我的应用程序在启动时崩溃,使用
lazy{}
创建视图模型时出现LinkageError
。只有在以下情况下才会崩溃:
build.gradle
中设置了minifyEnabled=true
,并且- 我使用生命周期组件的版本2.1.0。如果使用
lifecycle-2.0.0
和minifyEnabled
一起使用,则可以正常工作。
def lifecycle_version = '2.1.0'
implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:$lifecycle_version"
implementation "androidx.lifecycle:lifecycle-extensions:$lifecycle_version"
此外,崩溃只会在一个视图模型中发生。在这个视图模型之前被触碰的同一活动中的其他视图模型并不会导致应用程序崩溃。
崩溃发生在这里的第二行:
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:
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)
}
}
而 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
}
堆栈跟踪:
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)
标有(1)的行是ViewModel的惰性创建,在这里发生了崩溃。
标有(2)的行是ViewModel的第一次访问,它启动了惰性创建:
val lastState = searchStackViewModel.currentState()