您好我是Android编程的新手。在这里，我根据从当前位置到所选城市的距离进行计算出租车费用的简单项目。 但是我收到了错误。
这是我的 map.xml 文件
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".Maps" >
<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_alignParentBottom="true"
android:layout_below="@id/tv_distance_time"
class="com.google.android.gms.maps.SupportMapFragment" />
这是我的 Maps.java 类
package com.example.mainproject;
import com.example.mainproject.R;
import com.example.mainproject.Maps.DownloadTask;
import com.example.mainproject.DirectionsJSONParser;
import com.example.mainproject.Maps.ParserTask;
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 com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.GoogleMap.OnMapClickListener;
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;
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;
public class Maps extends FragmentActivity {
GoogleMap map;
ArrayList<LatLng> markerPoints;
TextView tvDistanceDuration;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.map);
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
public 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 */
public 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);
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
这是我的LogCat文件错误..
10-29 10:52:00.144: E/AndroidRuntime(1777): FATAL EXCEPTION: main
10-29 10:52:00.144: E/AndroidRuntime(1777): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.mainproject/com.example.mainproject.Maps}: android.view.InflateException: Binary XML file line #15: Error inflating class fragment
10-29 10:52:00.144: E/AndroidRuntime(1777): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
10-29 10:52:00.144: E/AndroidRuntime(1777): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
10-29 10:52:00.144: E/AndroidRuntime(1777): at android.app.ActivityThread.access$600(ActivityThread.java:141)
10-29 10:52:00.144: E/AndroidRuntime(1777): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
10-29 10:52:00.144: E/AndroidRuntime(1777): at android.os.Handler.dispatchMessage(Handler.java:99)
10-29 10:52:00.144: E/AndroidRuntime(1777): at android.os.Looper.loop(Looper.java:137)
10-29 10:52:00.144: E/AndroidRuntime(1777): at android.app.ActivityThread.main(ActivityThread.java:5039)
10-29 10:52:00.144: E/AndroidRuntime(1777): at java.lang.reflect.Method.invokeNative(Native Method)
10-29 10:52:00.144: E/AndroidRuntime(1777): at java.lang.reflect.Method.invoke(Method.java:511)
10-29 10:52:00.144: E/AndroidRuntime(1777): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
10-29 10:52:00.144: E/AndroidRuntime(1777): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
10-29 10:52:00.144: E/AndroidRuntime(1777): at dalvik.system.NativeStart.main(Native Method)
10-29 10:52:00.144: E/AndroidRuntime(1777): Caused by: android.view.InflateException: Binary XML file line #15: Error inflating class fragment
10-29 10:52:00.144: E/AndroidRuntime(1777): at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:704)
请帮助我，并建议当前位置和gps跟踪器的代码..