片段中的錯誤誇大活動：InflateException

Question

我有一個片段，我想單擊片段中的按鈕以打開一個相應的活動，該活動也包含一個片段。

我正在嘗試測試“活動”的顯示方式（單擊按鈕后），並且正在接收似乎是通貨膨脹錯誤的內容。 這是包含查看下一個片段的按鈕的第一個片段：

HomePollsFragment.Java

 mLatestTestButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent latestActivity = new Intent(getActivity().getApplicationContext(), LatestActivity.class);
            startActivity(latestActivity);
        }
    });

然后是在單擊按鈕時打開的活動的代碼：

public class LatestActivity extends AppCompatActivity implements LatestFragment.OnFragmentInteractionListener {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_latest);

    // Check that the activity is using the layout version with
    // the fragment_container FrameLayout
    if (findViewById(R.id.latest_fragment_container) != null) {

        // However, if we're being restored from a previous state,
        // then we don't need to do anything and should return or else
        // we could end up with overlapping fragments.
        if (savedInstanceState != null) {
            return;
        }

        // Create a new Fragment to be placed in the activity layout
        LatestFragment latestFragment = new LatestFragment();

        // In case this activity was started with special instructions from an
        // Intent, pass the Intent's extras to the fragment as arguments
        latestFragment.setArguments(getIntent().getExtras());

        // Add the fragment to the 'fragment_container' FrameLayout
        getSupportFragmentManager().beginTransaction()
                .add(R.id.latest_fragment_container, latestFragment).commit();
    }



}

@Override
public void onFragmentInteraction(Uri uri) {

 }
}

我收到的錯誤在下面，並且似乎與以下行有關：

setContentView(R.layout.activity_latest);

錯誤：

06-27 22:35:47.787 4252-4252/com.sourcey.materialloginexample E/AndroidRuntime: FATAL EXCEPTION: main
                                                                            java.lang.RuntimeException: Unable to start activity ComponentInfo{com.sourcey.materialloginexample/com.troychuinard.fanpolls.LatestActivity}: android.view.InflateException: Binary XML file line #6: Error inflating class fragment
                                                                                at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2211)
                                                                                at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)
                                                                                at android.app.ActivityThread.access$600(ActivityThread.java:141)
                                                                                at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256)
                                                                                at android.os.Handler.dispatchMessage(Handler.java:99)
                                                                                at android.os.Looper.loop(Looper.java:137)
                                                                                at android.app.ActivityThread.main(ActivityThread.java:5103)
                                                                                at java.lang.reflect.Method.invokeNative(Native Method)
                                                                                at java.lang.reflect.Method.invoke(Method.java:525)
                                                                                at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
                                                                                at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
                                                                                at dalvik.system.NativeStart.main(Native Method)
                                                                             Caused by: android.view.InflateException: Binary XML file line #6: Error inflating class fragment
                                                                                at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:713)
                                                                                at android.view.LayoutInflater.rInflate(LayoutInflater.java:755)
                                                                                at android.view.LayoutInflater.inflate(LayoutInflater.java:492)
                                                                                at android.view.LayoutInflater.inflate(LayoutInflater.java:397)
                                                                                at android.view.LayoutInflater.inflate(LayoutInflater.java:353)
                                                                                at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:280)
                                                                                at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:140)
                                                                                at com.troychuinard.fanpolls.LatestActivity.onCreate(LatestActivity.java:14)
                                                                                at android.app.Activity.performCreate(Activity.java:5133)
                                                                                at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
                                                                                at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2175)
                                                                                at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261) 
                                                                                at android.app.ActivityThread.access$600(ActivityThread.java:141) 
                                                                                at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256) 
                                                                                at android.os.Handler.dispatchMessage(Handler.java:99) 
                                                                                at android.os.Looper.loop(Looper.java:137) 
                                                                                at android.app.ActivityThread.main(ActivityThread.java:5103) 
                                                                                at java.lang.reflect.Method.invokeNative(Native Method) 
                                                                                at java.lang.reflect.Method.invoke(Method.java:525) 
                                                                                at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737) 
                                                                                at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 
                                                                                at dalvik.system.NativeStart.main(Native Method) 
                                                                             Caused by: java.lang.NullPointerException: name == null
                                                                                at java.lang.VMClassLoader.findLoadedClass(Native Method)
                                                                                at java.lang.ClassLoader.findLoadedClass(ClassLoader.java:354)
                                                                                at java.lang.ClassLoader.loadClass(ClassLoader.java:491)
                                                                                at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
                                                                                at android.support.v4.app.Fragment.isSupportFragmentClass(Fragment.java:454)
                                                                                at android.support.v4.app.FragmentManagerImpl.onCreateView(FragmentManager.java:2252)
                                                                                at android.support.v4.app.FragmentController.onCreateView(FragmentController.java:120)
                                                                                at android.support.v4.app.FragmentActivity.dispatchFragmentsOnCreateView(FragmentActivity.java:356)
                                                                                at android.support.v4.app.BaseFragmentActivityHoneycomb.onCreateView(BaseFragmentActivityHoneycomb.java:31)
                                                                                at android.support.v4.app.FragmentActivity.onCreateView(FragmentActivity.java:79)
                                                                                at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:689)
                                                                                at android.view.LayoutInflater.rInflate(LayoutInflater.java:755) 
                                                                                at android.view.LayoutInflater.inflate(LayoutInflater.java:492) 
                                                                                at android.view.LayoutInflater.inflate(LayoutInflater.java:397) 
                                                                                at android.view.LayoutInflater.inflate(LayoutInflater.java:353) 
                                                                                at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:280) 
                                                                                at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:140) 
                                                                                at com.troychuinard.fanpolls.LatestActivity.onCreate(LatestActivity.java:14) 
                                                                                at android.app.Activity.performCreate(Activity.java:5133) 
                                                                                at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) 
                                                                                at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2175) 
                                                                                at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261) 
                                                                                at android.app.ActivityThread.access$600(ActivityThread.java:141) 
                                                                                at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256) 
                                                                                at android.os.Handler.dispatchMessage(Handler.java:99) 
                                                                                at android.os.Looper.loop(Looper.java:137) 
                                                                                at android.app.ActivityThread.main(ActivityThread.java:5103) 
                                                                                at java.lang.reflect.Method.invokeNative(Native Method) 
                                                                                at java.lang.reflect.Method.invoke(Method.java:525) 
                                                                                at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737) 
                                                                                at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 
                                                                                at dalvik.system.NativeStart.main(Native Method) 

activity_latest.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">

    <fragment
        android:id="@+id/latest_fragment_container"
        android:layout_weight="1"
        android:layout_width="match_parent"
        android:layout_height="0dp" />

Answer 1

錯誤告訴您<fragment>元素上沒有指定其類的name屬性。

NullPointerException: name == null

但是，您似乎要自己加載Fragment ，所以您不需要<fragment>元素。 相反，你想有一個ViewGroup ，將持有的Fragment動態后FragmentTransaction 。 將您的<fragment>更改為<FrameLayout> 。

Answer 2

那是因為您的activity_latest.xml錯誤。 您試圖將您的LatestFragment添加到Fragment。 您可以像FrameLayout一樣將片段添加到ViewGroup中。 像這里一樣更改代碼。

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">

    <FrameLayout
        android:id="@+id/latest_fragment_container"
        android:layout_weight="1"
        android:layout_width="match_parent"
        android:layout_height="0dp" />