14

该代码适用于 pre-oreo 设备，但 Crashlytics 称它在 android 8 设备上崩溃

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getAppComponent().inject(this);
        binding = DataBindingUtil.setContentView(this, R.layout.main_activity);
    }

堆栈跟踪

java.lang.NullPointerException：尝试在空对象引用上调用虚拟方法“int android.view.ViewGroup.getChildCount()”

Caused by java.lang.NullPointerException: Attempt to invoke virtual method 'int android.view.ViewGroup.getChildCount()' on a null object reference
       at android.databinding.DataBindingUtil.bindToAddedViews(DataBindingUtil.java:295)
       at android.databinding.DataBindingUtil.setContentView(DataBindingUtil.java:279)
       at android.databinding.DataBindingUtil.setContentView(DataBindingUtil.java:261)
       at com.myapp.MyActivity.onCreate(MyActivity.java:59)
       at android.app.Activity.performCreate(Activity.java:7174)
       at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1220)
       at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2910)
       at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3032)
       at android.app.ActivityThread.-wrap11(Unknown Source)
       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1696)
       at android.os.Handler.dispatchMessage(Handler.java:105)
       at android.os.Looper.loop(Looper.java:164)
       at android.app.ActivityThread.main(ActivityThread.java:6940)
       at java.lang.reflect.Method.invoke(Method.java)
       at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:327)
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1374)
4

1 回答 1

17

在 8 上使用完全相同的堆栈跟踪发生类似的崩溃。

您是否尝试过使用：

binding = DataBindingUtil.inflate(getLayoutInflater(), R.layout.activity, null, false);
setContentView(binding.getRoot());

上面的代码和调用之间的区别

DataBindingUtil.setContentView(...);

是直接inflate()返回 a View，然后将其传递给DataBindingUtils::bindToAddedViews. 如果DataBindingUtil.setContentView使用以下逻辑

activity.setContentView(layoutId);
View decorView = activity.getWindow().getDecorView();
ViewGroup contentView = (ViewGroup) decorView.findViewById(android.R.id.content);

似乎

ViewGroup contentView = (ViewGroup) decorView.findViewById(android.R.id.content);

只是NULL……

于 2018-05-04T15:51:57.763 回答