Question

我是android新手。我的应用程序在运行时在logCat上显示以下错误。任何帮助表示赞赏。

我已将“Home”类声明为导航抽屉的一部分。当我插入此代码时，似乎存在问题。

提前致谢。

Java代码：

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;
import java.util.ArrayList;
import java.util.HashMap;

public class Home extends Fragment
{
    private GoogleMap mMap;
    private ArrayList<MyMarker> mMyMarkersArray = new ArrayList<MyMarker>();
    private HashMap<Marker, MyMarker> mMarkersHashMap;

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

        // Initialize the HashMap for Markers and MyMarker object
        mMarkersHashMap = new HashMap<Marker, MyMarker>();

        mMyMarkersArray.add(new MyMarker("loc1", "icon1", Double.parseDouble("44.637564"), Double.parseDouble("-63.5753207")));
        mMyMarkersArray.add(new MyMarker("loc2", "icon2", Double.parseDouble("44.6462628"), Double.parseDouble("-63.5721407")));
        mMyMarkersArray.add(new MyMarker("loc3", "icon3", Double.parseDouble("44.6470678"), Double.parseDouble("-63.5747943")));
        mMyMarkersArray.add(new MyMarker("loc4", "icon4", Double.parseDouble("43.5643397"), Double.parseDouble("-65.5643972")));
        mMyMarkersArray.add(new MyMarker("loc5", "icon5", Double.parseDouble("44.6556674"), Double.parseDouble("-63.6056877")));
        mMyMarkersArray.add(new MyMarker("loc6", "icon6", Double.parseDouble("44.6892204"), Double.parseDouble("44.6892204")));
        mMyMarkersArray.add(new MyMarker("loc7", "icon7", Double.parseDouble("44.6367517"), Double.parseDouble("-63.5839683")));
        mMyMarkersArray.add(new MyMarker("loc8", "icondefault", Double.parseDouble("44.6508492"), Double.parseDouble("-63.592472")));

        setUpMap();

        plotMarkers(mMyMarkersArray);
    }

    private void plotMarkers(ArrayList<MyMarker> markers)
    {
        if(markers.size() > 0)
        {
            for (MyMarker myMarker : markers)
            {
                // Create user marker with custom icon and other options
                MarkerOptions markerOption = new MarkerOptions().position(new LatLng(myMarker.getmLatitude(), myMarker.getmLongitude()));
                markerOption.icon(BitmapDescriptorFactory.fromResource(R.drawable.smallicon1));
                Marker currentMarker = mMap.addMarker(markerOption);
                mMarkersHashMap.put(currentMarker, myMarker);
                mMap.setInfoWindowAdapter(new MarkerInfoWindowAdapter());
            }
        }
    }

    private int manageMarkerIcon(String markerIcon)
    {
        if (markerIcon.equals("icon1"))
            return R.drawable.smallicon1;
        else if(markerIcon.equals("icon2"))
            return R.drawable.smallicon1;
        else if(markerIcon.equals("icon3"))
            return R.drawable.smallicon1;
        else if(markerIcon.equals("icon4"))
            return R.drawable.smallicon1;
        else if(markerIcon.equals("icon5"))
            return R.drawable.smallicon1;
        else if(markerIcon.equals("icon6"))
            return R.drawable.smallicon1;
        else if(markerIcon.equals("icon7"))
            return R.drawable.smallicon1;
        else
            return R.drawable.smallicon1;
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_feedback, container, false);
    }

    private void setUpMap()
    {
        // Do a null check to confirm that we have not already instantiated the map.
        if (mMap == null)
        {
            // Try to obtain the map from the SupportMapFragment.
            mMap = ((SupportMapFragment) getFragmentManager().findFragmentById(R.id.map)).getMap();

            // Check if we were successful in obtaining the map.

            if (mMap != null)
            {
                mMap.setOnMarkerClickListener(new GoogleMap.OnMarkerClickListener()
                {
                    @Override
                    public boolean onMarkerClick(com.google.android.gms.maps.model.Marker marker)
                    {
                        marker.showInfoWindow();
                        return true;
                    }
                });
            }
            else
                Toast.makeText(getActivity().getApplicationContext(), "Unable to create Maps", Toast.LENGTH_SHORT).show();
        }
    }

    public class MarkerInfoWindowAdapter implements GoogleMap.InfoWindowAdapter
    {
        public MarkerInfoWindowAdapter()
        {
        }

        @Override
        public View getInfoWindow(Marker marker)
        {
            return null;
        }

        @Override
        public View getInfoContents(Marker marker)
        {
            View v  = getActivity().getLayoutInflater().inflate(R.layout.infowindow_layout, null);

            MyMarker myMarker = mMarkersHashMap.get(marker);

            ImageView markerIcon = (ImageView) v.findViewById(R.id.marker_icon);

            TextView markerLabel = (TextView)v.findViewById(R.id.marker_label);

            TextView anotherLabel = (TextView)v.findViewById(R.id.another_label);

            markerIcon.setImageResource(manageMarkerIcon(myMarker.getmIcon()));

            markerLabel.setText(myMarker.getmLabel());
            anotherLabel.setText("A custom text");

            return v;
        }
    }

    public void onDestroy()
    {
        super.onDestroy();

    }

    @Override
    public void onDetach()
    {
        super.onDetach();
    }
}

Tomcat的：

10-28 17:06:11.301  13300-13300/com.example.chid.parktrial1 W/dalvikvm﹕ 
threadid=1: thread exiting with uncaught exception (group=0x4181cc08)
10-28 17:06:11.306  13300-13300/com.example.chid.parktrial1 E/AndroidRuntime﹕ 
FATAL EXCEPTION: main Process: com.example.chid.parktrial1, PID: 13300 java.lang.RuntimeException: Unable to start activity ComponentInfo
{com.example.chid.parktrial1/com.example.chid.parktrial1.SuperPark}: 
java.lang.NullPointerException
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2447)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2507)
    at android.app.ActivityThread.access$900(ActivityThread.java:172)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1308)
    at android.os.Handler.dispatchMessage(Handler.java:102)
    at android.os.Looper.loop(Looper.java:146)
    at android.app.ActivityThread.main(ActivityThread.java:5692)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:515)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1291)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1107)
    at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
    at com.example.chid.parktrial1.Home.setUpMap(Home.java:149)
    at com.example.chid.parktrial1.Home.onCreate(Home.java:87)
    at android.support.v4.app.Fragment.performCreate(Fragment.java:1942)
    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1040)
    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1259)
    at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:738)
    at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1624)
    at android.support.v4.app.FragmentController.execPendingActions(FragmentController.java:330)
    at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:547)
    at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1177)
    at android.app.Activity.performStart(Activity.java:5551)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2420)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2507)
    at android.app.ActivityThread.access$900(ActivityThread.java:172)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1308)
    at android.os.Handler.dispatchMessage(Handler.java:102)
    at android.os.Looper.loop(Looper.java:146)
    at android.app.ActivityThread.main(ActivityThread.java:5692)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:515)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1291)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1107)
    at dalvik.system.NativeStart.main(Native Method)
10-28 17:06:14.401  13300-13300/com.example.chid.parktrial1 I/Process﹕ Sending signal. PID: 13300 SIG: 9

Answer 1

无法评论，因此很难指出评论中可以实现的小事。

PS：正确格式化您的问题以更好地理解问题

反正，添加LayoutInflater并使用getInfoComponents()方法中的Layoutinflater对视图进行充气。由于您要在片段中定义视图。

public class Home extends Fragment{

    LayoutInflater inflater=null;



    ...

     public class MarkerInfoWindowAdapter implements GoogleMap.InfoWindowAdapter {

        // constuctor
        public MarkerInfoWindowAdapter(LayoutInflater inflater) {
            this.inflater=inflater;
        }

        @Override
        public View getInfoContents(Marker marker) {
            View v = inflater.inflate(R.layout.infowindow_layout, null);

            }
        }

}

使用LayoutInflater对View

中的getInfoComponents()进行充气

Android Studio-E / AndroidRuntime：FATAL EXCEPTION：main -maps V2

1 个答案: