Flutter Android 错误:必须在启动初始化后调用 ensureInitializationComplete

Question

目前我正在尝试将颤振应用程序添加到我的 android 应用程序中，但是当我尝试执行 Intent 时，应用程序崩溃并打印以下问题：

我在这里遵循了本指南

我收到此错误：

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.testappandroid/io.flutter.embedding.android.FlutterActivity}: java.lang.IllegalStateException: ensureInitializationComplete must be called after startInitialization
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2913)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3048)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1808)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:6669)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
Caused by: java.lang.IllegalStateException: ensureInitializationComplete must be called after startInitialization
at io.flutter.view.FlutterMain.ensureInitializationComplete(FlutterMain.java:168)
at io.flutter.embedding.android.FlutterActivityAndFragmentDelegate.initializeFlutter(FlutterActivityAndFragmentDelegate.java:177)
at io.flutter.embedding.android.FlutterActivityAndFragmentDelegate.onAttach(FlutterActivityAndFragmentDelegate.java:140)
at io.flutter.embedding.android.FlutterActivity.onCreate(FlutterActivity.java:399)
at android.app.Activity.performCreate(Activity.java:7136)
at android.app.Activity.performCreate(Activity.java:7127)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1271)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2893)

所以它说：确保初始化完成必须在启动初始化后调用。一种解决方案是在 Flutter Activity 中调用 FlutterMain.startInitialization(this(。但这对我不起作用：

我的颤振活动：

public class MainActivity extends FlutterActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
FlutterMain.startInitialization(this);
super.onCreate(savedInstanceState);
GeneratedPluginRegistrant.registerWith(this);
}
}

我的安卓应用程序安卓清单：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
package="com.example.testappandroid">
<uses-permission android:name="android.permission.INTERNET" />
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme"
tools:ignore="GoogleAppIndexingWarning">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="io.flutter.embedding.android.FlutterActivity"
android:theme="@style/AppTheme"
android:configChanges="orientation|keyboardHidden|keyboard|screenSize|locale|layoutDirection|fontScale|screenLayout|density"
android:hardwareAccelerated="true"
android:windowSoftInputMode="adjustResize"
android:exported="true">
<meta-data
android:name="io.flutter.Entrypoint"
android:value="main"
/>
</activity>
</application>
</manifest>

我的颤振模块安卓清单：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.testappflutter.host">
<!-- The INTERNET permission is required for development. Specifically,
flutter needs it to communicate with the running application
to allow setting breakpoints, to provide hot reload, etc.
-->
<uses-permission android:name="android.permission.INTERNET"/>
<!-- io.flutter.app.FlutterApplication is an android.app.Application that
calls FlutterMain.startInitialization(this); in its onCreate method.
In most cases you can leave this as-is, but you if you want to provide
additional functionality it is fine to subclass or reimplement
FlutterApplication and put your custom class here. -->
<application
android:name="io.flutter.app.FlutterApplication"
android:label="testappflutter"
android:icon="@mipmap/ic_launcher">
<activity
android:name=".MainActivity"
android:launchMode="singleTop"
android:theme="@style/LaunchTheme"
android:configChanges="orientation|keyboardHidden|keyboard|screenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
android:hardwareAccelerated="true"
android:windowSoftInputMode="adjustResize">
<!-- This keeps the window background of the activity showing
until Flutter renders its first frame. It can be removed if
there is no splash screen (such as the default splash screen
defined in @style/LaunchTheme). -->
<meta-data
android:name="io.flutter.app.android.SplashScreenUntilFirstFrame"
android:value="true" />
<intent-filter>
<action android:name="android.intent.action.MAIN"/>
<category android:name="android.intent.category.LAUNCHER"/>
</intent-filter>
</activity>
</application>
</manifest>

使用这行代码，我尝试打开FlutterActivtiy。这是在我的飞镖代码中调用main((函数：

Intent defaultFlutter = createDefaultIntent(activity);
activity.startActivity(defaultFlutter);

上面的代码应该从这个开始：

void main() => runApp(MaterialApp(
routes: {
"/": (context) => TestWidget()
}
));

所以我一步一步地遵循了将 Flutter 添加到现有 android 应用程序的指南。我忘了什么吗？在我看来，也许颤振应用程序的AndroidManifest需要一些更改？知道我做错了什么吗？

Answer 1

请确保导入正确的包：

import io.flutter.embedding.android.FlutterActivity;
import io.flutter.embedding.engine.FlutterEngine;

而不是

import io.flutter.app.FlutterActivity

在您的主活动中，因此您的主活动应如下所示：

package com.example.example
import io.flutter.embedding.android.FlutterActivity;
import io.flutter.embedding.engine.FlutterEngine;
class MainActivity: FlutterActivity() {
}

Answer 2

FlutterMain.startInitialization(this);

在喜欢之前添加此行Super.Create

FlutterMain.startInitialization(this) //Added line
super.onCreate(savedInstanceState)
GeneratedPluginRegistrant.registerWith(this)

Answer 3

尽管消息ensureInitializationComplete must be called after startInitialization，但不需要调用它。以这种方式运行颤振活动：

FlutterMain.startInitialization(context)
startActivity(FlutterActivity.createDefaultIntent(context))

如果您收到崩溃NoClassDefFoundError(类DefaultLifecycleObserver(，请将此依赖项添加到您的 android 模块中：

implementation 'android.arch.lifecycle:common-java8:1.1.0'