仅当minifyEnabled并与LifeCycle v 2.1.0一起使用时，应用程序才会在创建ViewModel时崩溃 [英] App crash on creating ViewModel only when minifyEnabled and with LifeCycle v 2.1.0
问题描述
使用 lazy {} 创建视图模型时，我的应用在启动时因 LinkageError 而崩溃.只有在以下情况下才会发生崩溃:
My app is crashing on launch with a LinkageError when creating a view model using lazy{}. The crash only happens when:
-
minifyEnabled在build.gradle和AND 中设置为 - 我使用 ver.2.1.0 生命周期组件.它与
lifecycle-2.0.0和minifyEnabled一起使用时效果很好
true minifyEnabledis set totruein build.gradle, AND- I use ver. 2.1.0 of lifecycle components. It works fine with
lifecycle-2.0.0withminifyEnabled
def lifecycle_version = '2.1.0'
implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:$lifecycle_version"
implementation "androidx.lifecycle:lifecycle-extensions:$lifecycle_version"
此外，崩溃仅发生在其中一种视图模型上.在同一活动之前接触过的其他视图模型不会使应用程序崩溃.
Also, the crash is only happening for one of the view models. Other view models in the same activity that are touched before this one, aren't crashing the app.
崩溃发生在第二行:
private val searchStackViewModel by lazy {
ViewModelProviders.of(this)[SearchStateViewModel::class.java]
}
SearchStateViewModel 是:
class SearchStateViewModel : ViewModel() {
// Live data that initialises to empty stack with SearchStack.init
private val privateStack = MutableLiveData<SearchStack>().apply {
value = SearchStack()
}
// Observable view of search stack so it can't be directly modified
internal val stateStack : LiveData<SearchStack> = privateStack
/**
* Add state to stack
*/
fun add(searchState: SearchState) {
val current = privateStack.value ?: SearchStack()
current.add(searchState)
privateStack.value = current
}
/**
* Clear stack
*/
fun clear() {
val current = privateStack.value ?: SearchStack()
current.clear()
privateStack.value = current
}
/**
* Clear stack, then add current state as the only state
*/
fun clearThenAdd(searchState: SearchState) {
val current = privateStack.value ?: SearchStack()
current.clear()
current.add(searchState)
privateStack.value = current
}
/**
* Get currentState search state, without changing the stack
*/
fun currentState(): SearchState {
return privateStack.value?.last() ?: SearchState()
}
/**
* Return currentState search state, and remove it from the stack
*/
fun pop(): SearchState {
val current = privateStack.value ?: SearchStack()
val poppedState = current.pop()
privateStack.value = current
return poppedState
}
}
SearchStack 只是一个ArrayList:
SearchStack is just an ArrayList:
class SearchStack : ArrayList<SearchState>() {
init {
add(SearchState())
}
fun pop(): SearchState = if (lastIndex > 0) removeAt(lastIndex) else last()
override fun clear() {
super.clear()
add(SearchState())
}
override fun add(element: SearchState): Boolean {
if (element == lastOrNull())
return false
return super.add(element)
}
}
SearchState 是一个数据类:
@Parcelize
data class SearchState(
val searchTerm: String = "",
val isComplete: Boolean? = null,
val dueOnly: Boolean = false,
val aliveOnly: Boolean = true,
val priority: Char? = null,
val project: String? = null,
val priorityMatchType: PriorityMatchType? = null,
val name: String = "",
val hideThresholdTasks: Boolean = true,
val sortOrder: Int = -1,
val sortOrderString: String? = null
) : Parcelable {
enum class PriorityMatchType {
GREATOR,
LESSOR,
EXACT
}
enum class TaskState {
DUE,
PENDING,
COMPLETED,
ALL
}
Stacktrace:
Stacktrace:
FATAL EXCEPTION: main
Process: net.c306.ttsuper, PID: 7380
java.lang.LinkageError: i.a.a.o.b
1 >> at net.c306.ttsuper.view.ui.MainActivity$v.b(SourceFile:182)
at net.c306.ttsuper.view.ui.MainActivity$v.b(SourceFile:159)
at g.j.a(SourceFile:74)
at net.c306.ttsuper.view.ui.MainActivity.F(SourceFile)
2 >> at net.c306.ttsuper.view.ui.MainActivity.c(SourceFile:1839)
at net.c306.ttsuper.view.ui.MainActivity.a(SourceFile:1993)
at net.c306.ttsuper.view.ui.MainActivity.a(SourceFile:1967)
at net.c306.ttsuper.view.ui.MainActivity.onCreate(SourceFile:386)
at android.app.Activity.performCreate(Activity.java:6251)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
标记为(1)的行是发生崩溃的ViewModel的惰性创建.
标记为(2)的行是对ViewModel的首次访问，该访问会启动延迟创建:
Line labeled (1) is the lazy create of ViewModel where the crash happens.
Line labeled (2) is the first access of ViewModel that initiates the lazy creation:
val lastState = searchStackViewModel.currentState()
推荐答案
我可能已经解决了这个问题.事实证明，在 lifecycle-2.0.0 中，ViewModel类具有公共方法 clear():
I have probably resolved this. Turns out that in lifecycle-2.0.0, the ViewModel class has a public method clear():
@MainThread
final void clear() {
mCleared = true;
// Since clear() is final, this method is still called on mock objects
// and in those cases, mBagOfTags is null. It'll always be empty though
// because setTagIfAbsent and getTag are not final so we can skip
// clearing it
if (mBagOfTags != null) {
synchronized (mBagOfTags) {
for (Object value : mBagOfTags.values()) {
// see comment for the similar call in setTagIfAbsent
closeWithRuntimeException(value);
}
}
}
onCleared();
}
我的 SearchStackViewModel 也有一个完全不相关的 clear()方法.
My SearchStackViewModel also has a completely unrelated clear() method.
/**
* Clear stack
*/
fun clear() {
val current = privateStack.value ?: SearchStack()
current.clear()
privateStack.value = current
}
打开 minifyEnabled 时，两者之间似乎存在冲突，因此出现了链接错误.我重命名了方法，然后崩溃停止了.
When minifyEnabled is on, there appears to be a conflict between the two, hence the Linkage error. I renamed my method and the crashes stopped.
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