"MissingPluginException(No implementation found for method getDatabasesPath on channel com.tekartik.sqflite)" 当我使用地板数据库时

"MissingPluginException(No implementation found for method getDatabasesPath on channel com.tekartik.sqflite)" when i use floor database

我正在尝试使用 floor 数据库,但是当我想建立数据库时,我遇到了 错误 :

E/flutter (26007): [ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: MissingPluginException(No implementation found for method getDatabasesPath on channel com.tekartik.sqflite)
E/flutter (26007): #0      MethodChannel._invokeMethod (package:flutter/src/services/platform_channel.dart:154:7)
E/flutter (26007): <asynchronous suspension>
E/flutter (26007): #1      MethodChannel.invokeMethod (package:flutter/src/services/platform_channel.dart:329:12)
E/flutter (26007): #2      invokeMethod (package:sqflite/src/sqflite_impl.dart:17:13)
E/flutter (26007): #3      SqfliteDatabaseFactoryImpl.invokeMethod (package:sqflite/src/factory_impl.dart:82:7)
E/flutter (26007): #4      SqfliteDatabaseFactoryMixin.safeInvokeMethod.<anonymous closure> (package:sqflite_common/src/factory_mixin.dart:25:35)
E/flutter (26007): #5      wrapDatabaseException (package:sqflite/src/exception_impl.dart:7:32)
E/flutter (26007): #6      SqfliteDatabaseFactoryImpl.wrapDatabaseException (package:sqflite/src/factory_impl.dart:78:7)
E/flutter (26007): #7      SqfliteDatabaseFactoryMixin.safeInvokeMethod (package:sqflite_common/src/factory_mixin.dart:25:7)
E/flutter (26007): #8      SqfliteDatabaseFactoryMixin.getDatabasesPath (package:sqflite_common/src/factory_mixin.dart:143:26)
E/flutter (26007): #9      getDatabasesPath (package:sqflite/sqflite.dart:168:54)
E/flutter (26007): #10     DatabaseFactoryExtension.getDatabasePath (package:floor/src/sqflite_database_factory.dart:23:23)
E/flutter (26007): #11     _$AppDatabaseBuilder.build (package:fluttermiwallet/db/database.g.dart:46:40)
E/flutter (26007): #12     main (package:fluttermiwallet/main.dart:9:67)
E/flutter (26007): #13     _runMainZoned.<anonymous closure>.<anonymous closure> (dart:ui/hooks.dart:241:25)
E/flutter (26007): #14     _rootRun (dart:async/zone.dart:1184:13)
E/flutter (26007): #15     _CustomZone.run (dart:async/zone.dart:1077:19)
E/flutter (26007): #16     _runZoned (dart:async/zone.dart:1619:10)
E/flutter (26007): #17     runZonedGuarded (dart:async/zone.dart:1608:12)
E/flutter (26007): #18     _runMainZoned.<anonymous closure> (dart:ui/hooks.dart:233:5)
E/flutter (26007): #19     _startIsolate.<anonymous closure> (dart:isolate-patch/isolate_patch.dart:301:19)
E/flutter (26007): #20     _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:168:12)

我的flutter版本:

Flutter 1.17.5 • channel stable • https://github.com/flutter/flutter.git
Framework • revision 8af6b2f038 (13 days ago) • 2020-06-30 12:53:55 -0700
Engine • revision ee76268252
Tools • Dart 2.8.4

floor的版本,floor_generator和build_runner如下:

environment:
  sdk: ">=2.7.0 <3.0.0"

dependencies:
  flutter:
    sdk: flutter
  cupertino_icons: ^0.1.3
  floor: ^0.13.0

dev_dependencies:
  flutter_test:
    sdk: flutter
  floor_generator: ^0.13.0
  build_runner: ^1.7.3

main.dart 中,我使用 $FloorAppDatabase 构建我的数据库:

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  var db = await $FloorAppDatabase.databaseBuilder('mydb.db').build();
  runApp(MyApp(db));
}

并在 android 文件夹中 GeneratedPluginRegistrant.java:

package io.flutter.plugins;

import androidx.annotation.Keep;
import androidx.annotation.NonNull;

import io.flutter.embedding.engine.FlutterEngine;
import io.flutter.embedding.engine.plugins.shim.ShimPluginRegistry;

/**
 * Generated file. Do not edit.
 * This file is generated by the Flutter tool based on the
 * plugins that support the Android platform.
 */
@Keep
public final class GeneratedPluginRegistrant {
  public static void registerWith(@NonNull FlutterEngine flutterEngine) {
    ShimPluginRegistry shimPluginRegistry = new ShimPluginRegistry(flutterEngine);
      io.flutter.plugins.flutter_plugin_android_lifecycle.FlutterAndroidLifecyclePlugin.registerWith(shimPluginRegistry.registrarFor("io.flutter.plugins.flutter_plugin_android_lifecycle.FlutterAndroidLifecyclePlugin"));
    flutterEngine.getPlugins().add(new io.flutter.plugins.imagepicker.ImagePickerPlugin());
    flutterEngine.getPlugins().add(new io.flutter.plugins.pathprovider.PathProviderPlugin());
    flutterEngine.getPlugins().add(new io.flutter.plugins.sharedpreferences.SharedPreferencesPlugin());
    flutterEngine.getPlugins().add(new com.tekartik.sqflite.SqflitePlugin());
  }
}

MainActivity.kt:

import android.os.Bundle
import io.flutter.app.FlutterActivity
import io.flutter.plugins.imagepicker.ImagePickerPlugin


class MainActivity : FlutterActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        ImagePickerPlugin.registerWith(
                registrarFor("io.flutter.plugins.imagepicker.ImagePickerPlugin"))

    }

}

我会尝试几种方法:

  • 首先通过尝试使用 SharedPreferences 而不是 sqflite 来确保所有插件确实已注册
  • 遵循插件迁移指南:https://flutter.dev/docs/development/packages-and-plugins/plugin-api-migration如果您的应用不是最近创建的
  • 尝试在 onCreate 中删除 ImagePickerPlugin 注册(或者基本上去掉 MainActivity 中的 onCreate)。
  • 尝试删除android文件夹并重新创建项目

我终于找到了答案。 我必须在我的 MainActivity 中添加 Sqflite 插件:SqflitePlugin.registerWith(registrarFor("com.tekartik.sqflite.SqflitePlugin"))

我的 MainActivity 更改如下:

import android.os.Bundle
import io.flutter.app.FlutterActivity
import io.flutter.plugins.imagepicker.ImagePickerPlugin
import com.tekartik.sqflite.SqflitePlugin


class MainActivity : FlutterActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        ImagePickerPlugin.registerWith(
                registrarFor("io.flutter.plugins.imagepicker.ImagePickerPlugin"))
        SqflitePlugin.registerWith(registrarFor("com.tekartik.sqflite.SqflitePlugin"))

    }

}

这是由于新添加的依赖项导致的,在我的例子中,以下命令起作用了。 去终端然后

flutter clean

并重新 运行 项目

就我而言,我已完成以下步骤以使其正常工作:

  • 在您拥有 MainActivity 的同一包中为 android 创建应用程序 class(如果尚未创建)。

MyApp.kt

package com.example.flutter_example

import io.flutter.app.FlutterApplication;
import io.flutter.plugin.common.PluginRegistry;
import io.flutter.plugin.common.PluginRegistry.PluginRegistrantCallback;
import com.tekartik.sqflite.SqflitePlugin

class MyApp : FlutterApplication(), PluginRegistrantCallback {

    override fun registerWith(registry: PluginRegistry) {
        com.tekartik.sqflite.SqflitePlugin.registerWith(
                registry.registrarFor("com.tekartik.sqflite.SqflitePlugin"))
    }
}
  • 现在更新您的 Android 清单文件并提供您的应用程序 class。
<application
        android:name=".MyApp"
  • 现在清理 运行 项目。
flutter clean
flutter run

这对我有用。

如果您仅在发布版本时遇到此问题,请使用混淆规则构建您的发布应用程序

    buildTypes {
        release {
            signingConfig signingConfigs.debug
            minifyEnabled true
            useProguard true
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }

在目录android/app/上创建一个文件,将文件命名为proguard-rules.pro并在里面写上:

#Flutter Wrapper
-keep class io.flutter.app.** { *; }
-keep class io.flutter.plugin.**  { *; }
-keep class io.flutter.util.**  { *; }
-keep class io.flutter.view.**  { *; }
-keep class io.flutter.**  { *; }
-keep class io.flutter.plugins.**  { *; }
-keep class androidx.lifecycle.DefaultLifecycleObserver

不使用 HotReload / 运行,停止应用程序并重新启动。

愚蠢的我,我在 Chrome 中尝试 运行 我的 sqflite 应用程序时 运行 遇到了这个错误。当然 sqflite 不支持网络,所以我不应该对它抛出错误感到惊讶! 运行 在移动模拟器(或 macOS)中应该可以工作。