flutter - 重新加载时奖励视频广告错误：“ad_not_loaded，奖励视频显示失败，未加载广告，空）”

Question

我尝试重新加载奖励视频广告，当我打电话时RewardedVideoAd.instance.load(adUnitId: "xxx", targetingInfo: xyz);发现以下错误：

W/MessageQueue(13672): Handler (android.os.Handler) {1a13e8a} 向死线程上的 Handler 发送消息 W/MessageQueue(13672): java.lang.IllegalStateException: Handler (android.os.Handler) {1a13e8a在死线程上向处理程序发送消息 java:1496) W/MessageQueue(13672)：在 com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1386) W/ExoPlayerImplInternal(13672)：发布后发送消息(1)。消息被忽略。D/Graph (13672): removeVertex() : insertDummyVertex，因为没有祖先。D/ViewRootImpl@b8db50eAdActivity：mHardwareRenderer.destroy()#4 D/ViewRootImpl@b8db50eAdActivity：dispatchDetachedFromWindow

我把听众放在initState()我的屏幕上。在这个屏幕上button，如果我们点击它，它应该显示 Rewarded Video Ads。

此外，在Rewarded Ads重新加载时出现错误后，我在点击按钮显示广告后出现以下错误（因为 ads 实例为null）：

E/flutter (13672): [ERROR:flutter/lib/ui/ui_dart_state.cc(148)] 未处理的异常：PlatformException(ad_not_loaded, 奖励视频显示失败，没有加载广告，空) E/flutter (13672): #0 StandardMethodCodec.decodeEnvelope (package:flutter/src/services/message_codecs.dart:564:7) E/flutter (13672): #1 MethodChannel.invokeMethod (package:flutter/src/services/platform_channel.dart:316:33 ) E/flutter (13672): E/flutter (13672): #2 _invokeBooleanMethod (package:firebase_admob/firebase_admob.dart:518:61) E/flutter (13672): E/flutter (13672): #3 RewardedVideoAd.show （包：firebase_admob/firebase_admob.dart:392:12）

我将Rewarded Video Ads Listener在initState()下面的代码：

@override
  void initState() {
    super.initState();
...
    RewardedVideoAd.instance.listener =
        (RewardedVideoAdEvent event, {String rewardType, int rewardAmount}) {
      if (event == RewardedVideoAdEvent.completed) {
        setState(() {
          print ("::debug:: ads should be reloaded");
          RewardedVideoAd.instance.load(adUnitId: "ca-app-pub-3940256099942544/5224354917", targetingInfo: targetingInfos);
        });
      }
    };
...

但是，如果我将代码放在onPressed下面的按钮上，视频广告将在点击 2-3 次后显示（在调试时显示ads = null）

RaisedButton(
  onPressed: () {
    RewardedVideoAd.instance.show().whenComplete(() {
              RewardedVideoAd.instance.load(adUnitId: "ca-app-pub-3940256099942544/5224354917", targetingInfo: targetingInfos);
    })    
},
...

任何的想法 ？

提前致谢...

Answer 1

似乎问题出在事件上completed。看看这个代码。

MobileAdTargetingInfo targetingInfo = MobileAdTargetingInfo(
  keywords: <String>['flutterio', 'beautiful apps'],
  contentUrl: 'https://flutter.io',
  childDirected: false,
  testDevices: <String>[], // Android emulators are considered test devices
);
bool _loaded = false;

@override
void initState() {
  super.initState();

  // load ad in the beginning
  RewardedVideoAd.instance
      .load(adUnitId: RewardedVideoAd.testAdUnitId, targetingInfo: targetingInfo)
      .catchError((e) => print("error in loading 1st time"))
      .then((v) => setState(() => _loaded = v));

  // ad listener
  RewardedVideoAd.instance.listener = (RewardedVideoAdEvent event, {String rewardType, int rewardAmount}) {
    if (event == RewardedVideoAdEvent.closed) {
      RewardedVideoAd.instance
          .load(adUnitId: RewardedVideoAd.testAdUnitId, targetingInfo: targetingInfo)
          .catchError((e) => print("error in loading again"))
          .then((v) => setState(() => _loaded = v));
    }
  };
}


@override
Widget build(BuildContext context) {
  return Scaffold(
    body: Center(
      child: Text(
        "Loaded = ${_loaded}",
        style: TextStyle(fontSize: 32, fontWeight: FontWeight.bold),
      ),
    ),
    floatingActionButton: FloatingActionButton(
      // show ad on FAB click
      onPressed: () async {
        await RewardedVideoAd.instance.show().catchError((e) => print("error in showing ad: ${e.toString()}"));
        setState(() => _loaded = false);
      },
    ),
  );
}

Answer 2

不需要调用 set state，因为它很昂贵并且会导致完全重建。

可以通过以下方式轻松解决此问题：

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

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
        title: 'Flutter Demo',
        theme: ThemeData(
          primarySwatch: Colors.blue,
        ),
        home: HomePage());
  }
}

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

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

class _HomePageState extends State<HomePage> {
  //The targeting info required for Rewarded Videos Ads
  MobileAdTargetingInfo targetingInfo = MobileAdTargetingInfo(
    keywords: <String>['flutterio', 'beautiful apps'],
    contentUrl: 'https://flutter.io',
    childDirected: false,
    testDevices: <String>[], // Android emulators are considered test devices
  );

  //An instance to be called in the init state
  RewardedVideoAd _videoAd = RewardedVideoAd.instance;

  @override
  void initState() {
    //---------------------------------------//
    //Initialise the listener with the values.
    _videoAd.listener =
        (RewardedVideoAdEvent event, {String rewardType, int rewardAmount}) {
      if (event == RewardedVideoAdEvent.completed) {
        //When the video ad gets completed load a new video ad
        _videoAd
            .load(
                adUnitId: RewardedVideoAd.testAdUnitId,
                targetingInfo: targetingInfo)
            .catchError((e) => print('Error in loading.'));
      }

      //On every other event change pass the values to the _handleEvent Method.
      _handleEvent(event, rewardType, 'Reward', rewardAmount);
    };
    //------------------------------------------------------------------//

    //This will load the video when the widget is built for the first time.
    _videoAd
        .load(
            adUnitId: RewardedVideoAd.testAdUnitId,
            targetingInfo: targetingInfo)
        .catchError((e) => print('Error in loading.'));

    //-----------------------------------------------------//
    super.initState();
  }

  //---- Useful function to know exactly what is being done ----//
  void _handleEvent(RewardedVideoAdEvent event, String rewardType,
      String adType, int rewardAmount) {
    switch (event) {
      case RewardedVideoAdEvent.loaded:
        _showSnackBar('New Admob $adType Ad loaded!', 1500);
        break;
      case RewardedVideoAdEvent.opened:
        _showSnackBar('Admob $adType Ad opened!', 1500);
        break;
      //
      //The way we are fixing the issue is here.
      //This is by calling the video to be loaded when the other rewarded video is closed.
      case RewardedVideoAdEvent.closed:
        _showSnackBar('Admob $adType Ad closed!', 1500);
        _videoAd
            .load(
                adUnitId: RewardedVideoAd.testAdUnitId,
                targetingInfo: targetingInfo)
            .catchError((e) => print('Error in loading.'));
        break;
      case RewardedVideoAdEvent.failedToLoad:
        _showSnackBar('Admob $adType failed to load.', 1500);
        break;
      case RewardedVideoAdEvent.rewarded:
        _showSnackBar('Rewarded $rewardAmount', 3000);
        break;
      default:
    }
  }

  //Snackbar shown with ad status
  void _showSnackBar(String content, int duration) {
    Scaffold.of(context).showSnackBar(SnackBar(
      content: Text(content),
      duration: Duration(milliseconds: duration),
    ));
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: FlatButton(
          child: Text('Play AD'),
          onPressed: () {
            _videoAd.show().catchError(
                (e) => print("error in showing ad: ${e.toString()}"));
          },
        ),
      ),
    );
  }
}