Question

我有以下自定义寻呼机适配器，我从我的活动中调用并传递一些参数。一切都很好。我得到了纬度和经度的字符串。

class CustomPagerAdapter extends PagerAdapter {

    Context context;

    private final ArrayList<String> latitude;
    private final ArrayList<String> longitude;


    public CustomPagerAdapter(Activity context,ArrayList<String> latitude,ArrayList<String> longitude) {
        this.context = context;
        this.latitude= latitude;
        this.longitude = longitude;
    }

    @Override
    public int getCount() {
        return latitude.size();
    }

    @Override
    public boolean isViewFromObject(View view, Object object) {
        return view == (object);
    }

    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        LayoutInflater layoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View itemView = layoutInflater.inflate(R.layout.pager_item, container, false);

        ImageView imageView = (ImageView) itemView.findViewById(R.id.listpager_imageView);
        TextView latitude = (TextView) itemView.findViewById(R.id.listpager_text);
        TextView longitude = (TextView) itemView.findViewById(R.id.listpager_title);
        latitude.setText(this.latitude.get(position));
        longitude.setText(this.longitude.get(position));


        container.addView(itemView);

        return itemView;
    }

    @Override
    public void destroyItem(ViewGroup container, int position, Object object) {
        container.removeView((RelativeLayout) object);
    }
}

我也有这个地图片段，如果我从这样的活动中调用它，它工作正常：

 FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
// Replace the contents of the container with the new fragment
    ft.replace(R.id.your_placeholder, New MapFragment());
// Complete the changes added above
    ft.commit();

这是片段：

public class MapFragment extends Fragment {

    MapView mapView;
    GoogleMap map;
    private double latitude,longitude;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.listviewtopager, container, false);


        // Gets the MapView from the XML layout and creates it
        mapView = (MapView) v.findViewById(R.id.mapview);
        mapView.onCreate(savedInstanceState);

        // Gets to GoogleMap from the MapView and does initialization stuff
        map = mapView.getMap();
        map.getUiSettings().setMyLocationButtonEnabled(false);
        map.setMyLocationEnabled(true);

        // Needs to call MapsInitializer before doing any CameraUpdateFactory calls
        MapsInitializer.initialize(this.getActivity());

        // Updates the location and zoom of the MapView
        CameraUpdate cameraUpdate = CameraUpdateFactory.newLatLngZoom(new LatLng(1.56, 43.433), 10);
        map.animateCamera(cameraUpdate);

        return v;
    }

    @Override
    public void onResume() {
        mapView.onResume();
        super.onResume();
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        mapView.onDestroy();
    }

    @Override
    public void onLowMemory() {
        super.onLowMemory();
        mapView.onLowMemory();
    }

}

我想要做的是在CustomPagerAdapter中引入片段，所以当我每次刷卡时从活动中调用CustomPagerAdapter时，将加载一个新片段。 your_placeholder id就是这个

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

有可能这样做吗？如果我没有正确解释问题，我很抱歉。如果您有任何疑问，我会尝试编辑它。谢谢。

编辑：我有的另一个问题 - ＆gt;当我按下后退按钮时，pagerActivity再次启动，它不会关闭它。我必须按两次才能关闭它。

Answer 1

确定可以用PagerAdapter替换片段;我用它。由于有人提出它，FragmentPagerAdapter类可以使处理片段更容易，因此同名。我没有用它。无论哪种方式，代码都应该类似。

关于按后退按钮。如果你想有这种效果。以下是您的示例代码：

FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
// Replace the contents of the container with the new fragment
ft.replace(R.id.your_placeholder, New MapFragment());

ft.addToBackStack(null);       // support the Back key

// Complete the changes added above
ft.commit();

注意：添加方法 addToBackStack

如何在PagerAdapter中实例化片段？

1 个答案: