菜单无法解析或不是字段。膨胀(R.menu.main,菜单)

时间:2014-05-08 10:53:17

标签: android xml r.java-file oncreateoptionsmenu

我知道这似乎是重复的,但事实并非如此。

我正在关注谷歌地图的教程,我无法解决这个问题(注意这是我第一次在Android上开发)。

在函数onCreateOptionsMenu中,我得到了我在标题中描述的错误。

这是我的MainActivity.java(onCreateOptionsMenu在底部):

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

import org.json.JSONObject;

import android.graphics.Color;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.util.Log;
import android.view.Menu;
import android.widget.TextView;
import android.widget.Toast;

import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.GoogleMap.OnMapClickListener;
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.MarkerOptions;
import com.google.android.gms.maps.model.PolylineOptions;

public class MainActivity extends FragmentActivity
{
GoogleMap map;
ArrayList<LatLng> markerPoints;
TextView tvDistanceDuration;

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

    TextView distancia_tiempo = new TextView(this);

    this.tvDistanceDuration = distancia_tiempo; //this.findViewById(R.id.tv_distance_time);
    // Initializing
    this.markerPoints = new ArrayList<LatLng>();

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

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

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

    // Setting onclick event listener for the map
    this.map.setOnMapClickListener(new OnMapClickListener()
    {
        @Override
        public void onMapClick(LatLng point)
        {
            // Already two locations
            if (MainActivity.this.markerPoints.size() > 1)
            {
                MainActivity.this.markerPoints.clear();
                MainActivity.this.map.clear();
            }

            // Adding new item to the ArrayList
            MainActivity.this.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 (MainActivity.this.markerPoints.size() == 1)
            {
                options.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_GREEN));
            } else if (MainActivity.this.markerPoints.size() == 2)
            {
                options.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_RED));
            }

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

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

                // Getting URL to the Google Directions API
                String url = MainActivity.this.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 = MainActivity.this.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(MainActivity.this.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 = point.get("distance");
                    continue;
                } else if (j == 1)
                { // Get duration from the list
                    duration = 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);
        }

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

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

@Override
public boolean onCreateOptionsMenu(Menu menu)
{
    // Inflate the menu; this adds items to the action bar if it is present.
    this.getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

}

这是activity_main.xml:

<MapFragment xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >

<fragment 
      android:id="@+id/map"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:name="com.google.android.gms.maps.MapFragment"/>
</MapFragment>

任何想法??

0 个答案:

没有答案