Android Studio DatePicker/TimePicker 渲染/nullpointerexception 问题？答案

【问题标题】：Android Studio DatePicker/TimePicker rendering/nullpointerexception problems?Android Studio DatePicker/TimePicker 渲染/nullpointerexception 问题？
【发布时间】：2015-02-08 00:45:45
【问题描述】：

日历视图之类的东西非常好用，但我不太确定为什么它找不到 DatePicker 或 TimePicker 所需的内容。

我对 Android 不太熟悉，如果这个问题太简单，请见谅。

构建 135.1629389

对于日期选择器：

android.content.res.Resources$NotFoundException
    at com.android.layoutlib.bridge.android.BridgeContext.obtainStyledAttributes(BridgeContext.java:484)
    at android.widget.TextView.setTextAppearance(TextView.java:2484)
    at android.widget.YearPickerView$YearAdapter.getView(YearPickerView.java:132)
    at android.widget.AbsListView.obtainView(AbsListView.java:2344)
    at android.widget.ListView.measureHeightOfChildren(ListView.java:1270)
    at android.widget.ListView.onMeasure(ListView.java:1182)
    at android.view.View.measure(View.java:17430)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463)
    at android.widget.FrameLayout.onMeasure(FrameLayout.java:430)
    at android.view.View.measure(View.java:17430)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463)
    at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1436)
    at android.widget.LinearLayout.measureVertical(LinearLayout.java:722)
    at android.widget.LinearLayout.onMeasure(LinearLayout.java:613)
    at android.view.View.measure(View.java:17430)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463)
    at android.widget.FrameLayout.onMeasure(FrameLayout.java:430)
    at android.view.View.measure(View.java:17430)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463)
    at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1436)
    at android.widget.LinearLayout.measureVertical(LinearLayout.java:722)
    at android.widget.LinearLayout.onMeasure(LinearLayout.java:613)
    at android.view.View.measure(View.java:17430)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463)
    at android.widget.FrameLayout.onMeasure(FrameLayout.java:430)
    at android.view.View.measure(View.java:17430)
    at android.widget.LinearLayout.measureVertical(LinearLayout.java:875)
    at android.widget.LinearLayout.onMeasure(LinearLayout.java:613)
    at android.view.View.measure(View.java:17430)
    at android.widget.LinearLayout.measureVertical(LinearLayout.java:875)
    at android.widget.LinearLayout.onMeasure(LinearLayout.java:613)
    at android.view.View.measure(View.java:17430)
    at com.android.layoutlib.bridge.impl.RenderSessionImpl.measureView(RenderSessionImpl.java:627)
    at com.android.layoutlib.bridge.impl.RenderSessionImpl.render(RenderSessionImpl.java:527)
    at com.android.layoutlib.bridge.Bridge.createSession(Bridge.java:331)
    at com.android.ide.common.rendering.LayoutLibrary.createSession(LayoutLibrary.java:350)
    at com.android.tools.idea.rendering.RenderService$5.compute(RenderService.java:688)
    at com.android.tools.idea.rendering.RenderService$5.compute(RenderService.java:677)
    at com.intellij.openapi.application.impl.ApplicationImpl.runReadAction(ApplicationImpl.java:932)
    at com.android.tools.idea.rendering.RenderService.createRenderSession(RenderService.java:677)
    at com.android.tools.idea.rendering.RenderService.render(RenderService.java:815)
    at com.intellij.android.designer.designSurface.AndroidDesignerEditorPanel$6.run(AndroidDesignerEditorPanel.java:480)
    at com.intellij.util.ui.update.MergingUpdateQueue.execute(MergingUpdateQueue.java:320)
    at com.intellij.util.ui.update.MergingUpdateQueue.execute(MergingUpdateQueue.java:310)
    at com.intellij.util.ui.update.MergingUpdateQueue$2.run(MergingUpdateQueue.java:254)
    at com.intellij.util.ui.update.MergingUpdateQueue.flush(MergingUpdateQueue.java:269)
    at com.intellij.util.ui.update.MergingUpdateQueue.flush(MergingUpdateQueue.java:227)
    at com.intellij.util.ui.update.MergingUpdateQueue.run(MergingUpdateQueue.java:217)
    at com.intellij.util.concurrency.QueueProcessor.runSafely(QueueProcessor.java:238)
    at com.intellij.util.Alarm$Request$1.run(Alarm.java:327)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:439)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
    at java.util.concurrent.FutureTask.run(FutureTask.java:138)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918)
    at java.lang.Thread.run(Thread.java:695)

时间选择器

java.lang.NullPointerException
    at android.hardware.input.InputManager.populateInputDevicesLocked(InputManager.java:691)
    at android.hardware.input.InputManager.getInputDevice(InputManager.java:204)
    at android.view.KeyCharacterMap.load(KeyCharacterMap.java:334)
    at android.widget.TimePickerSpinnerDelegate.getAmOrPmKeyCode(TimePickerSpinnerDelegate.java:1035)
    at android.widget.TimePickerSpinnerDelegate.generateLegalTimesTree(TimePickerSpinnerDelegate.java:1133)
    at android.widget.TimePickerSpinnerDelegate.<init>(TimePickerSpinnerDelegate.java:175)
    at android.widget.TimePicker.<init>(TimePicker.java:89)
    at android.widget.TimePicker.<init>(TimePicker.java:76)
    at android.widget.TimePicker.<init>(TimePicker.java:72)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
    at android.view.LayoutInflater.createView(LayoutInflater.java:607)
    at android.view.BridgeInflater.onCreateView(BridgeInflater.java:82)
    at android.view.LayoutInflater.onCreateView(LayoutInflater.java:682)
    at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:741)
    at android.view.BridgeInflater.createViewFromTag(BridgeInflater.java:128)
    at android.view.LayoutInflater.rInflate_Original(LayoutInflater.java:806)
    at android.view.LayoutInflater_Delegate.rInflate(LayoutInflater_Delegate.java:64)
    at android.view.LayoutInflater.rInflate(LayoutInflater.java:782)
    at android.view.LayoutInflater.inflate(LayoutInflater.java:504)
    at android.view.LayoutInflater.inflate(LayoutInflater.java:385)
    at com.android.layoutlib.bridge.impl.RenderSessionImpl.inflate(RenderSessionImpl.java:401)
    at com.android.layoutlib.bridge.Bridge.createSession(Bridge.java:329)
    at com.android.ide.common.rendering.LayoutLibrary.createSession(LayoutLibrary.java:350)
    at com.android.tools.idea.rendering.RenderService$5.compute(RenderService.java:688)
    at com.android.tools.idea.rendering.RenderService$5.compute(RenderService.java:677)
    at com.intellij.openapi.application.impl.ApplicationImpl.runReadAction(ApplicationImpl.java:932)
    at com.android.tools.idea.rendering.RenderService.createRenderSession(RenderService.java:677)
    at com.android.tools.idea.rendering.RenderService.render(RenderService.java:815)
    at com.intellij.android.designer.designSurface.AndroidDesignerEditorPanel$6.run(AndroidDesignerEditorPanel.java:480)
    at com.intellij.util.ui.update.MergingUpdateQueue.execute(MergingUpdateQueue.java:320)
    at com.intellij.util.ui.update.MergingUpdateQueue.execute(MergingUpdateQueue.java:310)
    at com.intellij.util.ui.update.MergingUpdateQueue$2.run(MergingUpdateQueue.java:254)
    at com.intellij.util.ui.update.MergingUpdateQueue.flush(MergingUpdateQueue.java:269)
    at com.intellij.util.ui.update.MergingUpdateQueue.flush(MergingUpdateQueue.java:227)
    at com.intellij.util.ui.update.MergingUpdateQueue.run(MergingUpdateQueue.java:217)
    at com.intellij.util.concurrency.QueueProcessor.runSafely(QueueProcessor.java:238)
    at com.intellij.util.Alarm$Request$1.run(Alarm.java:327)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:439)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
    at java.util.concurrent.FutureTask.run(FutureTask.java:138)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918)
    at java.lang.Thread.run(Thread.java:695)

【问题讨论】：

见code.google.com/p/android/issues/detail?id=78842
嗯，我只是在手机上运行该应用程序，然后显示 DatePicker。我认为解决方案是这样的，但适用于 Android Studio 而不是 Eclipse：stackoverflow.com/questions/11365959/…
好吧，我不得不降级 API 版本才能在“设计”选项卡中显示。我下载了 API 19 并将“在 IDE 中渲染布局时使用的 Android 布局”更改为 API 19。我认为 API 21 存在错误

标签： java datepicker android-studio timepicker

【解决方案1】：

对于那些遇到相同问题的人，例如Android Studio 和 API 21，尝试设置android:datePickerMode。除了这条线，没有任何效果。请注意，它是 API 21 的新功能。

【讨论】：

【解决方案2】：

此外，API21 似乎存在一个专门针对日期/时间选择器的渲染错误，而且对于一些修订版来说，这似乎是一个持续存在的问题。正如您在上面所说的，回落到 19 或更少可以解决它。 20我没试过。

见：https://code.google.com/p/android/issues/detail?id=82712

【讨论】：