我有一个很大的问题,我想在我的 Android应用程序中集成admob但我在图形布局中得到一个nullpointer异常当我尝试将admob集成到xml文件中时

java.lang.NullPointerException
    at com.google.ads.AdView.onMeasure(SourceFile:670)
    at android.view.View.measure(View.java:15172)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4814)
    at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1390)
    at android.widget.LinearLayout.measureVertical(LinearLayout.java:681)
    at android.widget.LinearLayout.onMeasure(LinearLayout.java:574)
    at android.view.View.measure(View.java:15172)
    at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:617)
    at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:399)
    at android.view.View.measure(View.java:15172)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4814)
    at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
    at android.view.View.measure(View.java:15172)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4814)
    at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1390)
    at android.widget.LinearLayout.measureVertical(LinearLayout.java:681)
    at android.widget.LinearLayout.onMeasure(LinearLayout.java:574)
    at android.view.View.measure(View.java:15172)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4814)
    at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1390)
    at android.widget.LinearLayout.measureVertical(LinearLayout.java:681)
    at android.widget.LinearLayout.onMeasure(LinearLayout.java:574)
    at android.view.View.measure(View.java:15172)
    at com.android.layoutlib.bridge.impl.RenderSessionImpl.measureView(RenderSessionImpl.java:542)
    at com.android.layoutlib.bridge.impl.RenderSessionImpl.render(RenderSessionImpl.java:444)
    at com.android.layoutlib.bridge.Bridge.createSession(Bridge.java:333)
    at com.android.ide.common.rendering.LayoutLibrary.createSession(LayoutLibrary.java:325)
    at com.android.ide.eclipse.adt.internal.editors.layout.gle2.RenderService.createRenderSession(RenderService.java:372)
    at com.android.ide.eclipse.adt.internal.editors.layout.gle2.GraphicalEditorPart.renderWithBridge(GraphicalEditorPart.java:1638)
    at com.android.ide.eclipse.adt.internal.editors.layout.gle2.GraphicalEditorPart.recomputeLayout(GraphicalEditorPart.java:1389)
    at com.android.ide.eclipse.adt.internal.editors.layout.gle2.GraphicalEditorPart.activated(GraphicalEditorPart.java:1163)
    at com.android.ide.eclipse.adt.internal.editors.layout.LayoutEditorDelegate.delegatePageChange(LayoutEditorDelegate.java:674)
    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.Widget.sendEvent(Widget.java:1053)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1077)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1062)
    at org.eclipse.swt.widgets.Widget.notifyListeners(Widget.java:774)
    at org.eclipse.swt.custom.CTabFolder.setSelection(CTabFolder.java:3023)
    at org.eclipse.swt.custom.CTabFolder.onMouse(CTabFolder.java:1730)
    at org.eclipse.swt.custom.CTabFolder$1.handleEvent(CTabFolder.java:270)
    at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1053)
    at org.eclipse.swt.widgets.display.runDeferredEvents(display.java:4169)
    at org.eclipse.swt.widgets.display.readAnddispatch(display.java:3758)
    at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$9.run(PartRenderingEngine.java:1022)
    at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
    at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:916)
    at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:86)
    at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:585)
    at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
    at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:540)
    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(UnkNown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(UnkNown Source)
    at java.lang.reflect.Method.invoke(UnkNown Source)
    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)
    at org.eclipse.equinox.launcher.Main.main(Main.java:1414)

这是xml文件

<RelativeLayout xmlns:tools="http://schemas.android.com/tools"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/backgroundapp"
android:orientation="vertical" >



<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_alignParentBottom="true"
  android:orientation="vertical"
  android:gravity="bottom"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent">

    <ListView android:id="@id/android:list"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:cacheColorHint="#00000000"
    android:textColor="#FFFFFF"/>

    <Button
    android:id="@+id/add_main_btn"
    android:layout_width="fill_parent"
    android:layout_height="match_parent"
    android:text="@string/add_serie" />

</LinearLayout>



<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:ads="http://schemas.android.com/apk/lib/com.google.ads" android:layout_alignParentTop="true" android:id="@+id/ad_layout" android:orientation="vertical" android:gravity="top" android:layout_width="fill_parent" android:layout_height="fill_parent">

    <com.google.ads.AdView android:id="@+id/adView" android:layout_width="wrap_content" android:layout_height="wrap_content" ads:adUnitId="a15086a2a707a22" ads:adSize="BANNER" ads:loadAdOnCreate="true" />

</LinearLayout>

</RelativeLayout>

在这里我的课

adView = new AdView(this,AdSize.BANNER,MY_AD_UNIT_ID);
    LinearLayout layout = (LinearLayout)findViewById(R.id.adView);
    layout.addView(adView);
    adView.loadAd(new AdRequest());

谢谢你的回复.

编辑：添加其他XML布局文件相同的错误

<RelativeLayout 
xmlns:tools="http://schemas.android.com/tools"
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:ads="http://schemas.android.com/apk/lib/com.google.ads"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/backgroundapp"
android:orientation="vertical">

    <Button
        android:id="@+id/add_main_btn"
        android:layout_width="fill_parent"
        android:layout_height="70dp"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true"
        android:text="@string/add_serie" />

    <ListView
        android:id="@id/android:list"
        android:layout_width="fill_parent"
        android:layout_height="541dp"
        android:layout_alignParentLeft="true"
        android:cacheColorHint="#00000000"
        android:textColor="#FFFFFF" >

    </ListView>

    <com.google.ads.AdView 
    android:id="@+id/adView" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    ads:adUnitId="a15086a2a707a22" 
    ads:adSize="BANNER" 
    ads:testDevices="TEST_EMULATOR"
    ads:loadAdOnCreate="true" />

EDIT2：
问题解决Admob 6.2.1有一个Android 4.1.2的错误,将Api布局设置为10或更低,有新的错误消息但不影响程序或广告

查看AdView时onMeasure中的NullPointerException图形布局是一个已知问题.它将在下一个主要版本中修复.

与此同时,编辑原始XML或在代码中定义AdView也可以.

我是 android新手,我正在关注Material Design Toolbar的以下教程：

http://www.android4devs.com/2014/12/how-to-make-material-design-app.html

但是在执行代码之后. logcat中显示以下错误：

04-01 19:16:10.214    2246-2253/com.example.bhaskar.ddit_results E/art﹕ Failed sending reply to debugger: broken pipe
04-01 19:16:11.985    2246-2246/com.example.bhaskar.ddit_results E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.example.bhaskar.ddit_results,PID: 2246
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.bhaskar.ddit_results/com.example.bhaskar.ddit_results.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.CharSequence android.support.v7.widget.Toolbar.getTitle()' on a null object reference
        at android.app.ActivityThread.performlaunchActivity(ActivityThread.java:2298)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
        at android.app.ActivityThread.access$800(ActivityThread.java:144)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
        at android.os.Handler.dispatchMessage(Handler.java:102)
        at android.os.Looper.loop(Looper.java:135)
        at android.app.ActivityThread.main(ActivityThread.java:5221)
        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:899)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
 Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.CharSequence android.support.v7.widget.Toolbar.getTitle()' on a null object reference
        at android.support.v7.internal.widget.ToolbarWidgetWrapper.<init>(ToolbarWidgetWrapper.java:95)
        at android.support.v7.internal.widget.ToolbarWidgetWrapper.<init>(ToolbarWidgetWrapper.java:88)
        at android.support.v7.internal.app.ToolbaractionBar.<init>(ToolbaractionBar.java:84)
        at android.support.v7.app.ActionBaractivityDelegateBase.setSupportActionBar(ActionBaractivityDelegateBase.java:175)
        at android.support.v7.app.ActionBaractivity.setSupportActionBar(ActionBaractivity.java:92)
        at com.example.bhaskar.ddit_results.MainActivity.onCreate(MainActivity.java:41)
        at android.app.Activity.performCreate(Activity.java:5933)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
        at android.app.ActivityThread.performlaunchActivity(ActivityThread.java:2251)   
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)    
        at android.app.ActivityThread.access$800(ActivityThread.java:144)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
        at android.os.Handler.dispatchMessage(Handler.java:102)
        at android.os.Looper.loop(Looper.java:135)
        at android.app.ActivityThread.main(ActivityThread.java:5221)
        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:899)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)

这是由NullPointerException引起的.我正在使用Android Studio 1.0.1.

styles.xml：

<resources>

<!-- Base application theme. -->
<style name="MyTheme" parent="MyTheme.Base">

</style>

<style name="MyTheme.Base" parent="Theme.AppCompat.Light.NoActionBar">

    <item name="colorPrimary">#ff32cd32</item>
    <item name="colorPrimaryDark">#ff04cd2c</item>
    <item name="colorAccent">#ff4081</item>
</style>

V21 / styles.xml：

<resources>
<style name="MyTheme" parent="MyTheme.Base">
    <item name="android:windowContentTransitions">true</item>
    <item name="android:windowAllowEnterTransitionOverlap">true</item>
    <item name="android:windowAllowReturnTransitionOverlap">true</item>
    <item name="android:windowSharedElementEnterTransition">@android:transition/move</item>
    <item name="android:windowSharedElementExitTransition">@android:transition/move</item>

在toolbar.xml中我有：

<android.support.v7.widget.Toolbar xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="?attr/colorPrimary"
app:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
android:elevation="4dp"/>

我还在activity_main.xml文件中包含了工具栏布局.
在MainActivity.java中：

public class MainActivity extends ActionBaractivity {

....



private Toolbar toolbar;
public static final int RECORD_ENTRY_REQUEST_CODE=3;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    // Set our view from the "main" layout resource

     toolbar = (Toolbar)findViewById(R.id.toolbar);

    //Toolbar will Now take on default actionbar characteristics
    setContentView(R.layout.activity_main);
    setSupportActionBar(toolbar);
    setTitle("DDIT_Results");
    ....

}

我搜索了这个问题并且没有提出任何解决方案.希望有人认识到这个错误并且有一个快速的答案 – 否则我可以提供更多的信息,如果要求.任何帮助将是appriciated.

您需要在添加任何视图(如工具栏)之前调用setContentView.

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);         // <-- call this first

    toolbar = (Toolbar) findViewById(R.id.toolbar); // <-- setup views after

    setSupportActionBar(toolbar);
    setTitle("DDIT_Results");
}

请参阅官方Android开发者博客：http://android-developers.blogspot.com/2014/10/appcompat-v21-material-design-for-pre.html

行动吧

To use Toolbar as an Action Bar,first disable the decor-provided
Action Bar. The easiest way is to have your theme extend from
Theme.AppCompat.NoActionBar (or its light variant).

Second,create a Toolbar instance,usually via your layout XML:

<android.support.v7.widget.Toolbar
    android:id=”@+id/my_awesome_toolbar”
    android:layout_height=”wrap_content”
    android:layout_width=”match_parent”
    android:minHeight=”?attr/actionBarSize”
    android:background=”?attr/colorPrimary” />

The height,width,background,and so on are totally up to you; these
are just good examples. As Toolbar is just a ViewGroup,you can style
and position it however you want.

Then in your Activity or Fragment,set the Toolbar to act as your
Action Bar:

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.blah);

    final Toolbar toolbar = (Toolbar) findViewById(R.id.my_awesome_toolbar);
    setSupportActionBar(toolbar);
}

From this point on,all menu items are displayed in your Toolbar,populated via the standard options menu callbacks.

我正在尝试设置FragmentStatePagerAdapter,在我的一个类似于 this example的片段上创建一个可滚动的标签界面.在我的活动的onCreate中：

@Override
 public void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     setContentView(R.layout.base);

     setVersionString();
     setupActionBar();
     setupNavigationDrawer();
     setupFragments();
}

我将内容视图设置为以下布局(R.layout.base)：

<android.support.v4.widget.DrawerLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/drawer_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".BaseActivity" >

    <!-- The main content view -->
    <FrameLayout
        android:id="@+id/main_frame"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <!-- The navigation drawer -->
    <ListView
        android:id="@+id/nav_drawer"
        android:layout_width="240dp"
        android:layout_height="match_parent"
        android:layout_gravity="start"
        android:choiceMode="singleChoice"
        android:divider="@android:color/transparent"
        android:dividerHeight="0dp"
        android:background="#FFF" />

</android.support.v4.widget.DrawerLayout>

然后我调用以下函数：

private void setupFragments() {
    // Check that the activity is using the correct layout
    if (findViewById(R.id.main_frame) != null) {
        // Initialize the first fragment
        MainFragment firstFrag = new MainFragment();

        // Pass any extras from an intent to the Fragment
        firstFrag.setArguments(getIntent().getExtras());

        // Add the first Fragment to the screen
        getSupportFragmentManager().beginTransaction()
            .add(R.id.main_frame,firstFrag).commit();

        tabsAdapter = firstFrag.getAdapter();
        Log.d("Base.LOG","tabsAdapter = " + tabsAdapter);
        tabsAdapter.addTab(DummyFragment.class,null);
    }
}

尝试将FragmentStatePagerAdapter设置为片段布局(R.layout.main)中视图的适配器：

<android.support.v4.view.ViewPager
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/main_page"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainFragment" >

    <android.support.v4.view.PagerTitleStrip
        android:id="@+id/pager_title_strip"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="top"
        android:background="#33b5e5"
        android:textColor="#fff"
        android:paddingTop="4dp"
        android:paddingBottom="4dp" />
</android.support.v4.view.ViewPager>

我的片段代码看起来像这样：

private View mView;
private TabbedPagerAdapter mTabPageAdapter;
private ViewPager mTabPager;

@Override
public View onCreateView(LayoutInflater inflater,ViewGroup container,Bundle savedInstanceState) {
    Log.d("Main.LOG","onCreate called");
    mView = inflater.inflate(R.layout.main,container,false);
    Log.d("Main.LOG","Layout inflated");
    setupTabs();
    Log.d("Main.LOG","Tabs setup");

    return mView;
}

@Override
public void onResume() {
    super.onResume();
    Log.d("Main.LOG","onResume called");
}

/** Set up the ViewPager and Adapter to handle the primary tabs */
private void setupTabs() {
    // Initialize the adapter
    mTabPageAdapter = new TabbedPagerAdapter(getActivity(),getActivity().getSupportFragmentManager());

    // Initialize the view pager
    mTabPager = (ViewPager) mView.findViewById(R.id.main_page);
    Log.d("Main.LOG","mTabPager = " + mTabPager);
    Log.d("Main.LOG","mTabPageAdapter = " + mTabPageAdapter);
    mTabPager.setAdapter(mTabPageAdapter);
}

/* Accessor for TabbedPagerAdapter */
public TabbedPagerAdapter getAdapter() {
    return mTabPageAdapter;
}

当我尝试添加带有NullPointerException的选项卡时,app force关闭.日志中的调试消息显示：

D/Base.LOG(27173): tabsAdapter = null

在任何片段的调试消息之前显示.在尝试访问任何视图或子类之前,如何确保布局膨胀？

根据我的评论

public class MainFragment extends Fragment
{
    private MainInterface mInterface = null;
    //make sure to set the above somehow

    public interface MainInterface{
        public void onFragmentReady(.....);
    }

    ... //Do regular stuff here

    public void onResume()
    {
        //Do what you need to do in onResume
        if(mInterface != null)
        {
            mInteface.onFragmentReady();
        }
    }
}

这应该可以让你知道片段何时准备就绪,然后你可以进行getTabAdapter调用.