我不知道为什么，但我无法获得 GPS 位置...
lm.getLastKnownLocation总是返回 null 并且onLocationChanged永远不会被调用。但我可以在系统托盘上看到 gps 图标。
有任何想法吗？
package com.localfotos;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONException;
import org.json.JSONObject;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.Handler;
import android.service.wallpaper.WallpaperService;
import android.util.Log;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
/*
* This animated wallpaper draws a rotating wireframe cube.
*/
public class MyWallpaperService extends WallpaperService implements LocationListener{
private final String TAG = "WallpaperService============================";
private LocationManager lm;
private final Handler mHandler = new Handler();
@Override
public void onLocationChanged(Location location) {
Log.d(TAG, "got location!");
}
@Override
public void onProviderDisabled(String provider) {
// TODO Auto-generated method stub
}
@Override
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
}
@Override
public void onCreate() {
lm = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1000, 0, this);
super.onCreate();
}
@Override
public void onDestroy() {
super.onDestroy();
lm.removeUpdates(this);
}
@Override
public Engine onCreateEngine() {
return new CubeEngine(this);
}
class CubeEngine extends Engine{
MyWallpaperService mws;
private final Runnable mDrawCube = new Runnable() {
public void run() {
drawFrame();
}
};
private boolean mVisible;
private double lat = -1;
private double lon = -1;
CubeEngine(MyWallpaperService mymws) {
mws = mymws;
}
@Override
public void onDestroy() {
super.onDestroy();
mHandler.removeCallbacks(mDrawCube);
}
@Override
public void onVisibilityChanged(boolean visible) {
mVisible = visible;
if (visible) {
drawFrame();
} else {
mHandler.removeCallbacks(mDrawCube);
}
}
@Override
public void onSurfaceChanged(SurfaceHolder holder, int format, int width, int height) {
super.onSurfaceChanged(holder, format, width, height);
drawFrame();
}
@Override
public void onSurfaceCreated(SurfaceHolder holder) {
super.onSurfaceCreated(holder);
}
@Override
public void onSurfaceDestroyed(SurfaceHolder holder) {
super.onSurfaceDestroyed(holder);
mVisible = false;
mHandler.removeCallbacks(mDrawCube);
}
@Override
public void onOffsetsChanged(float xOffset, float yOffset,
float xStep, float yStep, int xPixels, int yPixels) {
drawFrame();
}
/*
* Store the position of the touch event so we can use it for drawing later
*/
@Override
public void onTouchEvent(MotionEvent event) {
super.onTouchEvent(event);
}
/*
* Draw one frame of the animation. This method gets called repeatedly
* by posting a delayed Runnable. You can do any drawing you want in
* here. This example draws a wireframe cube.
*/
void drawFrame() {
final SurfaceHolder holder = getSurfaceHolder();
Canvas c = null;
try {
c = holder.lockCanvas();
if (c != null) {
// draw something
drawCube(c);
}
} finally {
if (c != null) holder.unlockCanvasAndPost(c);
}
// Reschedule the next redraw
mHandler.removeCallbacks(mDrawCube);
if (mVisible) {
mHandler.postDelayed(mDrawCube, 1000 * 10);
}
}
/*
* Draw a wireframe cube by drawing 12 3 dimensional lines between
* adjacent corners of the cube
*/
//taken from http://p-xr.com/android-tutorial-how-to-parse-read-json-data-into-a-android-listview/
private JSONObject getJSONfromURL(String url){
//initialize
InputStream is = null;
String result = "";
JSONObject jArray = null;
//http post
try{
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(url);
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
}catch(Exception e){
Log.e("log_tag", "Error in http connection "+e.toString());
}
//convert response to string
try{
BufferedReader reader = new BufferedReader(new InputStreamReader(is,"iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
result=sb.toString();
}catch(Exception e){
Log.e("log_tag", "Error converting result "+e.toString());
}
//try parse the string to a JSON object
try{
jArray = new JSONObject(result);
}catch(JSONException e){
Log.e("log_tag", "Error parsing data "+e.toString());
}
return jArray;
}
String getPanoramioUrl(double minx, double maxx, double maxy, double miny){
return "http://www.panoramio.com" +
"/map/get_panoramas.php?" +
"set=public&from=0&to=1&minx="+minx+"&miny="+miny+"&maxx="+maxx+"&maxy="+maxy;
}
void drawCube(Canvas canvas) {
//canvas.save();
//canvas.translate(0, 0);
//c.drawColor(0xff00aa00);
Location loc = mws.lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
try{
if (lat == loc.getLatitude() && lon == loc.getLongitude()){
return;
}
}catch(NullPointerException exc){
Log.d(TAG, "gps not ready");
return;
}
lat = loc.getLatitude();
lon = loc.getLongitude();
}
}
}
<application android:icon="@drawable/icon" android:label="@string/app_name">
<service android:name=".MyWallpaperService"
android:label="@string/app_name"
android:icon="@drawable/icon"
android:permission="android.permission.BIND_WALLPAPER">
<intent-filter>
<action android:name="android.service.wallpaper.WallpaperService" />
</intent-filter>
<meta-data android:name="android.service.wallpaper"
android:resource="@xml/livewallpaper" />
</service>
</application>