Question

我正在尝试按照Udacity开发Android应用程序课程。我得到了课程3.03。在此，我们被要求在点击列表中的项目时从DetailActivity启动新的活动（ForecastFragment）。

但是，在尝试启动DetailActivity时，我一直收到错误消息。 Binary XML file line #1: Error inflating class fragment，DetailActivity.java方法onCreate()引起的。{/ 1}。

我已经四处搜索了，但是没有一个针对这个问题的修正案对我有帮助。

具体错误是：

Caused by: android.app.Fragment$InstantiationException: Trying to instantiate a class
com.myapp.sunshine.app.DetailActivityFragment that is not a Fragment

DetailActivity.java

public class DetailActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_detail); //failing here
    }
}

DetailActivityFragment.java

public class DetailActivityFragment extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_detail, container, false);
    }
 }

activity_detail.xml

<fragment xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" android:id="@+id/fragment"
    android:name="com.myapp.sunshine.app.DetailActivityFragment"
    tools:layout="@layout/fragment_detail" android:layout_width="match_parent"
    android:layout_height="match_parent" />

我应该提一下，我不使用支持库 - 因为我的目标是SDK 21+，仅限Lollipop。

这不是我们在课程中创建的唯一片段。我们创建的另一个片段看起来与此相同。

activity_main.xml中

<fragment xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" android:id="@+id/fragment"
    android:name="com.myapp.sunshine.app.ForecastFragment"
    tools:layout="@layout/fragment_main" android:layout_width="match_parent"
    android:layout_height="match_parent" />

好的方面，我包括ForecastFragment课程。我省略了不必要的代码部分。

ForecastFragment.java

public class ForecastFragment extends Fragment {

    private ArrayAdapter<String> mForecaseAdapter;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setHasOptionsMenu(true);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {

        String[] forecastArray = {
                "Today - Sunny - 88/63",
                "Tomorrow - Foggy - 74/58",
                "Sunday - Rainy - 65/59",
                "Monday - Cloudy - 72/67"
        };
        final List<String> weekForecast = new ArrayList<>(Arrays.asList(forecastArray));

        mForecaseAdapter = new ArrayAdapter<>(
                getActivity(),
                R.layout.list_item_forecast,
                R.id.list_item_forecast_textview,
                weekForecast);

        View rootView = inflater.inflate(R.layout.fragment_main, container, false);

        final ListView listView = (ListView) rootView.findViewById(R.id.listview_forecast);
        listView.setAdapter(mForecaseAdapter);

        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
             @Override
             public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                String forecast = mForecaseAdapter.getItem(position);
                Intent detailActivityIntent = new Intent(getActivity(), DetailActivity.class)
                        .putExtra(Intent.EXTRA_TEXT, forecast);
                startActivity(detailActivityIntent);
            }
        });

        return rootView;
    }
}

fragment_detail.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".DetailActivityFragment">

<TextView android:text="@string/hello_world" android:layout_width="wrap_content"
    android:layout_height="wrap_content" />

</RelativeLayout>

几乎与

相同

fragment_main.xml

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivityFragment">

<ListView
    android:id="@+id/listview_forecast"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_gravity="center" />

</FrameLayout>

Answer 1

您应该使用FragmentActivity代替Activity

public class DetailActivity extends FragmentActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_detail); //failing here
    }
}

二进制XML文件行＃1：错误膨胀类片段

1 个答案: