我想在谷歌地图v2上显示多个标记，也可以使用跳转动画点击动画标记。
/**
* This shows how to place markers on a map.
*/
public class Map extends FragmentActivity implements
OnMarkerClickListener,
OnInfoWindowClickListener,
OnMarkerDragListener {
static LatLng[] GEOPOINTS;
Map con;
ArrayList<Article> mArticles;
DBHelper helper;
Drawable marker;
Button search, cancel;
EditText search_value;
Button clear_search;
int activity_flag=0;
double slat, vlong;
/**
* Demonstrates customizing the info window and/or its contents.
*/
class CustomInfoWindowAdapter implements InfoWindowAdapter {
private final RadioGroup mOptions;
// These a both viewgroups containing an ImageView with id "badge" and two TextViews with id
// "title" and "snippet".
private final View mWindow;
private final View mContents;
CustomInfoWindowAdapter() {
mWindow = getLayoutInflater().inflate(R.layout.custom_info_window, null);
mContents = getLayoutInflater().inflate(R.layout.custom_info_contents, null);
mOptions = (RadioGroup) findViewById(R.id.custom_info_window_options);
}
@Override
public View getInfoWindow(Marker marker) {
if (mOptions.getCheckedRadioButtonId() != R.id.custom_info_window) {
// This means that getInfoContents will be called.
return null;
}
render(marker, mWindow);
return mWindow;
}
@Override
public View getInfoContents(Marker marker) {
if (mOptions.getCheckedRadioButtonId() != R.id.custom_info_contents) {
// This means that the default info contents will be used.
return null;
}
render(marker, mContents);
return mContents;
}
private void render(Marker marker, View view) {
int badge;
badge = R.drawable.badge_qld;
((ImageView) view.findViewById(R.id.badge)).setImageResource(badge);
String title = marker.getTitle();
TextView titleUi = ((TextView) view.findViewById(R.id.title));
if (title != null) {
// Spannable string allows us to edit the formatting of the text.
SpannableString titleText = new SpannableString(title);
titleText.setSpan(new ForegroundColorSpan(Color.RED), 0, titleText.length(), 0);
titleUi.setText(titleText);
} else {
titleUi.setText("");
}
String snippet = marker.getSnippet();
TextView snippetUi = ((TextView) view.findViewById(R.id.snippet));
if (snippet != null && snippet.length() > 12) {
SpannableString snippetText = new SpannableString(snippet);
snippetText.setSpan(new ForegroundColorSpan(Color.MAGENTA), 0, 10, 0);
snippetText.setSpan(new ForegroundColorSpan(Color.BLUE), 12, snippet.length(), 0);
snippetUi.setText(snippetText);
} else {
snippetUi.setText("");
}
}
}
private GoogleMap mMap;
private Marker[] marks;
private TextView mTopText;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.marker_demo);
con=this;
mTopText = (TextView) findViewById(R.id.top_text);
new loadingTask().execute();
}
@Override
protected void onResume() {
super.onResume();
setUpMapIfNeeded();
}
private void setUpMapIfNeeded() {
// Do a null check to confirm that we have not already instantiated the map.
if (mMap == null) {
// Try to obtain the map wrap the SupportMapFragment.
mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map)).getPolarisMap();
// Check if we were successful in obtaining the map.
if (mMap != null) {
setUpMap();
}
}
}
private void setUpMap() {
// Hide the zoom controls as the button panel will cover it.
mMap.getUiSettings().setZoomControlsEnabled(false);
// Add lots of markers to the map.
addMarkersToMap();
// Setting an info window adapter allows us to change the both the contents and look of the
// info window.
mMap.setInfoWindowAdapter(new CustomInfoWindowAdapter());
// Set listeners for marker events. See the bottom of this class for their behavior.
mMap.setOnMarkerClickListener(this);
mMap.setOnInfoWindowClickListener(this);
mMap.setOnMarkerDragListener(this);
// Pan to see all markers in view.
// Cannot zoom to bounds until the map has a size.
final View mapView = getSupportFragmentManager().findFragmentById(R.id.map).getView();
if (mapView.getViewTreeObserver().isAlive()) {
mapView.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
@SuppressWarnings("deprecation") // We use the new method when supported
@SuppressLint("NewApi") // We check which build version we are using.
@Override
public void onGlobalLayout() {
LatLngBounds bounds = new LatLngBounds.Builder().include(GEOPOINTS[0]).build();
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN) {
mapView.getViewTreeObserver().removeGlobalOnLayoutListener(this);
} else {
mapView.getViewTreeObserver().removeOnGlobalLayoutListener(this);
}
mMap.moveCamera(CameraUpdateFactory.newLatLngBounds(bounds, 50));
}
});
}
}
private void addMarkersToMap() {
// Uses a colored icon.
for (int i=0;i<mArticles.size();i++){
String latt=mArticles.get(i).latitude.trim().replace(",","");
String lonn=mArticles.get(i).longitude.trim();
//set latitude and longitude
GEOPOINTS[i] = new LatLng(Double.valueOf(latt), Double.valueOf(lonn));
marks[i] = mMap.addMarker(new MarkerOptions()
.position(GEOPOINTS[i])
.title(mArticles.get(i).enseigne)
.snippet(mArticles.get(i).type)
.icon(BitmapDescriptorFactory.fromResource(R.drawable.arrow)));
}
}
private boolean checkReady() {
if (mMap == null) {
Toast.makeText(this, R.string.map_not_ready, Toast.LENGTH_SHORT).show();
return false;
}
return true;
}
/**
* Called when the Clear button is clicked.
*/
public void onClearMap(View view) {
if (!checkReady()) {
return;
}
mMap.clear();
}
/**
* Called when the Reset button is clicked.
*/
public void onResetMap(View view) {
if (!checkReady()) {
return;
}
// Clear the map because we don't want duplicates of the markers.
mMap.clear();
addMarkersToMap();
}
//
// Marker related listeners.
//
@Override
public boolean onMarkerClick(final Marker marker) {
// This causes the marker at Perth to bounce into position when it is clicked.
final Handler handler = new Handler();
final long start = SystemClock.uptimeMillis();
Projection proj = mMap.getProjection();
Point startPoint = proj.toScreenLocation(GEOPOINTS[0]);
startPoint.offset(0, -100);
final LatLng startLatLng = proj.fromScreenLocation(startPoint);
final long duration = 1500;
final Interpolator interpolator = new BounceInterpolator();
handler.post(new Runnable() {
@Override
public void run() {
long elapsed = SystemClock.uptimeMillis() - start;
float t = interpolator.getInterpolation((float) elapsed / duration);
double lng = t * GEOPOINTS[0].longitude + (1 - t) * startLatLng.longitude;
double lat = t * GEOPOINTS[0].latitude + (1 - t) * startLatLng.latitude;
marker.setPosition(new LatLng(lat, lng));
if (t < 1.0) {
// Post again 16ms later.
handler.postDelayed(this, 16);
}
}
});
// We return false to indicate that we have not consumed the event and that we wish
// for the default behavior to occur (which is for the camera to move such that the
// marker is centered and for the marker's info window to open, if it has one).
return false;
}
@Override
public void onInfoWindowClick(Marker marker) {
Toast.makeText(getBaseContext(), "Click Info Window", Toast.LENGTH_SHORT).show();
}
@Override
public void onMarkerDragStart(Marker marker) {
mTopText.setText("onMarkerDragStart");
}
@Override
public void onMarkerDragEnd(Marker marker) {
mTopText.setText("onMarkerDragEnd");
}
@Override
public void onMarkerDrag(Marker marker) {
mTopText.setText("onMarkerDrag. Current Position: " + marker.getPosition());
}
class loadingTask extends AsyncTask<Void, Void,Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
}
@Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
setUpMapIfNeeded();
}
@Override
protected Void doInBackground(Void... params) {
helper = DBHelper.getInstance(con);
mArticles = helper.getArticlesList();
System.out.println(mArticles.toString());
return null;
}
}
}
但我的日志显示以下错误。
java.lang.RuntimeException: Unable to resume activity
{com.example.test/com.example.test.Map}: java.lang.NullPointerException
at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2698)
at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2726)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2212)
at android.app.ActivityThread.access$600(ActivityThread.java:139)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1205)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4899)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:791)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:558)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.example.test.Map.addMarkersToMap(Map.java:233)
at com.example.test.Map.setUpMap(Map.java:197)
at com.example.test.Map.setUpMapIfNeeded(Map.java:187)
at com.example.test.Map.onResume(Map.java:177)
at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1184)
at android.app.Activity.performResume(Activity.java:5082)
at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2688)
... 12 more
我有两个问题，第一个是显示多个地理位置，第二个是让每个标记跳转。任何人都可以帮助我。
更新：更改onResume（）后的新日志
java.lang.NullPointerException
at com.example.test.Map$1.onGlobalLayout(Map.java:217)
at android.view.ViewTreeObserver.dispatchOnGlobalLayout(ViewTreeObserver.java:646)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1726)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1000)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4214)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:725)
at android.view.Choreographer.doCallbacks(Choreographer.java:555)
at android.view.Choreographer.doFrame(Choreographer.java:525)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:711)
at android.os.Handler.handleCallback(Handler.java:615)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4899)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:791)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:558)
at dalvik.system.NativeStart.main(Native Method)
第217行
LatLngBounds bounds = new LatLngBounds.Builder().include(GEOPOINTS[0]).build();
答案 0 :(得分：2)
当您在NullPointerException
mArticles时，setUpMapIfNeeded(); null ，您将获得onResume()
所以 更改
@Override
protected void onResume() {
super.onResume();
setUpMapIfNeeded();
}
以
@Override
protected void onResume() {
super.onResume();
new loadingTask().execute();
}
修改：
GEOPOINTS[0] null位于第217行
LatLngBounds bounds = new LatLngBounds.Builder().include(GEOPOINTS[0]).build();
原因
你在private void addMarkersToMap()内遇到问题，你没有初始化GEOPOINTS，所以在for循环之前初始化GEOPOINT ，为此用途：GEOPOINTS=new LatLng[mArticles.size()];
所以看起来应该是这样的：
GEOPOINTS=new LatLng[mArticles.size()];
for (int i=0;i<mArticles.size();i++){
String latt=mArticles.get(i).latitude.trim().replace(",","");
String lonn=mArticles.get(i).longitude.trim();
//set latitude and longitude
GEOPOINTS[i] = new LatLng(Double.valueOf(latt), Double.valueOf(lonn));