1

我的应用程序具有以下特点。

  • 在横向模式下，将屏幕分成两半并显示几个片段（“LocFragment”和“MapFragment”）。
  • 在纵向模式下，在 ActionBar 中显示 2 个选项卡。一个 Fragment 覆盖整个屏幕，并在 Fragments 之间切换，带有 Tab 选择。
  • 针对 4.x+，所以我不关心支持库或 ActionBarSherlock。

如果应用程序启动时手机处于横向模式，则一切正常。但是当 1) 手机处于纵向模式，2) 应用程序启动，以及 3) 手机转为横向模式时，应用程序会崩溃。

layour/activity_main.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">

    <FrameLayout
        android:id="@+id/FragmentContainer"
        android:layout_width="match_parent" 
        android:layout_height="match_parent">
    </FrameLayout>


 layout-land/activity_main.xml

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

    <fragment
        android:name="org.solamour.eq.LocFragment"
        android:id="@+id/EarthquakeListFragment"
        android:layout_weight="1"
        android:layout_width="0dp"
        android:layout_height="match_parent" />
    <fragment
        android:name="org.solamour.eq.MapFragment"
        android:id="@+id/EarthquakeMapFragment"
        android:layout_weight="1"
        android:layout_width="0dp"
        android:layout_height="match_parent" />


public class MainActivity extends Activity {
    TabListener<LocFragment> locTabListener;
    TabListener<MapFragment> mapTabListener;

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

        ActionBar actionBar = getActionBar();
        View fragmentContainer = findViewById(R.id.FragmentContainer);
        boolean bLandscape = fragmentContainer == null;

        if (!bLandscape) {
            actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
            actionBar.setDisplayShowTitleEnabled(false);

            Tab listTab = actionBar.newTab();
            locTabListener = new TabListener<LocFragment>
                (this, R.id.FragmentContainer,
                        LocFragment.class);
            listTab.setText("List")
                .setContentDescription("List of locations")
                .setTabListener(locTabListener);
            actionBar.addTab(listTab);

            Tab mapTab = actionBar.newTab();
            mapTabListener = new TabListener<MapFragment>
                (this, R.id.FragmentContainer,
                        MapFragment.class);
            mapTab.setText("Map")
                .setContentDescription("Map of interests")
                .setTabListener(mapTabListener);
            actionBar.addTab(mapTab);
        }
    }

    @Override
    public void onSaveInstanceState(Bundle outState) {
        View fragmentContainer = findViewById(R.id.FragmentContainer);
        boolean bLandscape = fragmentContainer == null;

        if (!bLandscape) {
            FragmentTransaction ft =
                    getFragmentManager().beginTransaction();
            if (mapTabListener.fragment != null) {
                ft.detach(mapTabListener.fragment);
            }
            if (locTabListener.fragment != null) {
                ft.detach(locTabListener.fragment);
            }
            ft.commit();
        }

        super.onSaveInstanceState(outState);
    }

    @Override
    public void onRestoreInstanceState(Bundle savedInstanceState) {
        super.onRestoreInstanceState(savedInstanceState);

        View fragmentContainer = findViewById(R.id.FragmentContainer);
        boolean bLandscape = fragmentContainer == null;

        if (!bLandscape) {
            locTabListener.fragment =getFragmentManager().
                    findFragmentByTag(LocFragment.class.getName());
            mapTabListener.fragment = getFragmentManager().
                    findFragmentByTag(MapFragment.class.getName());
        }
    }

    public static class TabListener<T extends Fragment>
            implements ActionBar.TabListener {
        private Fragment fragment;
        private Activity activity;
        private Class<T> fragmentClass;
        private int fragmentContainer;

        public TabListener(Activity activity,
                int fragmentContainer, Class<T> fragmentClass) {
            this.activity = activity;
            this.fragmentContainer = fragmentContainer;
            this.fragmentClass = fragmentClass;
        }

        public void onTabSelected(Tab tab, FragmentTransaction ft) {
            if (fragment == null) {
                String fragmentName = fragmentClass.getName();
                fragment = Fragment.instantiate(activity, fragmentName);
                ft.add(fragmentContainer, fragment, fragmentName);
            } else {
                ft.attach(fragment);
            }
        }

        public void onTabUnselected(Tab tab, FragmentTransaction ft) {
            if (fragment != null) {
                ft.detach(fragment);
            }
        }

        public void onTabReselected(Tab tab, FragmentTransaction ft) {
            if (fragment != null)
                ft.attach(fragment);
        }
    }
}

说到崩溃，Eclipse 只是说“无法启动活动 ComponentInfo{...}: android.view.InflateException: Binary XML file line #7: Error inflating class fragment”。它必须在“setContentView(R.layout.activity_main)”中的某个地方，但我不确定如何设置源代码以在代码中遵循。我会很感激任何建议。谢谢你。

__

溶胶

4

1 回答 1

0

错误在横向布局的第 7 行：

fragment android:name="org.solamour.eq.LocFragment"

也许类的路径是错误的，或者也许 LocFragment 有一个错误，当你显示它时你会崩溃。

于 2012-08-27T13:33:02.607 回答