Android 集成和 ios 集成。https://github.com/flutter/plugins/tree/master/packages/local_auth#android-integration

Android 集成

请注意，local_auth 插件需要使用 FragmentActivity 而不是 Activity。 这可以通过在清单中切换到使用 FlutterFragmentActivity 而不是 FlutterActivity 来轻松完成（如果您正在扩展基类，则可以使用您自己的 Activity class）。

import android.os.Bundle;
import io.flutter.app.FlutterFragmentActivity;
import io.flutter.plugins.flutter_plugin_android_lifecycle.FlutterAndroidLifecyclePlugin;
import io.flutter.plugins.localauth.LocalAuthPlugin;

public class MainActivity extends FlutterFragmentActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        FlutterAndroidLifecyclePlugin.registerWith(
                registrarFor(
                        "io.flutter.plugins.flutter_plugin_android_lifecycle.FlutterAndroidLifecyclePlugin"));
        LocalAuthPlugin.registerWith(registrarFor("io.flutter.plugins.localauth.LocalAuthPlugin"));
    }
}

或更新您的 MainActivity.kt：

import io.flutter.embedding.android.FlutterFragmentActivity
import io.flutter.embedding.engine.FlutterEngine
import io.flutter.plugins.GeneratedPluginRegistrant

class MainActivity: FlutterFragmentActivity() {
    override fun configureFlutterEngine(flutterEngine: FlutterEngine) {
        GeneratedPluginRegistrant.registerWith(flutterEngine)
    }
}

Answer 2

从 FlutterActivity 更改会导致依赖于它的其他插件不起作用。 （如果有人知道为什么会这样，请在评论中告诉我）。

这为我解决了这个问题，将 android.name 中的“.MainActivity”更改为“io.flutter.embedding.android.FlutterFragmentActivity”。 但是，像下面的代码那样做使我们无法在 MainActivity 中自定义或编辑。

 <application
    ...
    <activity
        android:name="io.flutter.embedding.android.FlutterFragmentActivity" 
        android:launchMode="singleTop"
        android:theme="@style/LaunchTheme"