LocationActivity.java
/* LocationActivity.java
* @author octobershiner
* 2011 7 24
* SE.HIT
* 利用Criteria選擇最優的位置服務，演示定位用戶的位置並且監聽位置變化的代碼
* */
package uni.location;
import android.app.Activity;
import android.content.Context;
import android.location.Criteria;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.Vibrator;
import android.util.Log;
import android.widget.TextView;
public class LocationActivity extends Activity {
/** Called when the activity is first created. */
//創建lcoationManager對象
private LocationManager manager;
private static final String TAG = "LOCATION DEMO";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//獲取系統的服務，
manager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
//創建一個criteria對象
Criteria criteria = new Criteria();
criteria.setAccuracy(Criteria.ACCURACY_COARSE);
//設置不需要獲取海拔方向數據
criteria.setAltitudeRequired(false);
criteria.setBearingRequired(false);
//設置允許產生資費
criteria.setCostAllowed(true);
//要求低耗電
criteria.setPowerRequirement(Criteria.POWER_LOW);
String provider = manager.getBestProvider(criteria, false);
Log.i(TAG, "we choose "+ provider);
Location location = manager.getLastKnownLocation(provider);
//第一次獲得設備的位置
updateLocation(location);
//重要函數，監聽數據測試
manager.requestLocationUpdates(provider, 6000, 10,
locationListener);
}
//創建一個事件監聽器
private final LocationListener locationListener = new LocationListener() {
public void onLocationChanged(Location location) {
updateLocation(location);
}
public void onProviderDisabled(String provider){
updateLocation(null);
Log.i(TAG, "Provider now is disabled..");
}
public void onProviderEnabled(String provider){
Log.i(TAG, "Provider now is enabled..");
}
public void onStatusChanged(String provider, int status,Bundle extras){ }
};
//獲取用戶位置的函數，利用Log顯示
private void updateLocation(Location location) {
String latLng;
if (location != null) {
double lat = location.getLatitude();
double lng = location.getLongitude();
latLng = "Latitude:" + lat + " Longitude:" + lng;
} else {
latLng = "Can't access your location";
}
Log.i(TAG, "The location has changed..");
Log.i(TAG, "Your Location:" +latLng);
}
}
同時修改manifest.xml文件
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="uni.location"
android:versionCode="1"
android:versionName="1.0">
<uses-sdk android:minSdkVersion="8" />
<application android:icon="@drawable/icon" android:label="@string/app_name">
<activity android:name=".LocationActivity"
android:label="@string/app_name">
<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" />
</manifest>
演示結果：
可任看到 我們隻要求低的精確度並且最低電量，從最後一行可以看到我的虛擬機網絡服務並沒有打開，但是選擇最佳provider的時候，參數選擇瞭false 所以同樣可以選擇。
摘自 Octobershiner的專欄
