对于android–获取截图时出现意外错误–java.lang.nullpointerexception感兴趣的读者，本文将提供您所需要的所有信息，我们将详细讲解java.lang.NullPoint

对于android – 获取截图时出现意外错误 – java.lang.nullpointerexception感兴趣的读者，本文将提供您所需要的所有信息，我们将详细讲解java.lang.NullPointerException翻译，并且为您提供关于Android AVD Manager：无法创建新的设备定义(java.lang.NullPointerException)、Android java.lang.RuntimeException：无法实例化活动ComponentInfo … java.lang.NullPointerException、Android sdk：java.lang.NullPointerException：尝试调用虚方法、Android XML文件java.lang.nullpointerexception的宝贵知识。

• android – 获取截图时出现意外错误 – java.lang.nullpointerexception（java.lang.NullPointerException翻译）
• Android AVD Manager：无法创建新的设备定义(java.lang.NullPointerException)
• Android java.lang.RuntimeException：无法实例化活动ComponentInfo … java.lang.NullPointerException
• Android sdk：java.lang.NullPointerException：尝试调用虚方法
• Android XML文件java.lang.nullpointerexception

android – 获取截图时出现意外错误 – java.lang.nullpointerexception（java.lang.NullPointerException翻译）

我在Android Studio 2.0中捕获屏幕截图时遇到错误.我尝试使用2种不同的平板电脑,并且我们都遇到了这个错误.

Unexpected Error while obtaining screenshot - java.lang.Nullpointerexception

我google了,并查看了不同的stackoverflow问题,但没有发现任何可以解决此问题.

我最近安装了Android Studio 2.0,这可能是我不知道的问题.

解决方法:

这是一个古老的问题,但还有另一个具体原因,为什么会发生这种情况,虽然显然不是OP的情况,但它可能仍然可以帮助其他人：

如果你有getActivity().getwindow().addFlags(LayoutParams.FLAG_SECURE);设置(通常用于避免截图),它还会阻止您从Android Studio截取屏幕截图,在获取屏幕截图时生成相同的错误意外错误.

Android AVD Manager：无法创建新的设备定义(java.lang.NullPointerException)

java.lang.NullPointerException
    at com.android.sdkuilib.internal.widgets.DeviceCreationDialog.okpressed(DeviceCreationDialog.java:916)
    at org.eclipse.jface.dialogs.Dialog.buttonpressed(Dialog.java:472)
    at org.eclipse.jface.dialogs.Dialog$2.widgetSelected(Dialog.java:624)
    at org.eclipse.swt.widgets.TypedListener.handleEvent(UnkNown Source)
    at org.eclipse.swt.widgets.EventTable.sendEvent(UnkNown Source)
    at org.eclipse.swt.widgets.display.sendEvent(UnkNown Source)
    at org.eclipse.swt.widgets.Widget.sendEvent(UnkNown Source)
    at org.eclipse.swt.widgets.Widget.sendEvent(UnkNown Source)
    at org.eclipse.swt.widgets.Widget.sendEvent(UnkNown Source)
    at org.eclipse.swt.widgets.Widget.notifyListeners(UnkNown Source)
    at org.eclipse.swt.widgets.display.runDeferredEvents(UnkNown Source)
    at org.eclipse.swt.widgets.display.readAnddispatch(UnkNown Source)
    at org.eclipse.jface.window.Window.runEventLoop(Window.java:825)
    at org.eclipse.jface.window.Window.open(Window.java:801)
    at com.android.sdkuilib.internal.repository.ui.DeviceManagerPage.onNewDevice(DeviceManagerPage.java:658)
    at com.android.sdkuilib.internal.repository.ui.DeviceManagerPage.access$100(DeviceManagerPage.java:97)
    at com.android.sdkuilib.internal.repository.ui.DeviceManagerPage$3.widgetSelected(DeviceManagerPage.java:215)
    at org.eclipse.swt.widgets.TypedListener.handleEvent(UnkNown Source)
    at org.eclipse.swt.widgets.EventTable.sendEvent(UnkNown Source)
    at org.eclipse.swt.widgets.display.sendEvent(UnkNown Source)
    at org.eclipse.swt.widgets.Widget.sendEvent(UnkNown Source)
    at org.eclipse.swt.widgets.Widget.sendEvent(UnkNown Source)
    at org.eclipse.swt.widgets.Widget.sendEvent(UnkNown Source)
    at org.eclipse.swt.widgets.Widget.notifyListeners(UnkNown Source)
    at org.eclipse.swt.widgets.display.runDeferredEvents(UnkNown Source)
    at org.eclipse.swt.widgets.display.readAnddispatch(UnkNown Source)
    at com.android.sdkuilib.internal.repository.ui.AvdManagerWindowImpl1.open(AvdManagerWindowImpl1.java:146)
    at com.android.sdkuilib.repository.AvdManagerWindow.open(AvdManagerWindow.java:94)
    at com.android.sdkmanager.Main.showAvdManagerWindow(Main.java:437)
    at com.android.sdkmanager.Main.doAction(Main.java:379)
    at com.android.sdkmanager.Main.run(Main.java:150)
    at com.android.sdkmanager.Main.main(Main.java:116)

Android java.lang.RuntimeException：无法实例化活动ComponentInfo … java.lang.NullPointerException

出于某种原因,每次尝试启动我的应用程序时,我都会出现以下错误：

Unable to instantiate activity ComponentInfo{com.example.lifeahead/com.example.lifeahead.MainActivity}:java.lang.NullPointerException

我检查了清单文件,并添加了所有活动.

我启动应用程序时使用的唯一方法是：

private void logIn(){
    Button logIn = (Button) findViewById(R.id.login);
    logIn.setonClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // Todo Auto-generated method stub
            Intent loginIntent = new Intent(MainActivity.this, HomeActivity.class);
            loginIntent.putExtra("cmUN", cmUN);
            loginIntent.putExtra("cmPW", cmPW);
            startActivity(loginIntent);
        }
    });
}

这是onCreate：

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    if (savedInstanceState == null) {
        getSupportFragmentManager().beginTransaction()
                .add(R.id.container, new PlaceholderFragment()).commit();
    }

    logIn();
}

完整日志：

Ë

/AndroidRuntime(1607): FATAL EXCEPTION: main
E/AndroidRuntime(1607): Process: com.example.lifeahead, PID: 1607
E/AndroidRuntime(1607): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.lifeahead/com.example.lifeahead.MainActivity}: java.lang.NullPointerException
E/AndroidRuntime(1607):     at android.app.ActivityThread.performlaunchActivity(ActivityThread.java:2121)
E/AndroidRuntime(1607):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
E/AndroidRuntime(1607):     at android.app.ActivityThread.access$800(ActivityThread.java:135)
E/AndroidRuntime(1607):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
E/AndroidRuntime(1607):     at android.os.Handler.dispatchMessage(Handler.java:102)
E/AndroidRuntime(1607):     at android.os.Looper.loop(Looper.java:136)
E/AndroidRuntime(1607):     at android.app.ActivityThread.main(ActivityThread.java:5017)
E/AndroidRuntime(1607):     at java.lang.reflect.Method.invokeNative(Native Method)
E/AndroidRuntime(1607):     at java.lang.reflect.Method.invoke(Method.java:515)
E/AndroidRuntime(1607):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
E/AndroidRuntime(1607):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
E/AndroidRuntime(1607):     at dalvik.system.NativeStart.main(Native Method)
E/AndroidRuntime(1607): Caused by: java.lang.NullPointerException
E/AndroidRuntime(1607):     at android.app.Activity.findViewById(Activity.java:1884)
E/AndroidRuntime(1607):     at com.example.lifeahead.MainActivity.<init>(MainActivity.java:22)
E/AndroidRuntime(1607):     at java.lang.class.newInstanceImpl(Native Method)
E/AndroidRuntime(1607):     at java.lang.class.newInstance(Class.java:1208)
E/AndroidRuntime(1607):     at android.app.Instrumentation.newActivity(Instrumentation.java:1061)
E/AndroidRuntime(1607):     at android.app.ActivityThread.performlaunchActivity(ActivityThread.java:2112)
E/AndroidRuntime(1607):     ... 11 more

我感谢所有帮助！

解决方法:

stacktrace告诉你

  Button logIn = (Button) findViewById(R.id.login);

findViewById返回的对象为null,因为您拥有的唯一方法是logIn(). findViewById返回null的唯一原因是因为您正在查找不属于当前活动的视图层次结构的视图

Android sdk：java.lang.NullPointerException：尝试调用虚方法

07-05 22:45:02.550    2821-2821/davvarn.csgo_maps E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: davvarn.csgo_maps,PID: 2821
    java.lang.RuntimeException: Unable to start activity ComponentInfo{davvarn.csgo_maps/davvarn.csgo_maps.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ImageView.setimageDrawable(android.graphics.drawable.Drawable)' on a null object reference
            at android.app.ActivityThread.performlaunchActivity(ActivityThread.java:2356)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2418)
            at android.app.ActivityThread.access$900(ActivityThread.java:154)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1321)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5289)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:904)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:699)
     Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ImageView.setimageDrawable(android.graphics.drawable.Drawable)' on a null object reference
            at davvarn.csgo_maps.MainActivity.changeContent(MainActivity.java:176)
            at davvarn.csgo_maps.MainActivity.onCreate(MainActivity.java:115)
            at android.app.Activity.performCreate(Activity.java:5990)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106)
            at android.app.ActivityThread.performlaunchActivity(ActivityThread.java:2309)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2418)
at android.app.ActivityThread.access$900(ActivityThread.java:154)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1321)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5289)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:904)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:699)

Android XML文件java.lang.nullpointerexception

我正在建立一个全新的android项目。这不是我的第一个android应用程序，所以我更沮丧的是无法摆脱此错误…

我使用的XML文件目前只有3个项目，并且XML标签中没有错误：

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:id="@+id/container"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context=".gaming..MainActivity" >    <ImageView        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:background="@drawable/fondipad"        android:contentDescription="@string/FondDesc"        />    <RelativeLayout         android:layout_height="300dp"         android:layout_width="fill_parent"        android:background="@drawable/cadremenu">    </RelativeLayout>     </RelativeLayout>

很简单，是吗？但是，视觉选项卡不会使cadremenu可绘制（但“喜欢”会呈现）…但是cadremenu.png在drawable文件夹中！我可以启动应用程序，但只渲染背景…我真的不知道该怎么办…
xml文件返回此异常

java.lang.NullPointerException    at android.graphics.Bitmap_Delegate.createBitmap(Bitmap_Delegate.java:598)    at android.graphics.Bitmap_Delegate.createBitmap(Bitmap_Delegate.java:120)    at android.graphics.Bitmap_Delegate.createBitmap(Bitmap_Delegate.java:102)    at com.android.layoutlib.bridge.impl.ResourceHelper.getDrawable(ResourceHelper.java:233)    at android.content.res.BridgeTypedArray.getDrawable(BridgeTypedArray.java:782)    at android.view.View.<init>(View.java:3554)    at android.view.View.<init>(View.java:3484)    at android.view.ViewGroup.<init>(ViewGroup.java:464)    at android.widget.RelativeLayout.<init>(RelativeLayout.java:236)    at sun.reflect.GeneratedConstructorAccessor37.newInstance(Unknown Source)    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)    at java.lang.reflect.Constructor.newInstance(Constructor.java:513)    at android.view.LayoutInflater.createView(LayoutInflater.java:594)    at android.view.BridgeInflater.onCreateView(BridgeInflater.java:86)    at android.view.LayoutInflater.onCreateView(LayoutInflater.java:669)    at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:694)    at android.view.BridgeInflater.createViewFromTag(BridgeInflater.java:131)    at android.view.LayoutInflater.rInflate_Original(LayoutInflater.java:755)    at android.view.LayoutInflater_Delegate.rInflate(LayoutInflater_Delegate.java:64)    at android.view.LayoutInflater.rInflate(LayoutInflater.java:727)    at android.view.LayoutInflater.inflate(LayoutInflater.java:492)    at android.view.LayoutInflater.inflate(LayoutInflater.java:373)    at com.android.layoutlib.bridge.impl.RenderSessionImpl.inflate(RenderSessionImpl.java:399)    at com.android.layoutlib.bridge.Bridge.createSession(Bridge.java:336)    at com.android.ide.common.rendering.LayoutLibrary.createSession(LayoutLibrary.java:332)    at com.android.ide.eclipse.adt.internal.editors.layout.gle2.RenderService.createRenderSession(RenderService.java:504)    at com.android.ide.eclipse.adt.internal.editors.layout.gle2.GraphicalEditorPart.renderWithBridge(GraphicalEditorPart.java:1584)    at com.android.ide.eclipse.adt.internal.editors.layout.gle2.GraphicalEditorPart.recomputeLayout(GraphicalEditorPart.java:1309)    at com.android.ide.eclipse.adt.internal.editors.layout.gle2.GraphicalEditorPart.activated(GraphicalEditorPart.java:1066)    at com.android.ide.eclipse.adt.internal.editors.layout.LayoutEditorDelegate.delegatePageChange(LayoutEditorDelegate.java:686)    at com.android.ide.eclipse.adt.internal.editors.common.CommonXmlEditor.pageChange(CommonXmlEditor.java:360)    at org.eclipse.ui.part.MultiPageEditorPart$2.widgetSelected(MultiPageEditorPart.java:292)    at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:248)    at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)    at org.eclipse.swt.widgets.Display.sendEvent(Display.java:4136)    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1458)    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1481)    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1466)    at org.eclipse.swt.widgets.Widget.notifyListeners(Widget.java:1271)    at org.eclipse.swt.custom.CTabFolder.setSelection(CTabFolder.java:3028)    at org.eclipse.swt.custom.CTabFolder.onMouse(CTabFolder.java:1749)    at org.eclipse.swt.custom.CTabFolder$1.handleEvent(CTabFolder.java:278)    at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)    at org.eclipse.swt.widgets.Display.sendEvent(Display.java:4136)    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1458)    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1481)    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1466)    at org.eclipse.swt.widgets.Widget.notifyListeners(Widget.java:1271)    at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3982)    at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3621)    at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$9.run(PartRenderingEngine.java:1053)    at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)    at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:942)    at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:86)    at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:588)    at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)    at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:543)    at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)    at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:124)    at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)    at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)    at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:353)    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:180)    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)    at java.lang.reflect.Method.invoke(Method.java:597)    at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:629)    at org.eclipse.equinox.launcher.Main.basicRun(Main.java:584)    at org.eclipse.equinox.launcher.Main.run(Main.java:1438)

任何帮助都将受到欢迎！

编辑：我已经尝试过删除，放回可绘制对象，项目，…。清理项目，重新构建…我什至尝试删除并重新安装每个ADT组件

答案1

正如@laato所建议的，我检查了我的drawable /
cadremenu文件。我在项目中复制/粘贴/覆盖了文件，然后一切正常！实际上，我所有其他资源都有相同的问题，例如我的资源文件夹已损坏或类似问题。

谢谢大家，希望有一天有人能在这里找到帮助

我们今天的关于android – 获取截图时出现意外错误 – java.lang.nullpointerexception和java.lang.NullPointerException翻译的分享就到这里，谢谢您的阅读，如果想了解更多关于Android AVD Manager：无法创建新的设备定义(java.lang.NullPointerException)、Android java.lang.RuntimeException：无法实例化活动ComponentInfo … java.lang.NullPointerException、Android sdk：java.lang.NullPointerException：尝试调用虚方法、Android XML文件java.lang.nullpointerexception的相关信息，可以在本站进行搜索。