使用Google Maps API v2的ViewPager:神秘的黑色视图

Question

我在视图寻呼机中集成了新的谷歌地图api v2片段.从地图片段滚动时,黑色视图与相邻片段重叠.有人解决了吗？

编辑:截图

public static class PagerAdapter extends FragmentPagerAdapter{

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

    @Override
    public int getCount() {
        return NUM_ITEMS;
    }

    @Override
    public Fragment getItem(int position) {

        Fragment pageFragment;

        switch (position) {
        case 0:
            pageFragment = new TabAFragment();
            break;

        case 1:
            pageFragment = new TabBFragment();
            break;

        case 2:
            pageFragment = SupportMapFragment.newInstance();
            break;

        default:
            pageFragment = null;
            break;
        }

        return pageFragment;
    }
}

Answer 1

通过在ViewPager内部顶部放置一个透明背景的另一个视图,我能够在转换后阻止黑色表面留下FrameLayout:

<FrameLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <android.support.v4.view.ViewPager
        android:id="@+id/fragment_container"
        android:layout_width="match_parent"
        android:layout_height="match_parent" >
    </android.support.v4.view.ViewPager>

    <!-- hack to fix ugly black artefact with maps v2 -->
    <FrameLayout 
        android:layout_width="match_parent"
        android:layout_height="match_parent" 
        android:background="@android:color/transparent" />

</FrameLayout>

Answer 2

与SlidingMenu和ViewPager有同样的问题.我注意到地图片段中的控制按钮在左后方的工件中不是黑色的.我通过重写onCreateView()方法解决了这个问题MapFragment (SupportMapFragment)

@Override
public View onCreateView(LayoutInflater inflater, 
                         ViewGroup view, 
                         Bundle savedInstance) {

    View layout = super.onCreateView(inflater, view, savedInstance);
    FrameLayout frameLayout = new FrameLayout(getActivity());
    frameLayout.setBackgroundColor(
        getResources().getColor(android.R.color.transparent));
    ((ViewGroup) layout).addView(frameLayout,
        new ViewGroup.LayoutParams(
            LayoutParams.FILL_PARENT, 
            LayoutParams.FILL_PARENT
        )
    );
    return layout;
}

Answer 3

Google发布了一个针对此问题的修复程序,但仅适用于4.1+(您不需要下载新版本的PlayServices,他们使用服务器端标志)

这就是我用来绕过这个问题的方法 - 确保你不会在设备上浪费任何CPU周期> = 4.1

public class FixMapFragment extends SupportMapFragment {

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

        View view = super.onCreateView(inflater, container, savedInstanceState);

        // Fix for black background on devices < 4.1
        if (android.os.Build.VERSION.SDK_INT < 
            android.os.Build.VERSION_CODES.JELLY_BEAN) {
            setMapTransparent((ViewGroup) view);
        }
        return view;
    }

    private void setMapTransparent(ViewGroup group) {
        int childCount = group.getChildCount();
        for (int i = 0; i < childCount; i++) {
            View child = group.getChildAt(i);
            if (child instanceof ViewGroup) {
                setMapTransparent((ViewGroup) child);
            } else if (child instanceof SurfaceView) {
                child.setBackgroundColor(0x00000000);
            }
        }
    }
}

Answer 4

我的解决方法:使用GoogleMap的新快照界面,并在滚动页面时显示地图的快照.

这是我设置快照的代码(它与map相同,称为FragmentMap.java):

public void setSnapshot(int visibility) {
    switch(visibility) {
    case View.GONE:
        if(mapFragment.getView().getVisibility() == View.VISIBLE) {
            getMap().snapshot(new SnapshotReadyCallback() {
                @Override
                public void onSnapshotReady(Bitmap arg0) {
                    iv.setImageBitmap(arg0);
                }
            });
            iv.setVisibility(View.VISIBLE);
            mapFragment.getView().setVisibility(View.GONE);
        }
        break;
    case View.VISIBLE:
        if(mapFragment.getView().getVisibility() == View.GONE) {
            mapFragment.getView().setVisibility(View.VISIBLE);
            iv.setVisibility(View.GONE);
        }
        break;
    }
}

"mapFragment"是我的SupportedMapFragment,"iv"是ImageView(make it match_parent).

在这里我控制卷轴:

pager.setOnPageChangeListener(new OnPageChangeListener() {
        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
            if(position == 0 && positionOffsetPixels > 0 || position == 1 && positionOffsetPixels > 0) {
                ((FragmentMap)adapter.getRegisteredFragment(1)).setSnapshot(View.GONE);
            } else if(position == 1 && positionOffsetPixels == 0) {
                ((FragmentMap)adapter.getRegisteredFragment(1)).setSnapshot(View.VISIBLE);
            }
        }
        @Override
        public void onPageScrollStateChanged(int arg0) {}
        @Override
        public void onPageSelected(int arg0) {}
    });

我的带有map(FragmentMap)的片段位于位置1,所以我需要控制从位置0到1以及从位置1到2(第一个if子句)的滚动."getRegisteredFragment()"是我的自定义FragmentPagerAdapter中的一个函数,其中我有一个名为"registeredFragments"的SparseArray(Fragment).

因此,无论何时滚动到地图或从地图滚动,您总能看到它的快照.这对我很有用.