使用MapView在片段之间切换

Question

我有一个带有底栏的main_activity。我正在使用这个底栏在片段之间导航。然而，有一个片段不能通过底部栏直接导航。它必须通过MapView和onInfowindowClick从片段中访问。然而，每当我使用InfoWindow时，该应用程序就会崩溃。这是我的代码

public void onMapReady(GoogleMap googleMap) {
        BitmapDescriptor icon = BitmapDescriptorFactory.fromResource(R.drawable.tesla);
        mMap=googleMap;
        for (Location item : array_list) {
            String _title = item.getLocation_name();
            String _snippet = item.getLocation_address();
            LatLng _latLng = new LatLng(item.getLatitude(), item.getLongitude());
            final MarkerOptions mMarkerOptions = new MarkerOptions().icon(icon);
            mMarkerOptions.position(_latLng).title(_title).snippet(_snippet).flat(true);
            Marker marker = mMap.addMarker(mMarkerOptions);
            mMarkerHashMap.put(marker, item);

            CameraPosition cameraPosition = new CameraPosition.Builder()
                    .target(marker.getPosition())
                    .zoom(12.0f)
                    .build();
            mMap.animateCamera(CameraUpdateFactory
                    .newCameraPosition(cameraPosition));

            mMap.setOnInfoWindowClickListener(new GoogleMap.OnInfoWindowClickListener() {
                @Override
                public void onInfoWindowClick(Marker marker) {
                    LocationDetailFragment detailedlocation = new LocationDetailFragment();

                    detailedlocation.LOCATION = mMarkerHashMap.get(marker);
                    FragmentTransaction ft = getFragmentManager().beginTransaction();
                    ft.replace(R.id.content, detailedlocation);
                    ft.addToBackStack(null);
                    ft.commit();
                }
            });
        }

                                                                             --------- beginning of crash 04-23 19:41:11.380 2573-2573/com.teslaqubitsins.fasih.teslahcm E/AndroidRuntime: FATAL

异常：main process：com.teslaqubitsins.fasih.teslahcm,pid：2573 java.lang.nullpointerexception：试图在com.teslaqubitsins.fasih.teslahcm.locationDetailfragment.oncreateView（locationDetailfragment.java:35)和Android.support.v4.app.fragment.performCreateView（fragment.java:2192)和Android.support.v4.app.fragment.moveToState（在Android.support.v4.app.fragmentManagerimpl.moveFragmentToExpectedState（FragmentManager.java:1528)在Android.support.v4.app.fragmentManagerimpl.moveToState（FragmentManager.java:1595)在Android.support.v4.app.backstackRecord.executeOps（BackstackRecord.java:758)在Android.support.v4.app.fragmentManagerimpl.executeOps（FragmentManager.java:2363)在执行（碎片）nager.java:2103)在Android.support.v4.app.fragmentManagerImpl.execPendingActions(FragentManager.java:2013)，android.support.v4.app.fragmentManagerImpl$1.run(FragmentManager.java:710)，android.support.v4.app.fragmentManagerImpl.run（fragmentManager.java:71)，android.os.handler.handleCallback（handler.java:751)在Android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:886)at com.android.internal.os.zygoteinit.main(zygoteinit.java:776)04-23 19:41:11.383 156 4-1957/system_process W/activitymanager：强制完成活动com.teslaqubitsins.fasih.teslahcm/.mainactivity 04-23 19:41:11.414 129 6-1653/？E/surfaceflinger:ro.sf.lcd_density必须定义

                                             [ 04-23 19:41:11.456  1564: 3367 D/         ]
                                             HostConnection::get() New Host Connection established 0x87cb5680, tid 3367 04-23

19:41:11.457 129 6-1653/？d/gralloc_ranchu:gralloc_alloc:格式1和用法0x900意味着创建主机颜色缓冲区04-23 19:41:11.457 156 4-3367/system_process I/openglenderer:初始化EGL，版本1.4 04-23 19:41:11.458 156 4-3367/system_process D/openglenderer:交换行为1 04-23 19:41:11.458 156 4-3367/system_process W/openglenderer:选择带有EGL_SWAP_Behavior_President的配置失败，正在重试，没有...04-23 19:41:11.458 156 4-3367/System_Process D/OpenGlenderer：交换行为0.04-23 19:41:11.462 129 6-1653/？d/gralloc_ranchu:gralloc_alloc:格式1和用法0x900意味着创建主机颜色缓冲区04-23 19:41:11.476 129 6-1653/？d/gralloc_ranchu:gralloc_alloc:格式1和用法0x900意味着创建主机颜色缓冲区04-23 19:41:11.892 156 4-1591/system_process W/activitymanager:Activity pause timeout for ActivityRecord{34a233 u0 com.teslaqubitsins.fasih.teslahcm/.mainactivity t141 f}04-23 19:41:11.921 129 6-1962/？d/gralloc_ranchu:gralloc_alloc:格式1和用法0x900意味着创建主机颜色缓冲区04-23 19:41:11.940 129 6-1962/？d/gralloc_ranchu:gralloc_alloc:格式1和用法0x900意味着创建主机颜色缓冲区04-23 19:41:11.951 129 6-1962/？d/gralloc_ranchu:gralloc_alloc:格式1和用法0x900意味着创建主机颜色缓冲区04-23 19:41:11.968 129 6-1426/？d/permissioncache：检查Android.permission.read_frame_buffer for UID=1000=>grated（252 us)04-23 19:41:12.025 129 6-1426/？d/gralloc_ranchu:gralloc_alloc:格式1和用法0x333意味着创建主机颜色缓冲区块引号

package com.teslaqubitsins.fasih.teslahcm;


import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.v4.app.DialogFragment;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;



public class LocationDetailFragment extends Fragment {
    public static Location LOCATION;
    TextView _campusName;
    TextView _campusAddress;


    public LocationDetailFragment() {
    }


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

        View view=inflater.inflate(R.layout.fragment_location_detail, container, false);

        _campusName = (TextView) getView().findViewById(R.id.campus_name);
        _campusAddress = (TextView) getView().findViewById(R.id.campus_address);

        _campusName.setText(LOCATION.getLocation_name());
        _campusAddress.setText(LOCATION.getLocation_address());
        return view;

    }
    public void onClick_call(View view) {
        dialPhoneNumber(LOCATION.getLocation_phone());
    }
    public void dialPhoneNumber(String phoneNumber) {
        Intent intent = new Intent(Intent.ACTION_DIAL);
        intent.setData(Uri.parse("tel:" + phoneNumber));
        if (intent.resolveActivity(getActivity().getPackageManager()) != null) {
            startActivity(intent);
        }
    }
}

04-23 19:58:11.735 685 6-6856/com.teslaqubitsins.fasih.teslahcm e/androidruntime：致命异常：main process：com.teslaqubitsins.fasih.teslahcm,pid:6856 java.lang.nullpointerexception：试图在com.teslaqitsins.fasih.teslahcm.locationdetailfragment.oncreateview（locationdetailfragment.java.app.fragment.performcreateview（2192）在Android.support.v4.app.fragmentManagerImpl.moveToState（fragmentManager.java:1299)在Android.support.v4.app.fragmentManagerImpl.moveFragmentToExpectedState（fragmentManager.java:1528)在Android.support.v4.app.fragmentManagerImpl.moveState（fragmentManager.java:1595)在Android.support.v4.app.fragmentManagerImpl.moveToState（ExecuteOpstoGether（FragmentManager.java:2149)在Android.support.v4.app.fragmentManagerImpl.OptimizeandExecuteOps(FragentManager.java:2103)，在Android.support.v4.app.fragmentManagerImpl.execPendingActions(FragentManager.java:2013)，在Android.support.v4.app.fragmentManagerImpl$1.run(FragmentManager.java:710)，在.main（activitythread.java:6119)在java.lang.reflect.Method.invoke（本机方法）在com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:886)在com.android.internal.os.zygoteinit.main(zygoteinit.java:776)04-23 19:58:12.507 2006-2282/com.google.android.googleQuicksearchbox：search W/GMSLocationProvider：删除位置更新时出错：16

Answer 1

而不是：

 _campusName = (TextView) getView().findViewById(R.id.campus_name);
 _campusAddress = (TextView) getView().findViewById(R.id.campus_address);

使用片段的膨胀视图获取ID：

 _campusName = (TextView) view.findViewById(R.id.campus_name);
 _campusAddress = (TextView) view.findViewById(R.id.campus_address);

当您的getview()返回null时会发生异常，它与片段的视图没有关联。在片段中，必须始终使用膨胀视图的引用。