问题
I'm using google map v2 in my app but I get the blank page like this:
I did these stepe for adding this feature to my project.
First of all I updated google play services
Added
D:\AndroidSDK\extras\google\google_play_services\libproject\google-play-services_libas a dependency to my main project also the jar file in the libs folder of this path.Activated google map android APIs v2 in Google APIs Console
Created new Android key and the result is:
After those steps I added the API key into the manifest file:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.test"
android:versionCode="1"
android:versionName="1.0">
<uses-sdk android:minSdkVersion="8"
android:targetSdkVersion="17"/>
<permission
android:name="com.example.test.permission.MAPS_RECEIVE"
android:protectionLevel="signature"/>
<uses-permission android:name="com.example.test.permission.MAPS_RECEIVE/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES" />
<!-- External storage for caching. -->
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<!-- My Location -->
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.CALL_PHONE" />
<uses-permission android:name="android.permission.READ_PHONE_STATE" />
<!-- Maps API needs OpenGL ES 2.0. -->
<uses-feature
android:glEsVersion="0x00020000"
android:required="true" />
<!-- End of copy. -->
<application android:label="@string/app_name"
android:icon="@drawable/ic_launcher"
android:theme="@style/Theme.Sherlock.Light">
<activity android:name=".ActivityBusinessDirections"
android:label="@string/app_name">
<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="AIzaSyBmFPG-Fri--**************" />
</application>
</manifest>
And finally this is my layout that I use
<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"
android:layout_width="match_parent"
android:layout_height="match_parent"
class="com.google.android.gms.maps.SupportMapFragment"/>
</RelativeLayout>
EDIT: this is my activity code
public class ActivityBusinessDirections extends FragmentActivity implements LocationListener {
GoogleMap mGoogleMap;
ArrayList<LatLng> mMarkerPoints;
double mLatitude=0;
double mLongitude=0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_business_directions);
// Getting Google Play availability status
int status = GooglePlayServicesUtil.isGooglePlayServicesAvailable(getBaseContext());
if(status!=ConnectionResult.SUCCESS){ // Google Play Services are not available
int requestCode = 10;
Dialog dialog = GooglePlayServicesUtil.getErrorDialog(status, this, requestCode);
dialog.show();
}else { // Google Play Services are available
// Initializing
mMarkerPoints = new ArrayList<LatLng>();
// Getting reference to SupportMapFragment of the activity_main
SupportMapFragment fm = (SupportMapFragment)getSupportFragmentManager().findFragmentById(R.id.map);
// Getting Map for the SupportMapFragment
mGoogleMap = fm.getMap();
// Enable MyLocation Button in the Map
mGoogleMap.setMyLocationEnabled(true);
// Getting LocationManager object from System Service LOCATION_SERVICE
LocationManager locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
// Creating a criteria object to retrieve provider
Criteria criteria = new Criteria();
// Getting the name of the best provider
String provider = locationManager.getBestProvider(criteria, true);
// Getting Current Location From GPS
Location location = locationManager.getLastKnownLocation(provider);
if(location!=null){
onLocationChanged(location);
}
locationManager.requestLocationUpdates(provider, 20000, 0, this);
// Setting onclick event listener for the map
mGoogleMap.setOnMapClickListener(new OnMapClickListener() {
@Override
public void onMapClick(LatLng point) {
// Already map contain destination location
if(mMarkerPoints.size()>1){
FragmentManager fm = getSupportFragmentManager();
mMarkerPoints.clear();
mGoogleMap.clear();
LatLng startPoint = new LatLng(mLatitude, mLongitude);
// draw the marker at the current position
drawMarker(startPoint);
}
// draws the marker at the currently touched location
drawMarker(point);
// Checks, whether start and end locations are captured
if(mMarkerPoints.size() >= 2){
LatLng origin = mMarkerPoints.get(0);
LatLng dest = mMarkerPoints.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;
}
/** A class to download data from Google Directions URL */
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 Directions 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;
// 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);
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);
}
// Drawing polyline in the Google Map for the i-th route
mGoogleMap.addPolyline(lineOptions);
}
}
private void drawMarker(LatLng point){
mMarkerPoints.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(mMarkerPoints.size()==1){
options.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_GREEN));
}else if(mMarkerPoints.size()==2){
options.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_RED));
}
// Add new marker to the Google Map Android API V2
mGoogleMap.addMarker(options);
}
@Override
public void onLocationChanged(Location location) {
// Draw the marker, if destination location is not set
if(mMarkerPoints.size() < 2){
mLatitude = location.getLatitude();
mLongitude = location.getLongitude();
LatLng point = new LatLng(mLatitude, mLongitude);
mGoogleMap.moveCamera(CameraUpdateFactory.newLatLng(point));
mGoogleMap.animateCamera(CameraUpdateFactory.zoomTo(12));
drawMarker(point);
}
}
@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
}
}
回答1:
If you changed API key in manifest just
- clear data (in android device)
or
- uninstall app and reinstall it
回答2:
From the Manifest file you posted it looks like you package name: package="com.com.my_package_name"
does not match the package name you used for Google Maps permissions:
<permission
android:name="com.my_package_name.permission.MAPS_RECEIVE"
android:protectionLevel="signature"/>
<uses-permission android:name="com.my_package_name.permission.MAPS_RECEIVE/>
You can see that com.com.my_package_name is different from com.my_package_name, this must be your problem.
回答3:
Try to add this permission to to your manifest
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
回答4:
There are two keys debug and release key. If you signed your apk you want to use release key. I think you used debug key. So only map looks blank. Release key procedures are here.
How to get production key for google map?
回答5:
Make sure you are using the same SHA1 finger print in API console that your project built with, find your SHA1 finger print from eclipse Window>Preferences>Android>Build>SHA1 fingerprint.
来源：https://stackoverflow.com/questions/18498107/android-blank-page-when-using-google-map-api-2