位置管理器在Android应用程序

Question

我创建简单的android应用程序显示设备的位置，但是当我在模拟器中运行时，它显示运行应用程序的错误。

package my.loc; 

import android.app.Activity; 
import android.content.Context; 
import android.location.Location; 
import android.location.LocationManager; 
import android.os.Bundle; 
import android.widget.TextView; 

public class LocActivity extends Activity { 
    /** Called when the activity is first created. */ 
    TextView textView; 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     textView = (TextView) findViewById(R.id.text_view); 
     LocationManager manager = 
      (LocationManager) getSystemService(Context.LOCATION_SERVICE); 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main); 
     Location loc = 
      manager.getLastKnownLocation(LocationManager.GPS_PROVIDER); 
      textView.setText("latitude: " + loc.getLatitude() 
      + "\nlongitude: " + loc.getLongitude()); 
    } } 

Activity.xml文件是诸如

<?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" > 

    <TextView 
     android:id="@+id/text_view" 
     /> 

和清单是如

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

    <uses-sdk android:minSdkVersion="8" /> 
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" /> 
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/> 

    <application 
     android:icon="@drawable/ic_launcher" 
     android:label="@string/app_name" > 
     <activity 
      android:label="@string/app_name" 
      android:name=".LocActivity" > 
      <intent-filter > 
       <action android:name="android.intent.action.MAIN" /> 

       <category android:name="android.intent.category.LAUNCHER" /> 
      </intent-filter> 
     </activity> 
    </application> 

错误是：

应用程序loc已经意外停止。

Answer 1

您必须让您的课程实施LocationListener并致电manager.requestLocationUpdates()以获取位置信息。请参阅http://developer.android.com/training/location/receive-location-updates.html