因为定位的不肯定性,每次位置的更新不见得是最精确的,因此咱们须要和上一个位置作比较,来判断是否使用此次的位置。java
下面是API的示例代码:ide
private static final int TWO_MINUTES = 1000 * 60 * 2; /** 判断哪种位置读取方式比当前的位置修复更加的准确 * @param location 新位置 * @param currentBestLocation 当前的位置,此位置须要和新位置进行比较 */ protected boolean isBetterLocation(Location location, Location currentBestLocation) { if (currentBestLocation == null) { // A new location is always better than no location return true; } //检查最新的位置是比较新仍是比较旧 long timeDelta = location.getTime() - currentBestLocation.getTime(); boolean isSignificantlyNewer = timeDelta > TWO_MINUTES; boolean isSignificantlyOlder = timeDelta < -TWO_MINUTES; boolean isNewer = timeDelta > 0; //若是当前的位置信息来源于两分钟前,使用最新位置, // 由于用户可能移动了 if (isSignificantlyNewer) { return true; //若是最新的位置也来源于两分钟前,那么此位置会更加的不许确。 } else if (isSignificantlyOlder) { return false; } //检查最新的位置信息是更加的准确仍是不许确 int accuracyDelta = (int) (location.getAccuracy() - currentBestLocation.getAccuracy()); boolean isLessAccurate = accuracyDelta > 0; boolean isMoreAccurate = accuracyDelta < 0; boolean isSignificantlyLessAccurate = accuracyDelta > 200; //检查旧的位置和新的位置是否来自同一个provider boolean isFromSameProvider = isSameProvider(location.getProvider(), currentBestLocation.getProvider()); //结合及时性和精确度,决定位置信息的质量 if (isMoreAccurate) { return true; } else if (isNewer && !isLessAccurate) { return true; } else if (isNewer && !isSignificantlyLessAccurate && isFromSameProvider) { return true; } return false; } /*** 检查两个提供者是不是同一个*/ private boolean isSameProvider(String provider1, String provider2) { if (provider1 == null) { return provider2 == null; } return provider1.equals(provider2);