Question

我是Android开发的新手。我正在尝试制作一个应用程序，其中列出了各种各样的广告。当某人点击其中一个项目时，将打开第二个布局，其中包含有关该项目的地图和信息：

我通过阅读json来获取列表和信息，我通过php脚本动态生成（这里没有问题）。我也从json获取该项目的地址，并尝试对该位置进行地理编码。我生成第一个布局没有错误，但是当我尝试进入第二个布局时，应用程序崩溃，看起来是地图中的零点异常。该应用程序没有map元素。这是一些代码：

来自主要活动：

@Override
    protected void onPostExecute(final List<AdModels> s) {
        super.onPostExecute(s);
        dialog.dismiss();
        if(s != null) {
            AdAdapter adapter = new AdAdapter(getApplicationContext(), R.layout.row, s);
            lvAds.setAdapter(adapter);
            lvAds.setOnItemClickListener(new AdapterView.OnItemClickListener() {
                @Override
                public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                    AdModels admodel = s.get(position);
                    Intent intent = new Intent(MainActivity.this, MapsActivity.class);
                    intent.putExtra("adInfo", new Gson().toJson(admodel));
                    startActivity(intent);
                }
            });
        } else {
            Toast.makeText(getApplicationContext(), "Not able to fetch data from server, please check url.", Toast.LENGTH_SHORT);
        }
    }

这是MapsActivity

package dk.forsoegsperson.fp;

import android.location.Address;
import android.location.Geocoder;
import android.support.v4.app.FragmentActivity;
import android.os.Bundle;
import android.text.Html;
import android.view.MenuItem;
import android.webkit.WebView;
import android.widget.TextView;

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;
import com.google.gson.Gson;

import java.io.IOException;
import java.util.List;
import java.util.Locale;

import dk.forsoegsperson.fp.Models.AdModels;

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {

    private GoogleMap mMap;

    private TextView overskrift;
    private TextView navn;
    private TextView tlf;
    private TextView email;
    private TextView intro;
    private WebView annonce;

    String forsoeg_address;
    String forsoeg_over;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_detail);
        // 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);

        // setting up text views and stuff
        setUpUIViews();

        Bundle bundle = getIntent().getExtras();
        if(bundle != null){

            String json = bundle.getString("adInfo");
            AdModels admodel = new Gson().fromJson(json, AdModels.class);

            forsoeg_address = admodel.getAddress();
            forsoeg_over = admodel.getOverskrift();
            String coded_ad = admodel.getAnnonce();
            String decoded_ad = Html.fromHtml(coded_ad).toString();

            overskrift.setText(admodel.getOverskrift());
            intro.setText(admodel.getIntro());
            navn.setText(admodel.getNavn());
            email.setText(admodel.getEmail());
            tlf.setText("Tlf: " + admodel.getTlf());
            annonce.loadData(decoded_ad,  "text/html; charset=UTF-8", null);
        }

    }

    private void setUpUIViews() {
        overskrift = (TextView)findViewById(R.id.dOverskrift);
        navn = (TextView)findViewById(R.id.dNavn);
        tlf = (TextView)findViewById(R.id.dTlf);
        email = (TextView)findViewById(R.id.dEmail);
        intro = (TextView)findViewById(R.id.dIntro);
        annonce = (WebView)findViewById(R.id.dAnnonce);
    }

    @Override
    public void onMapReady(GoogleMap googleMap) {

        GoogleMap mMap = googleMap;

        Geocoder geocoder = new Geocoder(this, Locale.getDefault());
        if (forsoeg_address != null && forsoeg_address != "") {
            try {
                List<Address> addressList = geocoder.getFromLocationName(forsoeg_address, 1);
                if (addressList != null && addressList.size() > 0) {
                    Address addres_loc = addressList.get(0);
                    LatLng pt = new LatLng(addres_loc.getLatitude(), addres_loc.getLongitude());
                    mMap.addMarker(new MarkerOptions().position(pt).title(forsoeg_over));
                    mMap.moveCamera(CameraUpdateFactory.newLatLng(pt));;
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        else {
            LatLng pt = new LatLng(56.2639, 9.5018);
            mMap.addMarker(new MarkerOptions().position(pt).title(forsoeg_over));
            mMap.moveCamera(CameraUpdateFactory.newLatLng(pt));
        } 
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == android.R.id.home) {
            finish();
        }
        return super.onOptionsItemSelected(item);
    }
}

这是activity_detail的xml;

<?xml version="1.0" encoding="utf-8"?>
<ScrollView  xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
    <fragment
        android:id="@+id/map"
        xmlns:tools="http://schemas.android.com/tools"
        android:name="com.google.android.gms.maps.MapFragment"
        android:layout_width="match_parent"
        android:layout_height="150dp"
        tools:context="dk.forsoegsperson.fp.MapsActivity"/>
    <TextView
        android:textSize="18dp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/dOverskrift"
        android:layout_alignParentTop="true"
        android:layout_marginTop="160dp"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="10dp"
        android:divider="@null"
        android:dividerHeight="0dp"/>
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/dIntro"
        android:layout_below="@+id/dOverskrift"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="10dp"
        android:divider="@null"
        android:dividerHeight="0dp"/> 
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/dNavn"
        android:layout_below="@+id/dIntro"
        android:layout_centerHorizontal="true"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="10dp"
        android:divider="@null"
        android:dividerHeight="0dp"/>   
    <TextView
        android:autoLink="email"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/dEmail"
        android:layout_below="@+id/dNavn"
        android:layout_centerHorizontal="true"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="10dp"
        android:divider="@null"
        android:dividerHeight="0dp"/>    
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/dTlf"
        android:layout_below="@+id/dEmail"
        android:layout_centerHorizontal="true"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="10dp"
        android:divider="@null"
        android:dividerHeight="0dp"/>    
    <WebView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/dAnnonce"
        android:layout_below="@+id/dTlf"
        android:layout_centerHorizontal="true"
        android:divider="@null"
        android:dividerHeight="0dp"/>
    </RelativeLayout>
</ScrollView>

这是清单：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="dk.forsoegsperson.fp"> 
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme">
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name=".detail" />
        <meta-data
            android:name="com.google.android.geo.API_KEY"
            android:value="@string/google_maps_key" />
        <activity
            android:name=".MapsActivity"
            android:label="@string/title_activity_detail"></activity>
    </application>
</manifest>

错误日志：

        07-22 09:09:29.478 2789-2971/dk.forsoegsperson.fp E/Surface: getSlotFromBufferLocked: unknown buffer: 0xa073c340
  07-22 09:09:36.693 2789-2789/dk.forsoegsperson.fp E/SysUtils: ApplicationContext is null in ApplicationStatus
  07-22 09:09:36.892 2789-2789/dk.forsoegsperson.fp E/libEGL: validate_display:255 error 3008 (EGL_BAD_DISPLAY)
  07-22 09:09:36.892 2789-2789/dk.forsoegsperson.fp E/libEGL: validate_display:255 error 3008 (EGL_BAD_DISPLAY)
  07-22 09:09:37.071 2789-2789/dk.forsoegsperson.fp E/DataReductionProxySettingListener: No DRP key due to exception:java.lang.ClassNotFoundException: com.android.webview.chromium.Drp
  07-22 09:09:37.352 2789-2789/dk.forsoegsperson.fp E/AndroidRuntime: FATAL EXCEPTION: main
                                                                      Process: dk.forsoegsperson.fp, PID: 2789
                                                                      java.lang.RuntimeException: Unable to start activity ComponentInfo{dk.forsoegsperson.fp/dk.forsoegsperson.fp.MapsActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void com.google.android.gms.maps.SupportMapFragment.getMapAsync(com.google.android.gms.maps.OnMapReadyCallback)' on a null object reference
                                                                          at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416)
                                                                          at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
                                                                          at android.app.ActivityThread.-wrap11(ActivityThread.java)
                                                                          at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
                                                                          at android.os.Handler.dispatchMessage(Handler.java:102)
                                                                          at android.os.Looper.loop(Looper.java:148)
                                                                          at android.app.ActivityThread.main(ActivityThread.java:5417)
                                                                          at java.lang.reflect.Method.invoke(Native Method)
                                                                          at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
                                                                          at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
                                                                       Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void com.google.android.gms.maps.SupportMapFragment.getMapAsync(com.google.android.gms.maps.OnMapReadyCallback)' on a null object reference
                                                                          at dk.forsoegsperson.fp.MapsActivity.onCreate(MapsActivity.java:51)
                                                                          at android.app.Activity.performCreate(Activity.java:6237)
                                                                          at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
                                                                          at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)
                                                                          at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476) 
                                                                          at android.app.ActivityThread.-wrap11(ActivityThread.java) 
                                                                          at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344) 
                                                                          at android.os.Handler.dispatchMessage(Handler.java:102) 
                                                                          at android.os.Looper.loop(Looper.java:148) 
                                                                          at android.app.ActivityThread.main(ActivityThread.java:5417) 
                                                                          at java.lang.reflect.Method.invoke(Native Method) 
                                                                          at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
                                                                          at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

我好几天都在看这个。为什么应用程序崩溃了？请注意，我只在模拟器上运行此功能，并为此软件包提供了正确的Google API密钥。

（编辑：添加错误日志）

Answer 1

将xml文件代码更改为：

<fragment
        android:id="@+id/map"
        xmlns:tools="http://schemas.android.com/tools"
        android:name="com.google.android.gms.maps.SupportMapFragment"
        android:layout_width="match_parent"
        android:layout_height="150dp"
        tools:context="dk.forsoegsperson.fp.MapsActivity"/>

我将MapFragment更改为SupportMapFragment类

Android地图因空点异常而崩溃

1 个答案: