NullPointerException異常ContextCompat錯誤

我已經創建了一個自定義組件，其上增加了佈局，我收到以下錯誤NullPointerException異常ContextCompat錯誤

錯誤如下

java.lang.NullPointerException 
    at android.support.v4.content.ContextCompatApi21.getDrawable(ContextCompatApi21.java:26) 
    at android.support.v4.content.ContextCompat.getDrawable(ContextCompat.java:321) 
    at com.test.digitalexperience.widget.testTicketLoaderWidget.createDrawables(testTicketLoaderWidget.java:101) 
    at com.test.digitalexperience.widget.testTicketLoaderWidget.init(testTicketLoaderWidget.java:69) 
    at com.test.digitalexperience.widget.testTicketLoaderWidget.<init>(testTicketLoaderWidget.java:52) 
    at com.test.digitalexperience.widget.testTicketLoaderWidget.<init>(testTicketLoaderWidget.java:44) 
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) 
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57) 
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) 
    at java.lang.reflect.Constructor.newInstance(Constructor.java:526) 
    at org.jetbrains.android.uipreview.ViewLoader.createNewInstance(ViewLoader.java:465) 
    at org.jetbrains.android.uipreview.ViewLoader.loadClass(ViewLoader.java:172) 
    at org.jetbrains.android.uipreview.ViewLoader.loadView(ViewLoader.java:105) 
    at com.android.tools.idea.rendering.LayoutlibCallbackImpl.loadView(LayoutlibCallbackImpl.java:170) 
    at android.view.BridgeInflater.loadCustomView(BridgeInflater.java:247) 
    at android.view.BridgeInflater.createViewFromTag(BridgeInflater.java:171) 
    at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:704) 
    at android.view.LayoutInflater.rInflate_Original(LayoutInflater.java:835) 
    at android.view.LayoutInflater_Delegate.rInflate(LayoutInflater_Delegate.java:70) 
    at android.view.LayoutInflater.rInflate(LayoutInflater.java:811) 
    at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:798) 
    at android.view.LayoutInflater.inflate(LayoutInflater.java:515) 
    at android.view.LayoutInflater.inflate(LayoutInflater.java:394) 
    at com.android.layoutlib.bridge.impl.RenderSessionImpl.inflate(RenderSessionImpl.java:223) 
    at com.android.layoutlib.bridge.Bridge.createSession(Bridge.java:426) 
    at com.android.ide.common.rendering.LayoutLibrary.createSession(LayoutLibrary.java:350) 
    at com.android.tools.idea.rendering.RenderTask$2.compute(RenderTask.java:510) 
    at com.android.tools.idea.rendering.RenderTask$2.compute(RenderTask.java:498) 
    at com.intellij.openapi.application.impl.ApplicationImpl.runReadAction(ApplicationImpl.java:967) 
    at com.android.tools.idea.rendering.RenderTask.createRenderSession(RenderTask.java:498) 
    at com.android.tools.idea.rendering.RenderTask.access$600(RenderTask.java:72) 
    at com.android.tools.idea.rendering.RenderTask$3.call(RenderTask.java:610) 
    at com.android.tools.idea.rendering.RenderTask$3.call(RenderTask.java:607) 
    at com.android.tools.idea.rendering.RenderService.runRenderAction(RenderService.java:359) 
    at com.android.tools.idea.rendering.RenderTask.render(RenderTask.java:607) 
    at com.android.tools.idea.rendering.RenderTask.render(RenderTask.java:629) 
    at org.jetbrains.android.uipreview.AndroidLayoutPreviewToolWindowManager.doRender(AndroidLayoutPreviewToolWindowManager.java:652) 
    at org.jetbrains.android.uipreview.AndroidLayoutPreviewToolWindowManager.access$1700(AndroidLayoutPreviewToolWindowManager.java:80) 
    at org.jetbrains.android.uipreview.AndroidLayoutPreviewToolWindowManager$7$1.run(AndroidLayoutPreviewToolWindowManager.java:594) 
    at com.intellij.openapi.progress.impl.CoreProgressManager$2.run(CoreProgressManager.java:142) 
    at com.intellij.openapi.progress.impl.CoreProgressManager.registerIndicatorAndRun(CoreProgressManager.java:446) 
    at com.intellij.openapi.progress.impl.CoreProgressManager.executeProcessUnderProgress(CoreProgressManager.java:392) 
    at com.intellij.openapi.progress.impl.ProgressManagerImpl.executeProcessUnderProgress(ProgressManagerImpl.java:54) 
    at com.intellij.openapi.progress.impl.CoreProgressManager.runProcess(CoreProgressManager.java:127) 
    at org.jetbrains.android.uipreview.AndroidLayoutPreviewToolWindowManager$7.run(AndroidLayoutPreviewToolWindowManager.java:589) 
    at com.intellij.util.ui.update.MergingUpdateQueue.execute(MergingUpdateQueue.java:337) 
    at com.intellij.util.ui.update.MergingUpdateQueue.execute(MergingUpdateQueue.java:327) 
    at com.intellij.util.ui.update.MergingUpdateQueue$3.run(MergingUpdateQueue.java:271) 
    at com.intellij.util.ui.update.MergingUpdateQueue.flush(MergingUpdateQueue.java:286) 
    at com.intellij.util.ui.update.MergingUpdateQueue.flush(MergingUpdateQueue.java:244) 
    at com.intellij.util.ui.update.MergingUpdateQueue.run(MergingUpdateQueue.java:234) 
    at com.intellij.util.concurrency.QueueProcessor.runSafely(QueueProcessor.java:238) 
    at com.intellij.util.Alarm$Request$1.run(Alarm.java:352) 
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471) 
    at java.util.concurrent.FutureTask.run(FutureTask.java:262) 
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) 
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) 
    at java.lang.Thread.run(Thread.java:745)

在我的Java類，我已經導入

android.support.v4.content.ContextCompat;

我在其中添加了

dependencies { 
    compile 'com.android.support:appcompat-v7:23.1.0'  
}

，我使用gradle這個版本

com.android.tools.build:gradle:2.0.0

自定義組件部件代碼

http://pastebin.com/nWn46qA3

來源

2016-04-21 ViVekH

包含有問題的代碼 – USKMobility

我認爲問題出在Drawable ID，它不會爲API> 21生成或引用錯誤。 –

更新的問題與代碼 – ViVekH

你叫init(Context context, AttributeSet attributeSet)方法，構造器初始化mContext之前。

來源

2016-04-21 05:01:52 shobhan

有相同的想法。 – FlanschiFox

謝謝你，我不好，我調試和檢查現在即時獲取上下文，在它爲空之前，但錯誤仍然存在 – ViVekH

尚未解決？ – shobhan

NullPointerException異常ContextCompat錯誤

回答

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