Android 得到地理位置并分析出具体城市

/**
	 * 通过GPS得到城市名
	 * 
	 * @param context
	 *            一個Activity
	 * @return 城市名
	 */
	public static String getCityName(Context context) {
		LocationManager locationManager;
		String contextString = Context.LOCATION_SERVICE;
		locationManager = (LocationManager) context.getSystemService(contextString);
		Criteria criteria = new Criteria();
		criteria.setAccuracy(Criteria.ACCURACY_FINE);
		criteria.setAltitudeRequired(false);
		criteria.setBearingRequired(false);
		criteria.setCostAllowed(false);
		criteria.setPowerRequirement(Criteria.POWER_LOW);
		String cityName = null;
		// 取得效果最好的criteria
		String provider = locationManager.getBestProvider(criteria, true);
		if (provider == null) {
			return null;
		}
		// 得到坐标相关的信息
		Location location = locationManager.getLastKnownLocation(provider);
		if (location == null) {
			return null;
		}

		if (location != null) {
			double latitude = location.getLatitude();
			double longitude = location.getLongitude();
			// 更具地理环境来确定编码
			Geocoder gc = new Geocoder(context, Locale.getDefault());
			try {
				// 取得地址相关的一些信息\经度、纬度
				List<Address> addresses = gc.getFromLocation(latitude, longitude, 1);
				StringBuilder sb = new StringBuilder();
				if (addresses.size() > 0) {
					Address address = addresses.get(0);
					sb.append(address.getLocality()).append("\n");
					cityName = sb.toString();
				}
			} catch (IOException e) {
			}
		}
		return cityName;
	}