【发布时间】：2012-08-20 05:48:53
【问题描述】：
所以，我一直在努力让它运行一段时间。问题是我在 main.xml 中正确放置了来自 Google 的地图密钥，但我似乎无法获得提供者信息，因为地图根本不显示。我已经运行了几次，但我们都在同一个地方失败了。我尝试调试并注意到返回了一个提供程序字符串，但是之后返回了一个空值。
代码在
处失败@Override
protected void onResume() {
super.onResume();
locationManager
.requestLocationUpdates(getBestProvider(), 1000, 1, this);
}
带有以下错误消息。
08-20 05:14:43.573: E/AndroidRuntime(239): Uncaught handler: thread main exiting due to uncaught exception
08-20 05:14:43.583: E/AndroidRuntime(239): java.lang.RuntimeException: Unable to resume activity {com.shawnbe.mallfinder/com.shawnbe.mallfinder.MallFinderActivity}: java.lang.NullPointerException
08-20 05:14:43.583: E/AndroidRuntime(239): at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2950)
08-20 05:14:43.583: E/AndroidRuntime(239): at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2965)
08-20 05:14:43.583: E/AndroidRuntime(239): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2516)
08-20 05:14:43.583: E/AndroidRuntime(239): at android.app.ActivityThread.access$2200(ActivityThread.java:119)
08-20 05:14:43.583: E/AndroidRuntime(239): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1863)
08-20 05:14:43.583: E/AndroidRuntime(239): at android.os.Handler.dispatchMessage(Handler.java:99)
08-20 05:14:43.583: E/AndroidRuntime(239): at android.os.Looper.loop(Looper.java:123)
08-20 05:14:43.583: E/AndroidRuntime(239): at android.app.ActivityThread.main(ActivityThread.java:4363)
08-20 05:14:43.583: E/AndroidRuntime(239): at java.lang.reflect.Method.invokeNative(Native Method)
08-20 05:14:43.583: E/AndroidRuntime(239): at java.lang.reflect.Method.invoke(Method.java:521)
08-20 05:14:43.583: E/AndroidRuntime(239): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
08-20 05:14:43.583: E/AndroidRuntime(239): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
08-20 05:14:43.583: E/AndroidRuntime(239): at dalvik.system.NativeStart.main(Native Method)
08-20 05:14:43.583: E/AndroidRuntime(239): Caused by: java.lang.NullPointerException
08-20 05:14:43.583: E/AndroidRuntime(239): at com.shawnbe.mallfinder.MallFinderActivity.onResume(MallFinderActivity.java:61)
08-20 05:14:43.583: E/AndroidRuntime(239): at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1149)
08-20 05:14:43.583: E/AndroidRuntime(239): at android.app.Activity.performResume(Activity.java:3763)
08-20 05:14:43.583: E/AndroidRuntime(239): at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2937)
08-20 05:14:43.583: E/AndroidRuntime(239): ... 12 more
有时，代码似乎启动了网格但没有地图。在其他运行中，它只是失败了。
以下是我的活动代码。
package com.shawnbe.mallfinder;
import java.util.List;
import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapController;
import com.google.android.maps.MapView;
import com.google.android.maps.Overlay;
import com.google.android.maps.OverlayItem;
import android.content.Context;
import android.graphics.drawable.Drawable;
import android.location.Criteria;
import android.location.Location;
import android.os.Bundle;
import android.widget.TextView;
import android.widget.Toast;
public class MallFinderActivity extends MapActivity implements
android.location.LocationListener {
/** Called when the activity is first created. */
private MapController mapController;
private MapView mapView;
private android.location.LocationManager locationManager;
private GeoPoint currentPoint;
private Location currentLocation = null;
private TextView latituteField;
private TextView longitudeField;
private String bestProvider;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
MapView mapView = (MapView) findViewById(R.id.mapView);
mapView.setBuiltInZoomControls(true);
Location location;
//getBestProvider();
if(bestProvider !=null)
location = locationManager.getLastKnownLocation(bestProvider);
List<Overlay> mapOverlays = mapView.getOverlays();
Drawable drawable = this.getResources().getDrawable(
R.drawable.androidmarker);
MapItemizedOverlay itemizedoverlay = new MapItemizedOverlay(drawable,
this);
LocalGeoPoints loc = new LocalGeoPoints();
for (OverlayItem a : loc.overlayitems) {
itemizedoverlay.addOverlay(a);
}
mapOverlays.add(itemizedoverlay);
}
@Override
protected void onResume() {
super.onResume();
locationManager
.requestLocationUpdates(getBestProvider(), 1000, 1, this);
}
public void getLastLocation() {
String provider = getBestProvider();
currentLocation = locationManager.getLastKnownLocation(provider);
if (currentLocation != null) {
setCurrentLocation(currentLocation);
} else {
Toast.makeText(this, "Location not yet acquired", Toast.LENGTH_LONG)
.show();
}
}
public void animateToCurrentLocation() {
if (currentPoint != null) {
mapController.animateTo(currentPoint);
}
}
public String getBestProvider() {
locationManager = (android.location.LocationManager) getSystemService(Context.LOCATION_SERVICE);
Criteria criteria = new Criteria();
criteria.setPowerRequirement(Criteria.NO_REQUIREMENT);
criteria.setAccuracy(Criteria.NO_REQUIREMENT);
bestProvider = locationManager.getBestProvider(criteria, false);
return bestProvider;
}
public void setCurrentLocation(Location location) {
int currLatitude = (int) (location.getLatitude() * 1E6);
int currLongitude = (int) (location.getLongitude() * 1E6);
currentPoint = new GeoPoint(currLatitude, currLongitude);
currentLocation = new Location("");
currentLocation.setLatitude(currentPoint.getLatitudeE6() / 1e6);
currentLocation.setLongitude(currentPoint.getLongitudeE6() / 1e6);
}
@Override
protected boolean isRouteDisplayed() {
return false;
}
/* Remove the locationlistener updates when Activity is paused */
@Override
protected void onPause() {
super.onPause();
locationManager.removeUpdates(this);
}
@Override
public void onLocationChanged(Location location) {
int lat = (int) (location.getLatitude());
int lng = (int) (location.getLongitude());
latituteField.setText(String.valueOf(lat));
longitudeField.setText(String.valueOf(lng));
}
@Override
public void onProviderEnabled(String provider) {
Toast.makeText(this, "Enabled new provider " + provider,
Toast.LENGTH_SHORT).show();
}
@Override
public void onProviderDisabled(String provider) {
Toast.makeText(this, "Disabled provider " + provider,
Toast.LENGTH_SHORT).show();
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
}
}
下面是我从谷歌地图注册站点获得的密钥的 main.xml ccomplete。
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<FrameLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<com.google.android.maps.MapView
android:id="@+id/mapView"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:clickable="true"
android:apiKey="0steid872FeGgae0eO2Dhdyei37sFPHG65t7N6XA"/>
</FrameLayout>
</LinearLayout>
【问题讨论】：
-
See this link 了解更多信息。
-
我已经正确设置了密钥。
-
我认为这个错误只会因为错误的密钥而发生。
-
但我拥有使用我签署应用程序时的 MD5 指纹生成的正确密钥。除了在运行之前将其添加到 main.xml 文件之外，我还需要做什么？
-
请删除您立即发布的 Google Maps API 密钥。人们很容易滥用它。
标签： java android google-maps