如何获得位置时，它改变 [英] How to get location when it changes

问题描述

我想知道，有一种方式来获得的位置，如果只有它的变化？我知道Android提供此 http://developer.android.com/training/位置/接收位置updates.html 获得位置更新，因为它规定：

I would like to know there is a way to get location if only it changes? I know android provides this http://developer.android.com/training/location/receive-location-updates.html to get location updates and as it states:

如果你的应用程序做导航或跟踪，你可能想获取用户的位置，定期进行。虽然可以用LocationClient.getLastLocation（）做到这一点，更直接的办法是要求从位置服务定期更新。在对此，定位服务自动更新提供当前最佳的位置您的应用程序的基础上，当前可用的位置，供应商，如WiFi和GPS。

"If your app does navigation or tracking, you probably want to get the user's location at regular intervals. While you can do this with LocationClient.getLastLocation(), a more direct approach is to request periodic updates from Location Services. In response, Location Services automatically updates your app with the best available location, based on the currently-available location providers such as WiFi and GPS."

怎么做，而不使用固定时间间隔？其主要目标是最大限度地降低功耗。例如，如果我在一个房间里坐着，不会有位置的变化。如果我开始移动，它应该报告的位置变化。

How to do it without using regular intervals? The main goal is to minimize power consumption. For example, if i am in a room and sitting, there will be no location change. If i start moving, it should report the location changes.

我确实需要得到，如果只更新位置，所以不会经常。

I do need to get locations if only update, so not constantly.

的方法，应在后台持续运行，并提供以功率有效的方式全部位置更新。

The method should run on the background continuously and provide the all location updates in a power efficient way.

我在这里找到Android的融合定位API https://developer.android.com /google/play-services/location.html

I found android fused location API here https://developer.android.com/google/play-services/location.html

有关使用该如何？

我可以实现它不使用定期？

Can i implement it without using regular intervals?

推荐答案

此方法需要GooglePlayService，它并不需要多大的力量，也许你可以试试。

This method requires GooglePlayService, and it doesn't need much power, maybe you can try it.

private LocationClient locationClient;
private static final int LOCATION_UPDATES_INTERVAL = 10000;
private static final int LOCATION_NUM_UPDATES = 5;

public void startLocationUpdate() {
    if (!(locationClient.isConnected() || locationClient.isConnecting())) {
        locationClient.connect(); // Somehow it becomes connected here
        return;
    }
    // Request for location updates
    LocationRequest request = LocationRequest.create();
    request.setInterval(LOCATION_UPDATES_INTERVAL);
    request.setPriority(LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY);
    request.setNumUpdates(LOCATION_NUM_UPDATES);
    locationClient.requestLocationUpdates(request, this);
}

而在活动中，您应该实现以下回调

And in the Activity you should implement the following callback

private Location mLastLocation;
    @Override
public void onLocationChanged(Location location) {
    if (location == null) {
        Log.v(TAG, "onLocationChanged: location == null");
        return;
    }

    if (mLastLocation != null &&
            mLastLocation.getLatitude() == location.getLatitude() &&
            mLastLocation.getLongitude() == location.getLongitude()) {
        return;
    }
    LogUtil.i(TAG, "LocationChanged == @" +
            location.getLatitude() + "," + location.getLongitude());
    mLastLocation = location;
}

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