Android AdMob报错：Cannot resolve symbol 'OnShowAdCompleteListener' 求解

问题描述 #

开发中遇到错误提示「Cannot resolve symbol 'OnShowAdCompleteListener'」，代码取自Google官方AdMob教程，已添加教程中相同的导入语句，其他代码均正常运行。相关代码如下：

/**
 * Show the ad if one isn't already showing.
 *
 * @param activity the activity that shows the app open ad
 * @param onShowAdCompleteListener the listener to be notified when an app open ad is complete
 */
private void showAdIfAvailable(
        @NonNull final Activity activity,
        @NonNull OnShowAdCompleteListener onShowAdCompleteListener) {
    // If the app open ad is already showing, do not show the ad again.
    if (isShowingAd) {
        //Log.d(LOG_TAG, "The app open ad is already showing.");
        return;
    }

    // If the app open ad is not available yet, invoke the callback then load the ad.
    if (!isAdAvailable()) {
        //Log.d(LOG_TAG, "The app open ad is not ready yet.");
        onShowAdCompleteListener.onShowAdComplete();
        loadAd(activity);
        return;
    }

    //Log.d(LOG_TAG, "Will show ad.");

    appOpenAd.setFullScreenContentCallback(
            new FullScreenContentCallback() {
                /** Called when full screen content is dismissed. */
                @Override
                public void onAdDismissedFullScreenContent() {
                    // Set the reference to null so isAdAvailable() returns false.
                    appOpenAd = null;
                    isShowingAd = false;

                    //Log.d(LOG_TAG, "onAdDismissedFullScreenContent.");
                    //Toast.makeText(activity, "onAdDismissedFullScreenContent", Toast.LENGTH_SHORT).show();

                    onShowAdCompleteListener.onShowAdComplete();
                    loadAd(activity);
                }

                /** Called when fullscreen content failed to show. */
                @Override
                public void onAdFailedToShowFullScreenContent(AdError adError) {
                    appOpenAd = null;
                    isShowingAd = false;

                    //Log.d(LOG_TAG, "onAdFailedToShowFullScreenContent: " + adError.getMessage());
                    //Toast.makeText(activity, "onAdFailedToShowFullScreenContent", Toast.LENGTH_SHORT).show();

                    onShowAdCompleteListener.onShowAdComplete();
                    loadAd(activity);
                }

                /** Called when fullscreen content is shown. */
                @Override
                public void onAdShowedFullScreenContent() {
                    //Log.d(LOG_TAG, "onAdShowedFullScreenContent.");
                    //Toast.makeText(activity, "onAdShowedFullScreenContent", Toast.LENGTH_SHORT).show();
                }
            });

    isShowingAd = true;
    appOpenAd.show(activity);
}

修复方案 #

1. 手动定义OnShowAdCompleteListener接口
   这个接口并非AdMob SDK自带，是官方示例自定义的回调接口。你需要在包含showAdIfAvailable方法的类（比如MyApplication）中添加以下代码：

public interface OnShowAdCompleteListener {
    void onShowAdComplete();
}

2. 清理重建项目
   在Android Studio中依次点击Build -> Clean Project，完成后再点击Build -> Rebuild Project，清除缓存后重新编译，解决符号识别异常问题。

3. 核对依赖版本
   确保项目中AdMob依赖版本与官方示例一致，在模块级build.gradle文件中检查依赖：

implementation 'com.google.android.gms:play-services-ads:22.6.0' // 版本号以示例为准

内容的提问来源于stack exchange，提问作者user19763422