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Android 和 iOS 中的原生设置

系统使用平台原生的界面组件（例如，Android 上的 View 或 iOS 上的 UIView）向用户展示原生广告。

本指南将向您介绍如何使用平台专用代码加载、展示和自定义原生广告。

前提条件

完成入门指南。
熟悉原生广告选项。

始终使用测试广告进行测试

在构建和测试应用时，请确保使用的是测试广告，而不是实际投放的广告。对于原生广告，加载测试广告最简便的方法就是使用我们的专用测试广告单元 ID：

/21775744923/example/native

这些测试广告单元 ID 已经过专门配置，可确保每个请求返回的都是测试广告。您可以在自己应用的编码、测试和调试过程中使用这些测试广告单元 ID，只需确保在发布应用前将其替换为自己的广告单元 ID 即可。

针对特定平台的设置

如需制作原生广告，您需要为 iOS 和 Android 编写特定于平台的代码，然后修改 Dart 实现，以利用您对原生代码所做的更改。

Android

导入插件

在 Android 中实现 Google 移动广告插件需要一个可实现 NativeAdFactory API 的类。如需从您的 Android 项目中引用此 API，请将以下行添加到 settings.gradle 中：

def flutterProjectRoot = rootProject.projectDir.parentFile.toPath()
def plugins = new Properties()
def pluginsFile = new File(flutterProjectRoot.toFile(), '.flutter-plugins')
if (pluginsFile.exists()) {
    pluginsFile.withInputStream { stream -> plugins.load(stream) }
}

plugins.each { name, path ->
    def pluginDirectory = flutterProjectRoot.resolve(path).resolve('android').toFile()
    include ":$name"
    project(":$name").projectDir = pluginDirectory
}

实现 NativeAdFactory

接下来，创建一个实现 NativeAdFactory 并替换 createNativeAd() 方法的类。

package io.flutter.plugins.googlemobileadsexample;

import android.graphics.Color;
import android.view.LayoutInflater;
import android.widget.TextView;
import com.google.android.gms.ads.nativead.NativeAd;
import com.google.android.gms.ads.nativead.NativeAdView;
import io.flutter.plugins.googlemobileads.GoogleMobileAdsPlugin.NativeAdFactory;
import java.util.Map;

/**
 * my_native_ad.xml can be found at
 * github.com/googleads/googleads-mobile-flutter/blob/main/packages/google_mobile_ads/
 *     example/android/app/src/main/res/layout/my_native_ad.xml
 */
class NativeAdFactoryExample implements NativeAdFactory {
  private final LayoutInflater layoutInflater;

  NativeAdFactoryExample(LayoutInflater layoutInflater) {
    this.layoutInflater = layoutInflater;
  }

  @Override
  public NativeAdView createNativeAd(
      NativeAd nativeAd, Map&lt;String, Object> customOptions) {
    final NativeAdView adView =
        (NativeAdView) layoutInflater.inflate(R.layout.my_native_ad, null);

    // Set the media view.
    adView.setMediaView((MediaView) adView.findViewById(R.id.ad_media));

    // Set other ad assets.
    adView.setHeadlineView(adView.findViewById(R.id.ad_headline));
    adView.setBodyView(adView.findViewById(R.id.ad_body));
    adView.setCallToActionView(adView.findViewById(R.id.ad_call_to_action));
    adView.setIconView(adView.findViewById(R.id.ad_app_icon));
    adView.setPriceView(adView.findViewById(R.id.ad_price));
    adView.setStarRatingView(adView.findViewById(R.id.ad_stars));
    adView.setStoreView(adView.findViewById(R.id.ad_store));
    adView.setAdvertiserView(adView.findViewById(R.id.ad_advertiser));

    // The headline and mediaContent are guaranteed to be in every NativeAd.
    ((TextView) adView.getHeadlineView()).setText(nativeAd.getHeadline());
    adView.getMediaView().setMediaContent(nativeAd.getMediaContent());

    // These assets aren't guaranteed to be in every NativeAd, so it's important to
    // check before trying to display them.
    if (nativeAd.getBody() == null) {
      adView.getBodyView().setVisibility(View.INVISIBLE);
    } else {
      adView.getBodyView().setVisibility(View.VISIBLE);
      ((TextView) adView.getBodyView()).setText(nativeAd.getBody());
    }

    if (nativeAd.getCallToAction() == null) {
      adView.getCallToActionView().setVisibility(View.INVISIBLE);
    } else {
      adView.getCallToActionView().setVisibility(View.VISIBLE);
      ((Button) adView.getCallToActionView()).setText(nativeAd.getCallToAction());
    }

    if (nativeAd.getIcon() == null) {
      adView.getIconView().setVisibility(View.GONE);
    } else {
      ((ImageView) adView.getIconView()).setImageDrawable(nativeAd.getIcon().getDrawable());
      adView.getIconView().setVisibility(View.VISIBLE);
    }

    if (nativeAd.getPrice() == null) {
      adView.getPriceView().setVisibility(View.INVISIBLE);
    } else {
      adView.getPriceView().setVisibility(View.VISIBLE);
      ((TextView) adView.getPriceView()).setText(nativeAd.getPrice());
    }

    if (nativeAd.getStore() == null) {
      adView.getStoreView().setVisibility(View.INVISIBLE);
    } else {
      adView.getStoreView().setVisibility(View.VISIBLE);
      ((TextView) adView.getStoreView()).setText(nativeAd.getStore());
    }

    if (nativeAd.getStarRating() == null) {
      adView.getStarRatingView().setVisibility(View.INVISIBLE);
    } else {
      ((RatingBar) adView.getStarRatingView()).setRating(nativeAd.getStarRating()
          .floatValue());
      adView.getStarRatingView().setVisibility(View.VISIBLE);
    }

    if (nativeAd.getAdvertiser() == null) {
      adView.getAdvertiserView().setVisibility(View.INVISIBLE);
    } else {
      adView.getAdvertiserView().setVisibility(View.VISIBLE);
      ((TextView) adView.getAdvertiserView()).setText(nativeAd.getAdvertiser());
    }

    // This method tells the Google Mobile Ads SDK that you have finished populating your
    // native ad view with this native ad.
    adView.setNativeAd(nativeAd);

    return adView;
  }
}

如需查看配置 NativeAdView 布局的示例，请参阅 my_native_ad.xml。

注册 NativeAdFactory

在调用 MainActivity.configureFlutterEngine(FlutterEngine) 时，每个 NativeAdFactory 实现都必须使用 factoryId（唯一的 String 标识符）注册。稍后通过 Dart 代码实例化原生广告时，将用到 factoryId。

您可以为应用所使用的每个唯一原生广告版式分别实现和注册一个 NativeAdFactory，也可以用单个 NativeAdFactory 处理所有版式。

请注意，在使用加入现有应用功能进行构建时，还应在 cleanUpFlutterEngine(engine) 中取消注册 NativeAdFactory。

创建 NativeAdFactoryExample 后，请按如下步骤设置 MainActivity：

package my.app.path;

import io.flutter.embedding.android.FlutterActivity;
import io.flutter.embedding.engine.FlutterEngine;
import io.flutter.plugins.googlemobileads.GoogleMobileAdsPlugin;

public class MainActivity extends FlutterActivity {
  @Override
  public void configureFlutterEngine(FlutterEngine flutterEngine) {
    flutterEngine.getPlugins().add(new GoogleMobileAdsPlugin());
    super.configureFlutterEngine(flutterEngine);

    GoogleMobileAdsPlugin.registerNativeAdFactory(flutterEngine,
        "adFactoryExample", NativeAdFactoryExample());
  }

  @Override
  public void cleanUpFlutterEngine(FlutterEngine flutterEngine) {
    GoogleMobileAdsPlugin.unregisterNativeAdFactory(flutterEngine, "adFactoryExample");
  }
}

iOS

实现 NativeAdFactory

Google 移动广告插件的 iOS 实现需要一个实现 FLTNativeAdFactory API 的类。创建一个实现 NativeAdFactory 的类，并实现 createNativeAd() 方法。

#import "FLTGoogleMobileAdsPlugin.h"

/**
 * The example NativeAdView.xib can be found at
 * github.com/googleads/googleads-mobile-flutter/blob/main/packages/google_mobile_ads/
 *     example/ios/Runner/NativeAdView.xib
 */
@interface NativeAdFactoryExample : NSObject &lt;FLTNativeAdFactory>
@end

@implementation NativeAdFactoryExample
- (GADNativeAdView *)createNativeAd:(GADNativeAd *)nativeAd
                      customOptions:(NSDictionary *)customOptions {
  // Create and place the ad in the view hierarchy.
  GADNativeAdView *adView =
      [[NSBundle mainBundle] loadNibNamed:@"NativeAdView" owner:nil options:nil].firstObject;

  // Populate the native ad view with the native ad assets.
  // The headline is guaranteed to be present in every native ad.
  ((UILabel *)adView.headlineView).text = nativeAd.headline;

  // These assets are not guaranteed to be present. Check that they are before
  // showing or hiding them.
  ((UILabel *)adView.bodyView).text = nativeAd.body;
  adView.bodyView.hidden = nativeAd.body ? NO : YES;

  [((UIButton *)adView.callToActionView) setTitle:nativeAd.callToAction
                                         forState:UIControlStateNormal];
  adView.callToActionView.hidden = nativeAd.callToAction ? NO : YES;

  ((UIImageView *)adView.iconView).image = nativeAd.icon.image;
  adView.iconView.hidden = nativeAd.icon ? NO : YES;

  ((UILabel *)adView.storeView).text = nativeAd.store;
  adView.storeView.hidden = nativeAd.store ? NO : YES;

  ((UILabel *)adView.priceView).text = nativeAd.price;
  adView.priceView.hidden = nativeAd.price ? NO : YES;

  ((UILabel *)adView.advertiserView).text = nativeAd.advertiser;
  adView.advertiserView.hidden = nativeAd.advertiser ? NO : YES;

  // In order for the SDK to process touch events properly, user interaction
  // should be disabled.
  adView.callToActionView.userInteractionEnabled = NO;

  // Associate the native ad view with the native ad object. This is
  // required to make the ad clickable.
  // Note: this should always be done after populating the ad views.
  adView.nativeAd = nativeAd;

  return adView;
}
@end

如需查看配置 GADNativeAdView 布局的示例，请参阅 NativeAdView.xib。

注册 NativeAdFactory

每个 FLTNativeAdFactory 都需要使用 factoryId（一个唯一的 String 标识符）在 registerNativeAdFactory:factoryId:nativeAdFactory: 中进行注册。稍后通过 Dart 代码实例化原生广告时，将会用到 factoryId。

您可以为应用所使用的每个唯一原生广告版式分别实现和注册一个 FLTNativeAdFactory，也可以用单个 FLTNativeAdFactory 处理所有版式。

创建 FLTNativeAdFactory 后，请按以下步骤设置 AppDelegate：

#import "FLTGoogleMobileAdsPlugin.h"
#import "NativeAdFactoryExample.h"

@implementation AppDelegate
- (BOOL)application:(UIApplication *)application
      didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
  [GeneratedPluginRegistrant registerWithRegistry:self];

  // Must be added after GeneratedPluginRegistrant registerWithRegistry:self];
  // is called.
  NativeAdFactoryExample *nativeAdFactory = [[NativeAdFactoryExample alloc] init];
  [FLTGoogleMobileAdsPlugin registerNativeAdFactory:self
                                          factoryId:@"adFactoryExample"
                                    nativeAdFactory:nativeAdFactory];

  return [super application:application didFinishLaunchingWithOptions:launchOptions];
}
@end

加载广告

添加平台专用代码后，请改用 Dart 加载广告。确保 factoryID 与您之前注册的 ID 匹配。

class NativeExampleState extends State<NativeExample> {
  NativeAd? _nativeAd;
  bool _nativeAdIsLoaded = false;

 // TODO: replace this test ad unit with your own ad unit.
 final _adUnitId = '/21775744923/example/native';

  /// Loads a native ad.
  void loadAd() {
    _nativeAd = NativeAd(
        adUnitId: _adUnitId,
        // Factory ID registered by your native ad factory implementation.
        factoryId: 'adFactoryExample',
        listener: NativeAdListener(
          onAdLoaded: (ad) {
            print('$NativeAd loaded.');
            setState(() {
              _nativeAdIsLoaded = true;
            });
          },
          onAdFailedToLoad: (ad, error) {
            // Dispose the ad here to free resources.
            print('$NativeAd failedToLoad: $error');
            ad.dispose();
          },
        ),
        request: const AdManagerAdRequest(),
        // Optional: Pass custom options to your native ad factory implementation.
        customOptions: {'custom-option-1', 'custom-value-1'}
    );
    _nativeAd.load();
  }
}

原生广告事件

若要在发生与原生广告互动相关的事件时收到通知，请使用广告的 listener 属性。然后，实现 NativeAdListener 以接收广告事件回调。

class NativeExampleState extends State<NativeExample> {
  NativeAd? _nativeAd;
  bool _nativeAdIsLoaded = false;

 // TODO: replace this test ad unit with your own ad unit.
 final _adUnitId = '/21775744923/example/native';

  /// Loads a native ad.
  void loadAd() {
    _nativeAd = NativeAd(
        adUnitId: _adUnitId,
        // Factory ID registered by your native ad factory implementation.
        factoryId: 'adFactoryExample',
        listener: NativeAdListener(
          onAdLoaded: (ad) {
            print('$NativeAd loaded.');
            setState(() {
              _nativeAdIsLoaded = true;
            });
          },
          onAdFailedToLoad: (ad, error) {
            // Dispose the ad here to free resources.
            print('$NativeAd failedToLoad: $error');
            ad.dispose();
          },
          // Called when a click is recorded for a NativeAd.
          onAdClicked: (ad) {},
          // Called when an impression occurs on the ad.
          onAdImpression: (ad) {},
          // Called when an ad removes an overlay that covers the screen.
          onAdClosed: (ad) {},
          // Called when an ad opens an overlay that covers the screen.
          onAdOpened: (ad) {},
          // For iOS only. Called before dismissing a full screen view
          onAdWillDismissScreen: (ad) {},
          // Called when an ad receives revenue value.
          onPaidEvent: (ad, valueMicros, precision, currencyCode) {},
        ),
        request: const AdManagerAdRequest(),
        // Optional: Pass custom options to your native ad factory implementation.
        customOptions: {'custom-option-1', 'custom-value-1'}
    );
    _nativeAd.load();
        
  }
}

展示广告

若要将 NativeAd 显示为 widget，您必须在调用 load() 后实例化包含受支持广告的 AdWidget。您可以在调用 load() 之前创建 widget，但必须先调用 load()，然后才能将其添加到 widget 树中。

AdWidget 继承自 Flutter 的 Widget 类，可以像其他任何微件一样使用。在 iOS 中，请确保将该微件放置在具有指定宽度和高度的容器中。否则，您的广告可能不会展示。

final Container adContainer = Container(
  alignment: Alignment.center,
  child: AdWidget adWidget = AdWidget(ad: _nativeAd!),
  width: WIDTH,
  height: HEIGHT,
);

销毁广告

当不再需要访问 NativeAd 时，必须将其处置。调用 dispose() 的最佳做法是，在将与原生广告关联的 AdWidget 从微件树中移除后，在 AdListener.onAdFailedToLoad() 回调中调用。