我想在同一活动中使用2个Admob原生广告，但大小不同。我已经成功地发布了一个广告现在我想在同一活动中再显示一个本地广告。怎么做才合适
活动中的Admob实现

private void populateUnifiedNativeAdView(UnifiedNativeAd nativeAd, UnifiedNativeAdView
            adView) {
        // Set the media view. Media content will be automatically populated in the media view once
        MediaView mediaView = adView.findViewById(R.id.ad_media);
        adView.setMediaView(mediaView);

        // 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 is guaranteed to be in every UnifiedNativeAd.
        ((TextView) adView.getHeadlineView()).setText(nativeAd.getHeadline());

        // These assets aren't guaranteed to be in every UnifiedNativeAd, 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 {
            ((TextView) adView.getAdvertiserView()).setText(nativeAd.getAdvertiser());
            adView.getAdvertiserView().setVisibility(View.VISIBLE);
        }

        // This method tells the Google Mobile Ads SDK that you have finished populating your
        // native ad view with this native ad. The SDK will populate the adView's MediaView
        // with the media content from this native ad.
        adView.setNativeAd(nativeAd);

        // Get the video controller for the ad. One will always be provided, even if the ad doesn't
        // have a video asset.
        VideoController vc = nativeAd.getVideoController();

        // Updates the UI to say whether or not this ad has a video asset.
        if (vc.hasVideoContent()) {

            // Create a new VideoLifecycleCallbacks object and pass it to the VideoController. The
            // VideoController will call methods on this object when events occur in the video
            // lifecycle.
            vc.setVideoLifecycleCallbacks(new VideoController.VideoLifecycleCallbacks() {
                @Override
                public void onVideoEnd() {
                    // Publishers should allow native ads to complete video playback before
                    // refreshing or replacing them with another ad in the same UI location.

                    super.onVideoEnd();
                }
            });
        } else {
        }
    }

    /**
     * Creates a request for a new native ad based on the boolean parameters and calls the
     * corresponding "populate" method when one is successfully returned.
     */
    private void refreshAd() {

        AdLoader.Builder builder = new AdLoader.Builder(this, getString(R.string.admob_native_advance));

        builder.forUnifiedNativeAd(new UnifiedNativeAd.OnUnifiedNativeAdLoadedListener() {
            @Override
            public void onUnifiedNativeAdLoaded(UnifiedNativeAd unifiedNativeAd) {
                // You must call destroy on old ads when you are done with them,
                // otherwise you will have a memory leak.
                if (nativeAd != null) {
                    nativeAd.destroy();
                }
//                nativeAd = unifiedNativeAd;
//
//
//                RelativeLayout relativeLayout =
//                        findViewById(R.id.fl_adplaceholder);
//                UnifiedNativeAdView adView = (UnifiedNativeAdView) getLayoutInflater()
//                        .inflate(R.layout.ad_unified, null);
//                populateUnifiedNativeAdView(unifiedNativeAd, adView);
//
//
//                relativeLayout.removeAllViews();
//                relativeLayout.addView(adView);

                NativeTemplateStyle styles = new
                        NativeTemplateStyle.Builder().build();
                TemplateView adView = findViewById(R.id.adview);
                adView.setVisibility(View.VISIBLE);
                adView.setStyles(styles);
                adView.setNativeAd(unifiedNativeAd);
            }

        });

        VideoOptions videoOptions = new VideoOptions.Builder()
                .build();

        NativeAdOptions adOptions = new NativeAdOptions.Builder()
                .setVideoOptions(videoOptions)
                .build();

        builder.withNativeAdOptions(adOptions);

        AdLoader adLoader = builder.withAdListener(new AdListener() {
            @Override
            public void onAdFailedToLoad(int errorCode) {
                Log.w(HELPER_TAG, "onAdFailedToLoad: " + errorCode);
            }
        }).build();

        adLoader.loadAd(new AdRequest.Builder()
                .build());
    }

第一个AdMob原生广告布局（成功实施）

<?xml version="1.0" encoding="utf-8"?>
<merge xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    >
    <com.google.android.gms.ads.formats.UnifiedNativeAdView
        android:id="@+id/native_ad_view"
        android:layout_width="match_parent"
        android:layout_height="120dp"
        android:layout_centerInParent="true"
        android:background="@color/dark_bg"
        >
        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_marginBottom="5dp"
            >
            <ImageView
                android:id="@+id/icon"
                android:layout_width="60dp"
                android:layout_height="60dp"
                android:layout_marginLeft="12dp"
                android:layout_marginTop="5dp"
                android:contentDescription="@null" />
            <TextView
                android:id="@+id/primary"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_alignTop="@id/icon"
                android:layout_alignParentRight="true"
                android:layout_marginLeft="14dp"
                android:layout_marginTop="8dp"
                android:layout_marginRight="10dp"
                android:layout_toRightOf="@id/icon"
                android:lines="1"
                android:textColor="@color/white"
                android:textSize="@dimen/gnt_text_size_large"
                android:textStyle="bold" />
            <LinearLayout
                android:id="@+id/second_row"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_below="@id/primary"
                android:layout_marginLeft="14dp"
                android:layout_marginTop="6dp"
                android:layout_marginRight="10dp"
                android:layout_toRightOf="@id/icon"
                android:orientation="horizontal">
                <RatingBar
                    android:id="@+id/rating_bar"
                    android:layout_width="wrap_content"
                    android:layout_height="@dimen/gnt_ad_indicator_height"
                    android:lines="1"
                    android:numStars="0"
                    android:textColor="@color/white"
                    android:textSize="@dimen/gnt_text_size_small" />
                <TextView
                    android:id="@+id/secondary"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    android:layout_marginStart="@dimen/gnt_no_margin"
                    android:layout_marginTop="@dimen/gnt_no_margin"
                    android:layout_marginEnd="@dimen/gnt_no_margin"
                    android:layout_marginBottom="@dimen/gnt_no_margin"
                    android:gravity="top"
                    android:lines="1"
                    android:textColor="@color/white"
                    android:textSize="@dimen/gnt_text_size_small" />
            </LinearLayout>
            <Button
                android:id="@+id/cta"
                android:layout_width="250dp"
                android:layout_height="0dp"
                android:layout_below="@id/icon"
                android:layout_marginLeft="10dp"
                android:layout_marginTop="5dp"
                android:layout_marginRight="10dp"
                android:layout_marginBottom="5dp"
                android:background="@drawable/main_ad_button"
                android:lines="1"
                android:layout_alignParentBottom="true"
                android:layout_alignParentEnd="true"
                android:textColor="@color/gnt_white"
                android:layout_alignParentRight="true" />
            <RelativeLayout
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:background="@drawable/ad_text_background"
                >
                <TextView
                    android:id="@+id/ad_notification_view"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_margin="5dp"
                    android:text="Ad"
                    android:textColor="@color/white_color"
                    android:textSize="@dimen/gnt_ad_indicator_text_size"
                    android:textStyle="bold" />
            </RelativeLayout>
        </RelativeLayout>
    </com.google.android.gms.ads.formats.UnifiedNativeAdView>
</merge>

第二个AdMob布局文件（需要实现）

<com.google.android.gms.ads.formats.UnifiedNativeAdView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:background="@color/dark_bg"
        android:minHeight="50dp"
        android:orientation="vertical">

        <TextView style="@style/AppTheme.AdAttribution"/>

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            android:paddingLeft="20dp"
            android:paddingRight="20dp"
            android:paddingTop="0dp">

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:orientation="horizontal">

                <ImageView
                    android:id="@+id/ad_app_icon"
                    android:layout_width="40dp"
                    android:layout_height="40dp"
                    android:adjustViewBounds="true"
                    android:paddingBottom="5dp"
                    android:paddingEnd="5dp"
                    android:paddingRight="5dp"/>

                <LinearLayout
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:orientation="vertical">

                    <TextView
                        android:id="@+id/ad_headline"
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        android:textColor="#0000FF"
                        android:textSize="12sp"
                        android:textStyle="bold" />

                    <LinearLayout
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content">

                        <TextView
                            android:id="@+id/ad_advertiser"
                            android:layout_width="wrap_content"
                            android:layout_height="match_parent"
                            android:gravity="bottom"
                            android:textSize="13sp"
                            android:textStyle="bold"/>

                        <RatingBar
                            android:id="@+id/ad_stars"
                            style="?android:attr/ratingBarStyleSmall"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:isIndicator="true"
                            android:numStars="5"
                            android:stepSize="0.5" />
                    </LinearLayout>

                </LinearLayout>
            </LinearLayout>

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:orientation="vertical">

                <TextView
                    android:id="@+id/ad_body"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_marginRight="20dp"
                    android:layout_marginEnd="20dp"
                    android:textSize="11sp" />

                <com.google.android.gms.ads.formats.MediaView
                    android:id="@+id/ad_media"
                    android:layout_gravity="center_horizontal"
                    android:layout_width="200dp"
                    android:layout_height="105dp"
                    android:layout_marginTop="5dp" />

                <LinearLayout
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_gravity="end"
                    android:orientation="horizontal"
                    android:paddingBottom="5dp"
                    android:paddingTop="5dp">

                    <TextView
                        android:id="@+id/ad_price"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:paddingLeft="5dp"
                        android:paddingStart="5dp"
                        android:paddingRight="5dp"
                        android:paddingEnd="5dp"
                        android:textSize="12sp" />

                    <TextView
                        android:id="@+id/ad_store"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:paddingLeft="5dp"
                        android:paddingStart="5dp"
                        android:paddingRight="5dp"
                        android:paddingEnd="5dp"
                        android:textSize="12sp" />

                    <Button
                        android:background="@drawable/main_ad_button"
                        android:id="@+id/ad_call_to_action"
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        android:gravity="center"
                        android:textSize="12sp" />
                </LinearLayout>
            </LinearLayout>
        </LinearLayout>
    </LinearLayout>
</com.google.android.gms.ads.formats.UnifiedNativeAdView>