ads_flutter 是一个用于在 Flutter 应用中展示广告的插件。它支持多种广告格式，如横幅广告、插页式广告、原生广告和激励视频广告。以下是使用 ads_flutter 插件的基本步骤：

1. 添加依赖

首先，你需要在 pubspec.yaml 文件中添加 ads_flutter 插件的依赖：

dependencies:
  flutter:
    sdk: flutter
  ads_flutter: ^latest_version

然后运行 flutter pub get 来获取依赖。

2. 初始化广告 SDK

在应用启动时，你需要初始化广告 SDK。通常情况下，你可以在 main.dart 文件中进行初始化：

import 'package:ads_flutter/ads_flutter.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await AdsFlutter.initialize(
    androidAppId: 'your_android_app_id',
    iosAppId: 'your_ios_app_id',
  );
  runApp(MyApp());
}

3. 展示横幅广告

横幅广告通常显示在屏幕的顶部或底部。你可以使用 BannerAd 组件来展示横幅广告：

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

class MyHomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Banner Ad Example'),
      ),
      body: Column(
        children: [
          Expanded(
            child: Center(
              child: Text('Your app content here'),
            ),
          ),
          BannerAd(
            adUnitId: 'your_banner_ad_unit_id',
            size: AdSize.banner,
            listener: (AdEvent event) {
              print('Banner Ad event: $event');
            },
          ),
        ],
      ),
    );
  }
}

4. 展示插页式广告

插页式广告通常在全屏模式下展示。你可以在用户执行某些操作（如点击按钮）时展示插页式广告：

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

class MyHomePage extends StatelessWidget {
  final InterstitialAd interstitialAd = InterstitialAd(
    adUnitId: 'your_interstitial_ad_unit_id',
    listener: (AdEvent event) {
      print('Interstitial Ad event: $event');
    },
  );

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Interstitial Ad Example'),
      ),
      body: Center(
        child: ElevatedButton(
          onPressed: () {
            interstitialAd.load();
            interstitialAd.show();
          },
          child: Text('Show Interstitial Ad'),
        ),
      ),
    );
  }
}

5. 展示激励视频广告

激励视频广告通常用于奖励用户观看视频。你可以在用户完成观看后给予奖励：

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

class MyHomePage extends StatelessWidget {
  final RewardedAd rewardedAd = RewardedAd(
    adUnitId: 'your_rewarded_ad_unit_id',
    listener: (AdEvent event, {RewardItem? reward}) {
      print('Rewarded Ad event: $event');
      if (event == AdEvent.rewarded) {
        // Grant the reward to the user
        print('Reward: ${reward?.amount} ${reward?.type}');
      }
    },
  );

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Rewarded Ad Example'),
      ),
      body: Center(
        child: ElevatedButton(
          onPressed: () {
            rewardedAd.load();
            rewardedAd.show();
          },
          child: Text('Show Rewarded Ad'),
        ),
      ),
    );
  }
}

6. 展示原生广告

原生广告是一种自定义广告格式，可以与应用的内容无缝集成：

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

class MyHomePage extends StatelessWidget {
  final NativeAd nativeAd = NativeAd(
    adUnitId: 'your_native_ad_unit_id',
    factoryId: 'your_native_ad_factory_id',
    listener: (AdEvent event) {
      print('Native Ad event: $event');
    },
  );

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Native Ad Example'),
      ),
      body: Center(
        child: Column(
          children: [
            Expanded(
              child: Center(
                child: Text('Your app content here'),
              ),
            ),
            NativeAdWidget(nativeAd: nativeAd),
          ],
        ),
      ),
    );
  }
}

7. 处理广告生命周期

确保在适当的时机加载和释放广告资源，以避免内存泄漏。例如，在页面销毁时释放广告资源：

@override
void dispose() {
  interstitialAd.dispose();
  rewardedAd.dispose();
  nativeAd.dispose();
  super.dispose();
}

8. 测试广告

在开发过程中，你可以使用测试广告单元 ID 和测试设备 ID 来确保广告正常工作。

await AdsFlutter.initialize(
  androidAppId: 'ca-app-pub-3940256099942544~3347511713',
  iosAppId: 'ca-app-pub-3940256099942544~1458002511',
  testDeviceIds: ['your_test_device_id'],
);