Google上的Java空指针异常放置片段 [英] Java null pointer exception on google places fragment
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问题描述
当我尝试使用自动完成位置功能时，出现了空指针异常.我在文档中添加了该片段，并需要帮助来解决这一问题.谢谢.
I'm getting a null pointer exception when I tried to experiment with the autocomplete places feature. I added the fragment like in the docs and require help in resolving this one. Thank you.
MainActivity
package com.example.srinivas.mapautocompletetest1;
import android.support.v4.app.FragmentActivity;
import android.os.Bundle;
import android.util.Log;
import android.widget.TextView;
import com.google.android.gms.common.api.Status;
import com.google.android.gms.location.places.Place;
import com.google.android.gms.location.places.ui.PlaceAutocompleteFragment;
import com.google.android.gms.location.places.ui.PlaceSelectionListener;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;
public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {
private GoogleMap mMap;
private TextView autocom;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps);
// Obtain the SupportMapFragment and get notified when the map is ready to be used.
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
autocom = (TextView)findViewById(R.id.autotv);
PlaceAutocompleteFragment autocompleteFragment = (PlaceAutocompleteFragment)
getFragmentManager().findFragmentById(R.id.place_autocomplete_fragment);
autocompleteFragment.setOnPlaceSelectedListener(new PlaceSelectionListener() {
@Override
public void onPlaceSelected(Place place) {
// TODO: Get info about the selected place.
// Log.i(TAG, "Place: " + place.getName());
autocom.setText(""+place.getName()+"");
}
@Override
public void onError(Status status) {
// // TODO: Handle the error.
// Log.i(TAG, "An error occurred: " + status);
autocom.setText(""+status+"");
}
});
}
/**
* Manipulates the map once available.
* This callback is triggered when the map is ready to be used.
* This is where we can add markers or lines, add listeners or move the camera. In this case,
* we just add a marker near Sydney, Australia.
* If Google Play services is not installed on the device, the user will be prompted to install
* it inside the SupportMapFragment. This method will only be triggered once the user has
* installed Google Play services and returned to the app.
*/
@Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
// Add a marker in Sydney and move the camera
LatLng sydney = new LatLng(-34, 151);
mMap.addMarker(new MarkerOptions().position(sydney).title("Marker in Sydney"));
mMap.moveCamera(CameraUpdateFactory.newLatLng(sydney));
}
}
autocom.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<android.support.v7.widget.CardView xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:id="@+id/card_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="top"
card_view:cardCornerRadius="4dp">
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/place_autocomplete_fragment"
android:name="com.google.android.gms.location.places.ui.PlaceAutocompleteFragment"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</android.support.v7.widget.CardView>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/autotv"/>
</LinearLayout>
activity_maps.xml
<fragment 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:id="@+id/map"
android:name="com.google.android.gms.maps.SupportMapFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.srinivas.mapautocompletetest1.MapsActivity" />
堆栈跟踪
03-02 13:10:45.665 14169-14169/com.example.srinivas.mapautocompletetest1 E/dalvikvm: Could not find class 'com.google.android.chimera.Activity', referenced from method mu.b
03-02 13:10:45.908 14169-14169/com.example.srinivas.mapautocompletetest1 E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.srinivas.mapautocompletetest1, PID: 14169
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.srinivas.mapautocompletetest1/com.example.srinivas.mapautocompletetest1.MapsActivity}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2338)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2390)
at android.app.ActivityThread.access$800(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1321)
at android.os.Handler.dispatchMessage(Handler.java:110)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:5292)
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:824)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:640)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.example.srinivas.mapautocompletetest1.MapsActivity.onCreate(MapsActivity.java:37)
at android.app.Activity.performCreate(Activity.java:5264)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1088)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2302)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2390)
at android.app.ActivityThread.access$800(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1321)
at android.os.Handler.dispatchMessage(Handler.java:110)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:5292)
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:824)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:640)
at dalvik.system.NativeStart.main(Native Method)
推荐答案
我通过在默认 google maps 布局文件和相同的Java文件中包含 autocomplete片段来解决了此问题像以前一样归档.我已经在下面发布了最终代码.
I solved this by including the autocomplete fragment inside the default google maps layout file and the same java file as before. I have posted the final code below.
activity_maps.xml
<LinearLayout android:layout_height="match_parent"
android:layout_width="match_parent"
android:orientation="vertical"
xmlns:android="http://schemas.android.com/apk/res/android" >
<fragment
android:id="@+id/place_autocomplete_fragment"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:name="com.google.android.gms.location.places.ui.PlaceAutocompleteFragment" />
<fragment
xmlns:map="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/map"
android:name="com.google.android.gms.maps.SupportMapFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.srinivas.democomplete.MapsActivity>
</LinearLayout>
这篇关于Google上的Java空指针异常放置片段的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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