安卓 GPS 地图

Question

我想制作 GPS 应用程序，我从另一个教程中复制粘贴的代码开始。但是当我测试该应用程序时，它出现空白，并且地图没有出现！有谁可以帮忙吗？？！！

这是代码

 package com.manita.mapuse;

import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.view.KeyEvent;
import android.widget.Toast;

import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapController;
import com.google.android.maps.MapView;



 public class MapuseActivity extends MapActivity implements LocationListener {
     private MapView  mapView = null;
     private LocationManager  lm = null;
     private double lat = 0;
     private double lng = 0;
     private MapController mc = null;

     @Override
     public void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     setContentView(R.layout.main);
     mapView = (MapView) this.findViewById(R.id.mapView);
     mapView.setBuiltInZoomControls(true);

     lm = (LocationManager) this.getSystemService(LOCATION_SERVICE);
     lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 10000, 0, this);
     lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 10000, 0, this);

     mc = mapView.getController();
     mc.setZoom(12);
     }

     @Override
     protected boolean isRouteDisplayed()
     {
     return false;
     }

     @Override
     public boolean onKeyDown(int keyCode, KeyEvent event)
     {
     if (keyCode == KeyEvent.KEYCODE_S)
     {
     mapView.setSatellite(!mapView.isSatellite());
     return true;
     }
     return super.onKeyDown(keyCode, event);
     }

     @Override
     public void onLocationChanged(Location location)
     {
     lat = location.getLatitude();
     lng = location.getLongitude();
     Toast.makeText(getBaseContext(),
     "Location change to : Latitude = " + lat + " Longitude = " + lng,
     Toast.LENGTH_SHORT).show();
     GeoPoint p = new GeoPoint((int) (lat * 1E6), (int) (lng * 1E6));
     mc.animateTo(p);
     mc.setCenter(p);
     }

     @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

     }
 }

这是manifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.manita.mapuse"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk android:minSdkVersion="7" />

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" >
        <uses-library android:name="com.google.android.maps" />
        <activity
            android:label="@string/app_name"
            android:name=".MapuseActivity" >
             <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

    </application>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_GPS" />
<uses-permission android:name="android.permission.LOCATION" />
</manifest>

这是我的MainActivity.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/mainlayout"
    android:orientation="vertical"
    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:enabled="true"
 android:clickable="true"
 android:apiKey="@string/mapKey"
 />
    <LinearLayout android:id="@+id/zoom" 
        android:layout_width="wrap_content" 
        android:layout_height="wrap_content" 
        android:layout_alignParentBottom="true" 
        android:layout_centerHorizontal="true" 
        /> 

</RelativeLayout>

谢谢。

Answer 1

我假设您正在模拟器上测试代码。看看这个：http:// blogspot.fluidnewmedia.com/2009/04/displaying-google-maps-in-the-android-emulator/

Answer 2

您是否在 http://code.google.com 上注册了 Android Maps API /android/maps-api-signup.html？

为了使用该服务，必须这样做。

Answer 3

如果您的应用程序是白色的，一种可能的解决方案是为谷歌地图创建一个新的 API 密钥。我有同样的问题。创建后将其放入清单中即可开始