我在spinner中有一个fragment。在onItemSelectedListener中设置onViewCreated会导致设备旋转后崩溃。
这是我的代码：
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
myspinner.onItemSelectedListener = object : AdapterView.OnItemSelectedListener {
override fun onItemSelected(parent: AdapterView<*>, view: View, position: Int, id: Long) {
Log.d("debug", "onSelectItem")
}
override fun onNothingSelected(parent: AdapterView<*>?) {}
}
val adapter = ArrayAdapter(activity, android.R.layout.simple_spinner_item, arrayOf(getString(R.string.mystring), getString(R.string.mystring1), getString(R.string.mystring2)))
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item)
myspinner.adapter = adapter
myspinner.setSelection(Values.selectedIndex)
}
我收到以下errors：
FATAL EXCEPTION: main
Process: myproject, PID: 12899
java.lang.IllegalArgumentException: Parameter specified as non-null is null: method kotlin.jvm.internal.Intrinsics.checkParameterIsNotNull, parameter view
at myproject.MyFragment$onViewCreated$1.onItemSelected(Unknown Source:45)
at android.widget.AdapterView.fireOnSelected(AdapterView.java:944)
at android.widget.AdapterView.dispatchOnItemSelected(AdapterView.java:933)
at android.widget.AdapterView.selectionChanged(AdapterView.java:922)
at android.widget.AdapterView.checkSelectionChanged(AdapterView.java:1105)
at android.widget.AdapterView.handleDataChanged(AdapterView.java:1081)
at android.widget.AbsSpinner.onMeasure(AbsSpinner.java:191)
at android.widget.Spinner.onMeasure(Spinner.java:602)
at android.support.v7.widget.AppCompatSpinner.onMeasure(AppCompatSpinner.java:420)
at android.view.View.measure(View.java:23169)
at android.support.constraint.ConstraintLayout.internalMeasureChildren(ConstraintLayout.java:1212)
at android.support.constraint.ConstraintLayout.onMeasure(ConstraintLayout.java:1552)
at android.view.View.measure(View.java:23169)
at android.support.constraint.ConstraintLayout.internalMeasureChildren(ConstraintLayout.java:1212)
at android.support.constraint.ConstraintLayout.onMeasure(ConstraintLayout.java:1552)
at android.view.View.measure(View.java:23169)
at android.support.v4.widget.NestedScrollView.measureChildWithMargins(NestedScrollView.java:1450)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
at android.support.v4.widget.NestedScrollView.onMeasure(NestedScrollView.java:516)
at android.view.View.measure(View.java:23169)
at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1632)
at android.view.View.measure(View.java:23169)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6749)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
at android.view.View.measure(View.java:23169)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6749)
at android.support.design.widget.CoordinatorLayout.onMeasureChild(CoordinatorLayout.java:739)
at android.support.design.widget.HeaderScrollingViewBehavior.onMeasureChild(HeaderScrollingViewBehavior.java:91)
at android.support.design.widget.AppBarLayout$ScrollingViewBehavior.onMeasureChild(AppBarLayout.java:1361)
at android.support.design.widget.CoordinatorLayout.onMeasure(CoordinatorLayout.java:809)
at android.view.View.measure(View.java:23169)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6749)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:141)
at android.view.View.measure(View.java:23169)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6749)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1535)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:825)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:704)
at android.view.View.measure(View.java:23169)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6749)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
at android.view.View.measure(View.java:23169)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6749)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1535)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:825)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:704)
at android.view.View.measure(View.java:23169)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6749)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
at com.android.internal.policy.DecorView.onMeasure(DecorView.java:716)
at android.view.View.measure(View.java:23169)
at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2719)
E/AndroidRuntime: at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1572)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1856)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1460)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:7184)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:949)
at android.view.Choreographer.doCallbacks(Choreographer.java:761)
at android.view.Choreographer.doFrame(Choreographer.java:696)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:935)
at android.os.Handler.handleCallback(Handler.java:873)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:6669)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
如果我将onItemSelectedListener注释掉，则它不会崩溃。