Proguard 使用 Android 导航组件导致运行时异常

Question

我在使用 proguard 将 NavigationComponent (android.arch.navigation:navigation-fragment-ktx:1.0.0-alpha01) 集成到我的项目中并使用 27 的目标编译 sdk 时遇到此崩溃

    2018-05-16 12:13:14.044 24573-24573/com.mypackage.myapp.x E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.mypackage.myapp.x, PID: 24573
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.mypackage.myapp.x/com.mypackage.myapp.MainActivity}: android.view.InflateException: Binary XML file line #16: Binary XML file line #16: Error inflating class fragment
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2925)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3060)
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:110)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:70)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1800)
        at android.os.Handler.dispatchMessage(Handler.java:106)
        at android.os.Looper.loop(Looper.java:164)
        at android.app.ActivityThread.main(ActivityThread.java:6649)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:826)
     Caused by: android.view.InflateException: Binary XML file line #16: Binary XML file line #16: Error inflating class fragment
     Caused by: android.view.InflateException: Binary XML file line #16: Error inflating class fragment
     Caused by: java.lang.RuntimeException: Exception inflating com.mypackage.myapp.x:navigation/nav_graph line 7
        at androidx.navigation.j.a(Unknown Source:124)
        at androidx.navigation.d.a(Unknown Source:4)
        at androidx.navigation.fragment.NavHostFragment.a(Unknown Source:88)
        at android.support.v4.app.Fragment.l(Unknown Source:15)
        at android.support.v4.app.m.a(Unknown Source:369)
        at android.support.v4.app.m.b(Unknown Source:7)
        at android.support.v4.app.m.a(Unknown Source:74)
        at android.support.v4.app.m.onCreateView(Unknown Source:216)
        at android.support.v4.app.j.a(Unknown Source:4)
        at android.support.v4.app.h.a(Unknown Source:2)
        at android.support.v4.app.d.onCreateView(Unknown Source:0)
        at android.support.v4.app.h.onCreateView(Unknown Source:0)
        at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:780)
        at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:730)
        at android.view.LayoutInflater.rInflate(LayoutInflater.java:863)
        at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:824)
        at android.view.LayoutInflater.rInflate(LayoutInflater.java:866)
        at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:824)
        at android.view.LayoutInflater.inflate(LayoutInflater.java:515)
        at android.view.LayoutInflater.inflate(LayoutInflater.java:423)
        at android.view.LayoutInflater.inflate(LayoutInflater.java:374)
        at android.support.v7.app.AppCompatDelegateImplV9.b(Unknown Source:23)
        at android.support.v7.app.d.setContentView(Unknown Source:4)
        at com.mypackage.myapp.MainActivity.onCreate(Unknown Source:12)
        at android.app.Activity.performCreate(Activity.java:7130)
        at android.app.Activity.performCreate(Activity.java:7121)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1262)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2905)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3060)
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:110)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:70)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1800)
        at android.os.Handler.dispatchMessage(Handler.java:106)
        at android.os.Looper.loop(Looper.java:164)
        at android.app.ActivityThread.main(ActivityThread.java:6649)
        at java.lang.reflect.Method.invoke(Native Method)
    2018-05-16 12:13:14.044 24573-24573/com.mypackage.myapp.x E/AndroidRuntime:     at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:826)
     Caused by: java.lang.RuntimeException: java.lang.ClassNotFoundException: com.mypackage.myapp.fragments.MainFragment
        at androidx.navigation.fragment.b$a.a(Unknown Source:58)
        at androidx.navigation.fragment.b$a.a(Unknown Source:19)
        at androidx.navigation.j.a(Unknown Source:16)
        at androidx.navigation.j.a(Unknown Source:133)
        at androidx.navigation.j.a(Unknown Source:31)
            ... 38 more
     Caused by: java.lang.ClassNotFoundException: com.mypackage.myapp.fragments.MainFragment
        at java.lang.Class.classForName(Native Method)
        at java.lang.Class.forName(Class.java:453)
        at androidx.navigation.fragment.b$a.a(Unknown Source:45)
            ... 42 more
     Caused by: java.lang.ClassNotFoundException: Didn't find class "com.mypackage.myapp.fragments.MainFragment" on path: DexPathList[[zip file "/system/framework/org.apache.http.legacy.boot.jar", zip file "/data/app/com.mypackage.myapp.x-ysts055HQTtJTv5J2uej3g==/base.apk"],nativeLibraryDirectories=[/data/app/com.mypackage.myapp.x-ysts055HQTtJTv5J2uej3g==/lib/x86, /system/lib]]
        at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:125)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:379)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:312)
            ... 45 more

可能是因为 AAPT 还没有为导航组件生成保留规则？

Answer 1

我知道 Proguard 和 R8 应该保留库 classes 的所有子项，但在这种情况下，片段 class 似乎丢失了。这个保留规则解决了我的问题，但从技术上讲我们根本不需要这个规则！

-keep class * extends android.support.v4.app.Fragment{}

如果您使用的是 AndroidX，则使用此规则：-keep class * extends androidx.fragment.app.Fragment{}

如果您在导航 XML 中使用 argType，您还需要为引用的 class 设置规则，例如：-keep class com.example.model.MyModel。或者更好的是，按照 official documentation 的建议，将可打包和可序列化的 classes 排除在重命名之外。 -keepnames class * extends android.os.Parcelable -keepnames class * extends java.io.Serializable

Answer 2

遇到过同样的问题。上面的答案给了我正确的研究方向。根据navigation docs

-keep class * extends android.support.v4.app.Fragment{} <-this is not needed

您需要做的就是保留通过安全参数传递的数据类的名称，例如

-keepnames class com.your.package.models.*

Answer 3

我的问题是我在布局上使用了片段名称。在 R8 之后，名称被混淆导致了这个问题。

<androidx.fragment.app.FragmentContainerView
    android:id="@+id/nav_host_fragment"                
    android:name="androidx.navigation.fragment.NavHostFragment"
    android:layout_width="match_parent"
    android:layout_height="match_parent""
    app:defaultNavHost="true"
    app:navGraph="@navigation/navigation_home" />

在我的例子中，解决方案是只在 Proguard 文件中保留名称，例如：

#-------------------------------------------------
# JetPack Navigation
# This fixes: Caused by: androidx.fragment.app.Fragment$InstantiationException: Unable to instantiate fragment androidx.navigation.fragment.NavHostFragment: make sure class name exists
#-------------------------------------------------
-keepnames class androidx.navigation.fragment.NavHostFragment

Answer 4

自 Android Gradle 插件 4.1 以来已修复此问题。

无需为 android:name 属性中定义的片段定义 Proguard 规则。

见https://issuetracker.google.com/issues/142601969

Proguard 使用 Android 导航组件导致运行时异常

Proguard causing runtime exception with Android Navigation Component

android

android-proguard

android-jetpack

android-architecture-navigation