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。
本指南介绍了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
务必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。因此，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这些 ID 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 Android 项目引用此 API，请将以下代码行添加到 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<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
调用 MainActivity.configureFlutterEngine(FlutterEngine) 时，每个 NativeAdFactory 实现都必须使用 factoryId（一个唯一的 String 标识符）进行注册。稍后，在从 Dart 代码实例化原生广告时，将使用 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
在 iOS 中实现 Google 移动广告插件需要一个可实现 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 <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，在从 Dart 代码实例化原生广告时，将使用 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 一致。
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
如需以微件形式展示 NativeAd，您必须在调用 load() 之后实例化含有受支持广告的 AdWidget。您可以在调用 load() 之前创建微件，但必须先调用 load()，然后才能将该微件添加到微件树中。
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。