java - Google Map Android API V2 中两个位置之间的行驶距离和旅行持续时间

Question

我正在尝试在 android studio 中实现这个例子: driving distance and travel time duration between two locations

我在运行时遇到如下错误:

E/GMPM: getGoogleAppId failed with status: 10
E/GMPM: Uploading is not possible. App measurement disabled
D/AndroidRuntime: Shutting down VM
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.start.yogeshp.location, PID: 7332
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.start.yogeshp.location/com.start.yogeshp.location.MainActivity}: android.view.InflateException: Binary XML file line #19: Error inflating class fragment
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
at android.app.ActivityThread.access$800(ActivityThread.java:144)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
Caused by: android.view.InflateException: Binary XML file line #19: Error inflating class fragment
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:763)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:806)
at android.view.LayoutInflater.inflate(LayoutInflater.java:504)
at android.view.LayoutInflater.inflate(LayoutInflater.java:414)
at android.view.LayoutInflater.inflate(LayoutInflater.java:365)
at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:377)
at android.app.Activity.setContentView(Activity.java:2144)
at com.start.yogeshp.location.MainActivity.onCreate(MainActivity.java:40)
at android.app.Activity.performCreate(Activity.java:5937)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360) 
at android.app.ActivityThread.access$800(ActivityThread.java:144) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:135) 
at android.app.ActivityThread.main(ActivityThread.java:5221) 
at java.lang.reflect.Method.invoke(Native Method) 
at java.lang.reflect.Method.invoke(Method.java:372) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694) 
Caused by: java.lang.NullPointerException
at java.lang.VMClassLoader.findLoadedClass(Native Method)
at java.lang.ClassLoader.findLoadedClass(ClassLoader.java:362)
at java.lang.ClassLoader.loadClass(ClassLoader.java:499)
at java.lang.ClassLoader.loadClass(ClassLoader.java:469)
at android.support.v4.app.Fragment.isSupportFragmentClass(Fragment.java:457)
at android.support.v4.app.FragmentManagerImpl.onCreateView(FragmentManager.java:2248)
at android.support.v4.app.FragmentController.onCreateView(FragmentController.java:111)
at android.support.v4.app.FragmentActivity.dispatchFragmentsOnCreateView(FragmentActivity.java:314)
at android.support.v4.app.BaseFragmentActivityHoneycomb.onCreateView(BaseFragmentActivityHoneycomb.java:31)
at android.support.v4.app.FragmentActivity.onCreateView(FragmentActivity.java:79)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:733)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:806) 
at android.view.LayoutInflater.inflate(LayoutInflater.java:504) 
at android.view.LayoutInflater.inflate(LayoutInflater.java:414) 
at android.view.LayoutInflater.inflate(LayoutInflater.java:365) 
at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:377) 
at android.app.Activity.setContentView(Activity.java:2144) 
at com.start.yogeshp.location.MainActivity.onCreate(MainActivity.java:40) 
at android.app.Activity.performCreate(Activity.java:5937) 
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105) 
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251) 
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360) 
at android.app.ActivityThread.access$800(ActivityThread.java:144) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:135) 
at android.app.ActivityThread.main(ActivityThread.java:5221) 
at java.lang.reflect.Method.invoke(Native Method) 
at java.lang.reflect.Method.invoke(Method.java:372) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694) 

这些是我的文件:

MainActivity.java

    public class MainActivity extends FragmentActivity {

GoogleMap map;
ArrayList<LatLng> markerPoints;
TextView tvDistanceDuration;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    tvDistanceDuration = (TextView) findViewById(R.id.tv_distance_time);

    // Initializing
    markerPoints = new ArrayList<LatLng>();

    // Getting reference to SupportMapFragment of the activity_main
    SupportMapFragment fm = (SupportMapFragment)getSupportFragmentManager().findFragmentById(R.id.map);

    // Getting Map for the SupportMapFragment
    map = fm.getMap();

    // Enable MyLocation Button in the Map
    map.setMyLocationEnabled(true);

    // Setting onclick event listener for the map
    map.setOnMapClickListener(new OnMapClickListener() {

        @Override
        public void onMapClick(LatLng point) {

            // Already two locations
            if(markerPoints.size()>1){
                markerPoints.clear();
                map.clear();
            }

            // Adding new item to the ArrayList
            markerPoints.add(point);

            // Creating MarkerOptions
            MarkerOptions options = new MarkerOptions();

            // Setting the position of the marker
            options.position(point);

            /**
             * For the start location, the color of marker is GREEN and
             * for the end location, the color of marker is RED.
             */
            if(markerPoints.size()==1){
                options.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_GREEN));
            }else if(markerPoints.size()==2){
                options.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_RED));
            }

            // Add new marker to the Google Map Android API V2
            map.addMarker(options);

            // Checks, whether start and end locations are captured
            if(markerPoints.size() >= 2){
                LatLng origin = markerPoints.get(0);
                LatLng dest = markerPoints.get(1);

                // Getting URL to the Google Directions API
                String url = getDirectionsUrl(origin, dest);

                DownloadTask downloadTask = new DownloadTask();

                // Start downloading json data from Google Directions API
                downloadTask.execute(url);
            }
        }
    });
}

private String getDirectionsUrl(LatLng origin,LatLng dest){

    // Origin of route
    String str_origin = "origin="+origin.latitude+","+origin.longitude;

    // Destination of route
    String str_dest = "destination="+dest.latitude+","+dest.longitude;

    // Sensor enabled
    String sensor = "sensor=false";

    // Building the parameters to the web service
    String parameters = str_origin+"&"+str_dest+"&"+sensor;

    // Output format
    String output = "json";

    // Building the url to the web service
    String url = "https://maps.googleapis.com/maps/api/directions/"+output+"?"+parameters;

    return url;
}

/** A method to download json data from url */
private String downloadUrl(String strUrl) throws IOException{
    String data = "";
    InputStream iStream = null;
    HttpURLConnection urlConnection = null;
    try{
        URL url = new URL(strUrl);

        // Creating an http connection to communicate with url
        urlConnection = (HttpURLConnection) url.openConnection();

        // Connecting to url
        urlConnection.connect();

        // Reading data from url
        iStream = urlConnection.getInputStream();

        BufferedReader br = new BufferedReader(new InputStreamReader(iStream));

        StringBuffer sb  = new StringBuffer();

        String line = "";
        while( ( line = br.readLine())  != null){
            sb.append(line);
        }

        data = sb.toString();

        br.close();

    }catch(Exception e){
        Log.d("Exception while downloading url", e.toString());
    }finally{
        iStream.close();
        urlConnection.disconnect();
    }
    return data;
}

// Fetches data from url passed
private class DownloadTask extends AsyncTask<String, Void, String>{

    // Downloading data in non-ui thread
    @Override
    protected String doInBackground(String... url) {

        // For storing data from web service
        String data = "";

        try{
            // Fetching the data from web service
            data = downloadUrl(url[0]);
        }catch(Exception e){
            Log.d("Background Task",e.toString());
        }
        return data;
    }

    // Executes in UI thread, after the execution of
    // doInBackground()
    @Override
    protected void onPostExecute(String result) {
        super.onPostExecute(result);

        ParserTask parserTask = new ParserTask();

        // Invokes the thread for parsing the JSON data
        parserTask.execute(result);
    }
}

/** A class to parse the Google Places in JSON format */
private class ParserTask extends AsyncTask<String, Integer, List<List<HashMap<String,String>>> >{

    // Parsing the data in non-ui thread
    @Override
    protected List<List<HashMap<String, String>>> doInBackground(String... jsonData) {

        JSONObject jObject;
        List<List<HashMap<String, String>>> routes = null;

        try{
            jObject = new JSONObject(jsonData[0]);
            DirectionsJSONParser parser = new DirectionsJSONParser();

            // Starts parsing data
            routes = parser.parse(jObject);
        }catch(Exception e){
            e.printStackTrace();
        }
        return routes;
    }

    // Executes in UI thread, after the parsing process
    @Override
    protected void onPostExecute(List<List<HashMap<String, String>>> result) {
        ArrayList<LatLng> points = null;
        PolylineOptions lineOptions = null;
        MarkerOptions markerOptions = new MarkerOptions();
        String distance = "";
        String duration = "";

        if(result.size()<1){
            Toast.makeText(getBaseContext(), "No Points", Toast.LENGTH_SHORT).show();
            return;
        }

        // Traversing through all the routes
        for(int i=0;i<result.size();i++){
            points = new ArrayList<LatLng>();
            lineOptions = new PolylineOptions();

            // Fetching i-th route
            List<HashMap<String, String>> path = result.get(i);

            // Fetching all the points in i-th route
            for(int j=0;j<path.size();j++){
                HashMap<String,String> point = path.get(j);

                if(j==0){    // Get distance from the list
                    distance = (String)point.get("distance");
                    continue;
                }else if(j==1){ // Get duration from the list
                    duration = (String)point.get("duration");
                    continue;
                }

                double lat = Double.parseDouble(point.get("lat"));
                double lng = Double.parseDouble(point.get("lng"));
                LatLng position = new LatLng(lat, lng);

                points.add(position);
            }

            // Adding all the points in the route to LineOptions
            lineOptions.addAll(points);
            lineOptions.width(2);
            lineOptions.color(Color.RED);
        }

        tvDistanceDuration.setText("Distance:"+distance + ", Duration:"+duration);

        // Drawing polyline in the Google Map for the i-th route
        map.addPolyline(lineOptions);
    }
} }

DirectionsJSONParser.java:

    public class DirectionsJSONParser {

/** Receives a JSONObject and returns a list of lists containing latitude and longitude */
public List<List<HashMap<String,String>>> parse(JSONObject jObject){

    List<List<HashMap<String, String>>> routes = new ArrayList<List<HashMap<String,String>>>() ;
    JSONArray jRoutes = null;
    JSONArray jLegs = null;
    JSONArray jSteps = null;
    JSONObject jDistance = null;
    JSONObject jDuration = null;

    try {

        jRoutes = jObject.getJSONArray("routes");

        /** Traversing all routes */
        for(int i=0;i<jRoutes.length();i++){
            jLegs = ( (JSONObject)jRoutes.get(i)).getJSONArray("legs");

            List<HashMap<String, String>> path = new ArrayList<HashMap<String, String>>();

            /** Traversing all legs */
            for(int j=0;j<jLegs.length();j++){

                /** Getting distance from the json data */
                jDistance = ((JSONObject) jLegs.get(j)).getJSONObject("distance");
                HashMap<String, String> hmDistance = new HashMap<String, String>();
                hmDistance.put("distance", jDistance.getString("text"));

                /** Getting duration from the json data */
                jDuration = ((JSONObject) jLegs.get(j)).getJSONObject("duration");
                HashMap<String, String> hmDuration = new HashMap<String, String>();
                hmDuration.put("duration", jDuration.getString("text"));

                /** Adding distance object to the path */
                path.add(hmDistance);

                /** Adding duration object to the path */
                path.add(hmDuration);

                jSteps = ( (JSONObject)jLegs.get(j)).getJSONArray("steps");

                /** Traversing all steps */
                for(int k=0;k<jSteps.length();k++){
                    String polyline = "";
                    polyline = (String)((JSONObject)((JSONObject)jSteps.get(k)).get("polyline")).get("points");
                    List<LatLng> list = decodePoly(polyline);

                    /** Traversing all points */
                    for(int l=0;l<list.size();l++){
                        HashMap<String, String> hm = new HashMap<String, String>();
                        hm.put("lat", Double.toString(((LatLng)list.get(l)).latitude) );
                        hm.put("lng", Double.toString(((LatLng)list.get(l)).longitude) );
                        path.add(hm);
                    }
                }
            }
            routes.add(path);
        }
    } catch (JSONException e) {
        e.printStackTrace();
    }catch (Exception e){
    }
    return routes;
}

/**
 * Method to decode polyline points
 * Courtesy : jeffreysambells.com/2010/05/27/decoding-polylines-from-google-maps-direction-api-with-java
 * */
private List<LatLng> decodePoly(String encoded) {

    List<LatLng> poly = new ArrayList<LatLng>();
    int index = 0, len = encoded.length();
    int lat = 0, lng = 0;

    while (index < len) {
        int b, shift = 0, result = 0;
        do {
            b = encoded.charAt(index++) - 63;
            result |= (b & 0x1f) << shift;
            shift += 5;
        } while (b >= 0x20);
        int dlat = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
        lat += dlat;

        shift = 0;
        result = 0;
        do {
            b = encoded.charAt(index++) - 63;
            result |= (b & 0x1f) << shift;
            shift += 5;
        } while (b >= 0x20);
        int dlng = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
        lng += dlng;

        LatLng p = new LatLng((((double) lat / 1E5)),
                (((double) lng / 1E5)));
        poly.add(p);
    }
    return poly;
} }

activity_main.xml:

我在相对布局中使用了两个字段:

     <TextView
    android:id="@+id/tv_distance_time"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/hello_world"
    android:layout_alignParentTop="true" />

<fragment
    android:id="@+id/map"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@id/tv_distance_time" />

AndroidManifest.xml:

<?xml version="1.0" encoding="utf-8"?>

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<permission
    android:name="com.start.yogeshp.location.permission.MAPS_RECEIVE"
    android:protectionLevel="signature" />

<uses-permission android:name="com.start.yogeshp.location.permission.MAPS_RECEIVE" />

<uses-feature
    android:glEsVersion="0x00020000"
    android:required="true"/>
<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">
    <activity android:name=".MainActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <meta-data
        android:name="com.google.android.maps.v2.API_KEY"
        android:value="key" />

</application>

最后将“compile 'com.google.android.gms:play-services:8.3.0'”添加到我的 build.gradle 文件中。

Answer 1

在布局中您忘记了 class 属性

<fragment 
class="com.google.android.gms.maps.SupportMapFragment" 
android:id="@+id/map"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@id/tv_distance_time">