android - Google 跟踪代码管理器空容器

Question

我正在尝试遵循此处描述的内容:https://developers.google.com/tag-manager/android/v4/#init这就是我所拥有的:

TagManager tagManager = TagManager.getInstance(this);
    tagManager.setVerboseLoggingEnabled(true);


    PendingResult<ContainerHolder> pending =
            tagManager.loadContainerPreferNonDefault("GTM-XXXXXX",
                    R.raw.gtm);


    pending.setResultCallback(new ResultCallback<ContainerHolder>() {
        @Override
        public void onResult(ContainerHolder containerHolder) {
            ContainerHolderSingleton.setContainerHolder(containerHolder);
            container = containerHolder.getContainer();
            Log.d("NICK","Inside onResult...") ;
            if (!containerHolder.getStatus().isSuccess()) {
                Log.e("CuteAnimals", "failure loading container");

                return;
            }

            ContainerLoadedCallback.registerCallbacksForContainer(container);
            containerHolder.setContainerAvailableListener(new ContainerLoadedCallback());

        }
    }, 3000, TimeUnit.MILLISECONDS);


    Log.d("NICK","Value: "+container.getString("test_value));

发生的是上面 Log 行的 NullPointerException 因为 container 为空:

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.nick.app/com.nick.app.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String com.google.android.gms.tagmanager.Container.getString(java.lang.String)' on a null object reference
                                                                     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416)
                                                                     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
                                                                     at android.app.ActivityThread.-wrap11(ActivityThread.java)
                                                                     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
                                                                     at android.os.Handler.dispatchMessage(Handler.java:102)
                                                                     at android.os.Looper.loop(Looper.java:148)
                                                                     at android.app.ActivityThread.main(ActivityThread.java:5422)
                                                                     at java.lang.reflect.Method.invoke(Native Method)
                                                                     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
                                                                     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
                                                                  Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String com.google.android.gms.tagmanager.Container.getString(java.lang.String)' on a null object reference

我为谷歌标签管理器启用了日志记录，我得到了在我看来是“正常”的行为:

05-16 11:53:04.865 22585-22662/com.nick.app V/GoogleTagManager: Deleted 0 expired items
05-16 11:53:04.867 22585-22585/com.nick.app V/GoogleTagManager: Attempting to load a container from the resource ID 2131034112 (com.nick.app:raw/gtm)
05-16 11:53:04.888 22585-22585/com.nick.app V/GoogleTagManager: The container was successfully loaded from the resource (using JSON file format)
05-16 11:53:04.903 22585-22664/com.nick.app V/GoogleTagManager: Attempting to load resource from disk
05-16 11:53:04.925 22585-22664/com.nick.app V/GoogleTagManager: loadAfterDelay: containerId=GTM-XXXXXXX delay=40721307
05-16 11:53:04.925 22585-22664/com.nick.app D/GoogleTagManager: Setting previous container version: NQ$0
05-16 11:53:04.929 22585-22664/com.nick.app V/GoogleTagManager: The Disk resource was successfully read.

而且我在 onResult 中的日志语句从未显示，这可以解释为什么 container 为空，因为这是唯一会发生任何初始化的位置。 onResult 是不是应该到达， container 应该被初始化？我对如何正确实现这件事感到有些困惑。

Answer 1

加载 ContainerHolder 是异步发生的，因此在您当前尝试从中记录值时尚未为其分配值。

您链接到的站点具有以下有关 onResult() 的文档。

The onResult method will be called as soon as one of the following happens:

1. a saved container is loaded
2. if there is no saved container, a network container is loaded
3. the specified timeout occurs

这意味着在 onResult(...) 被调用之前您不能访问 container，因为这是它被赋值的地方。您可以将日志语句移动到该方法中以测试检索值，并在此时对容器执行您需要执行的任何其他操作。

public void onResult(ContainerHolder containerHolder) {
    ContainerHolderSingleton.setContainerHolder(containerHolder);
    container = containerHolder.getContainer();

    Log.d("NICK","Inside onResult...") ;
    if (!containerHolder.getStatus().isSuccess()) {
        Log.e("CuteAnimals", "failure loading container");
        return;
    }

    ContainerLoadedCallback.registerCallbacksForContainer(container);
    containerHolder.setContainerAvailableListener(new ContainerLoadedCallback());

    // do whatever you want with the container at this point
    Log.d("NICK","Value: " + container.getString("test_value));
}