从Google Play商店安装应用后，应用崩溃

Question

因此，我刚刚将应用程序首次上传到了Google Play商店（位于Alpha中）。

但是，当我安装并打开该应用程序时，它崩溃了。 但是，如果我只是通过Android Studio运行它，它就可以正常工作。

这是Firebase崩溃报告指出的导致崩溃的错误：

Exception java.lang.NullPointerException: Attempt to invoke virtual method 'int java.lang.Integer.intValue()' on a null object reference
android.support.design.widget.CoordinatorLayout.onLayout (CoordinatorLayout.java)
android.view.View.layout (View.java:18793)
android.view.ViewGroup.layout (ViewGroup.java:5952)
android.support.v4.widget.DrawerLayout.onLayout (DrawerLayout.java)
android.view.View.layout (View.java:18793)
android.view.ViewGroup.layout (ViewGroup.java:5952)
android.widget.FrameLayout.layoutChildren (FrameLayout.java:323)
android.widget.FrameLayout.onLayout (FrameLayout.java:261)
android.view.View.layout (View.java:18793)
android.view.ViewGroup.layout (ViewGroup.java:5952)
android.widget.LinearLayout.setChildFrame (LinearLayout.java:1741)
android.widget.LinearLayout.layoutVertical (LinearLayout.java:1585)
android.widget.LinearLayout.onLayout (LinearLayout.java:1494)
android.view.View.layout (View.java:18793)
android.view.ViewGroup.layout (ViewGroup.java:5952)
android.widget.FrameLayout.layoutChildren (FrameLayout.java:323)
android.widget.FrameLayout.onLayout (FrameLayout.java:261)
android.view.View.layout (View.java:18793)
android.view.ViewGroup.layout (ViewGroup.java:5952)
android.widget.LinearLayout.setChildFrame (LinearLayout.java:1741)
android.widget.LinearLayout.layoutVertical (LinearLayout.java:1585)
android.widget.LinearLayout.onLayout (LinearLayout.java:1494)
android.view.View.layout (View.java:18793)
android.view.ViewGroup.layout (ViewGroup.java:5952)
android.widget.FrameLayout.layoutChildren (FrameLayout.java:323)
android.widget.FrameLayout.onLayout (FrameLayout.java:261)
com.android.internal.policy.DecorView.onLayout (DecorView.java:818)
android.view.View.layout (View.java:18793)
android.view.ViewGroup.layout (ViewGroup.java:5952)
android.view.ViewRootImpl.performLayout (ViewRootImpl.java:2625)
android.view.ViewRootImpl.performTraversals (ViewRootImpl.java:2341)
android.view.ViewRootImpl.doTraversal (ViewRootImpl.java:1493)

是什么导致此错误？ 当我的所有班级都没有列出此错误时，如何推断出问题所在？

Answer 1

找到了解决方案：

我正在使用Retrofit以及一些POJO模型类。 我需要proguard-rules.pro下行添加到proguard-rules.pro文件中：

-keep class package.to.models.** { *; }