java - Android - map 不会水平滚动

Question

我在我的 Android 项目中使用 Google Maps V2。我已经(使用向导)创建了一个带有可滚动选项卡 + 滑动的 Activity ，在我的一个布局中我使用的是 SupportMapFragment，但是在 map 中我无法水平滚动 map ，当在 map 内滑动时它会显示另一种观点。这是我的代码:

主 Activity

    public class MainActivity extends FragmentActivity {

    private List<Fragment> paginas;

    /**
     * The {@link android.support.v4.view.PagerAdapter} that will provide
     * fragments for each of the sections. We use a
     * {@link android.support.v4.app.FragmentPagerAdapter} derivative, which
     * will keep every loaded fragment in memory. If this becomes too memory
     * intensive, it may be best to switch to a
     * {@link android.support.v4.app.FragmentStatePagerAdapter}.
     */
    SectionsPagerAdapter mSectionsPagerAdapter;

    /**
     * The {@link ViewPager} that will host the section contents.
     */
    ViewPager mViewPager;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        if(paginas==null){
            paginas = new ArrayList<Fragment>();
            paginas.add(new LocalizacaoPesquisadorActivity());
            paginas.add(new VotosPorRegiaoActivity());
        }

        // Create the adapter that will return a fragment for each of the three
        // primary sections of the app.
        mSectionsPagerAdapter = new SectionsPagerAdapter(
                getSupportFragmentManager());

        // Set up the ViewPager with the sections adapter.
        mViewPager = (ViewPager) findViewById(R.id.pager);
        mViewPager.setAdapter(mSectionsPagerAdapter);



    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    /**
     * A {@link FragmentPagerAdapter} that returns a fragment corresponding to
     * one of the sections/tabs/pages.
     */
    public class SectionsPagerAdapter extends FragmentPagerAdapter {

        public SectionsPagerAdapter(FragmentManager fm) {
            super(fm);
        }

        @Override
        public Fragment getItem(int position) {
            // getItem is called to instantiate the fragment for the given page.
            // Return a DummySectionFragment (defined as a static inner class
            // below) with the page number as its lone argument.
            switch (position) {
            case 0:
                return paginas.get(0);
            case 1:
                return paginas.get(1);
            default: return null;

            }           
        }

        @Override
        public int getCount() {
            // Show 3 total pages.
            return paginas.size();
        }

        @Override
        public CharSequence getPageTitle(int position) {
            Locale l = Locale.getDefault();
            switch (position) {
            case 0:
                return getString(R.string.title_activity_localizacao_pesquisador).toUpperCase(l);
            case 1:
                return getString(R.string.title_activity_votos_por_regiao).toUpperCase(l);          
            }
            return null;
        }
    }



}

LocalizacaoPesquisadorActivity

public class LocalizacaoPesquisadorActivity extends Fragment {

public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.activity_localizacao_pesquisador,
            container, false);
    System.out.println();
    return rootView;
}


}

activity_main.xml

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

    <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:paddingBottom="4dp"
        android:paddingTop="4dp"
        android:textColor="#fff" />

</android.support.v4.view.ViewPager>

activity_localizacao_pesquisador.xml

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

    <EditText
        android:id="@+id/editTextDataLocalizacaoPesquisador"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentRight="true"
        android:inputType="none"
        android:hint="Data" 
        android:layout_marginLeft="8dp"
        android:layout_marginRight="8dp"
        android:layout_marginTop="4dp"
        android:layout_marginBottom="4dp"/>

    <Spinner
        android:id="@+id/spinnerHorarioLocalizacaoPesquisador"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/editTextDataLocalizacaoPesquisador"
        android:layout_alignRight="@+id/editTextDataLocalizacaoPesquisador"
        android:layout_below="@+id/editTextDataLocalizacaoPesquisador"
        android:layout_marginTop="4dp"
        android:layout_marginBottom="4dp" />

    <Button
        android:id="@+id/buttonAtualizarLocalizacaoPesquisador"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/editTextDataLocalizacaoPesquisador"
        android:layout_alignRight="@+id/editTextDataLocalizacaoPesquisador"
        android:layout_below="@+id/spinnerHorarioLocalizacaoPesquisador"
        android:text="Atualizar"
        android:layout_marginTop="4dp"
        android:layout_marginBottom="4dp"
        android:onClick="atuarlizarMapaLocalizacaoPesquisador" />

    <fragment android:id="@+id/mapaLocalizacaoPesquisador"
        android:name="com.google.android.gms.maps.SupportMapFragment"
        android:layout_below="@+id/buttonAtualizarLocalizacaoPesquisador"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/buttonAtualizarLocalizacaoPesquisador"
        android:layout_alignRight="@+id/buttonAtualizarLocalizacaoPesquisador"
        android:layout_alignParentBottom="true"
        android:layout_marginBottom="4dp"
        android:layout_marginTop="4dp"        
        map:cameraTargetLat="-23.531152"
        map:cameraTargetLng="-46.789876"
        map:cameraZoom="1"
        />

</RelativeLayout>

我想拦截在 map 上的滑动 Action ，你怎么看？

Answer 1

首先，更新您的 Android SDK 并通过从 <android-sdk>\extras\android\support\v4\android-support-v4.jar 复制来确保您使用的是最新版本的 Android 支持库。 .旧版本的支持库无法正确处理此问题。

然后扩展 ViewPager 对象:

/**
 * Extension of ViewPager that allows the user to move the map
 * inside the fragment, but still supports swiping to the
 * next fragment via "bezel swipe" (i.e., swiping from the edge)
 */
public class ViewPagerMapBevelScroll extends android.support.v4.view.ViewPager {

    private static final int DEFAULT_SWIPE_MARGIN_WIDTH_DIP = 20;
    private int swipeMarginWidth;

    public ViewPagerMapBevelScroll(Context context) {
        super(context);
        setDefaultSwipeMargin(context);
    }

    public ViewPagerMapBevelScroll(Context context, AttributeSet attrs) {
        super(context, attrs);
        setDefaultSwipeMargin(context);
    }

    private void setDefaultSwipeMargin(final Context context) {
        swipeMarginWidth = (int) (DEFAULT_SWIPE_MARGIN_WIDTH_DIP * context
                .getResources().getDisplayMetrics().density);
    }

    @Override
    protected boolean canScroll(View v, boolean checkV, int dx, int x, int y) {
            if (v instanceof ViewPagerMapBevelScroll) {
                if (getCurrentItem() == SectionsPagerAdapter.MAP_TAB) {
                    return !isAllowedMapSwipe(x, dx);
                }
            }
            return super.canScroll(v, checkV, dx, x, y);
        }

    /**
     * Determines if the pointer movement event at x and moved pixels is
     * considered an allowed swipe movement overriding the inner horizontal
     * scroll content protection.
     * 
     * @param x X coordinate of the active touch point
     * @param dx Delta scrolled in pixels
     * @return true if the movement should start a page swipe
     */
    protected boolean isAllowedMapSwipe(final float x, final float dx) {        
        return ((x < swipeMarginWidth) && (dx > 0))
            || ((x > (getWidth() - swipeMarginWidth)) && (dx < 0));
    }
}

然后，更改您的布局以使用 ViewPagerMapBevelScroll (确保更改包名称以匹配 ViewPagerMapBevelScroll 对象的位置):

<com.your.package.ViewPagerMapBevelScroll 
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/pager"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >

然后，更改您的 SectionsPagerAdapter添加 MAP_TAB我们在 ViewPagerMapBevelScroll 中引用的值，并将其设置为等于包含 map 的选项卡的索引:

public class SectionsPagerAdapter extends FragmentStatePagerAdapter {

    public static final int MAP_TAB = 0; // Set this equal to 
                                         // the index of your map tab

    public SectionsPagerAdapter(FragmentManager fm) {
        super(fm);
    }
...
}

如果您想查看完整的工作版本，请查看开源 GPSTest app .

isAllowedMapSwipe 的功劳方法转到 Martin Hochstrasser(参见 http://goo.gl/Hyl2E)

[2013 年 11 月 8 日更新] - 请注意，根据 BornToCode 对此答案的评论，最新的支持库为 ViewPager和 Google Play 服务库，Android 3.0 (Honeycomb) 及更高版本不再需要此解决方法，但仍需要在 Android 2.3 (Gingerbread) 和 Android 2.2 (Froyo) 上获得正确的行为。