java - LocationServices.FusedLocationApi.requestLocationUpdates 未设置位置

Question

我正在尝试使用 GoogleAPIClient 获取实时位置更新。虽然 GoogleAPIClient 已连接但位置对象为空，并且它提示 location.getProvider() 为空。有人可以帮忙吗？

这是我的代码:

public void onConnected(Bundle connectionHint) {
    Log.i(TAG, "Connected to GoogleApiClient " + myGoogleApiClient.isConnected());

    myCurrentLocation = LocationServices.FusedLocationApi.getLastLocation(myGoogleApiClient);
    // Debug - At this point myCurrentLocation  is NULL
        if (myCurrentLocation == null) {
            Log.i(TAG, "myCurrentLocation is : " + myCurrentLocation);
            // Debug - myCurrentLocation  is STILL NULL
            LocationServices.FusedLocationApi.requestLocationUpdates(
                    myGoogleApiClient, myLocationRequest, this);
            // Debug - app crashes with stack trace below at this point
            Log.i(TAG, "Doesnt't reach here : " + myCurrentLocation);
        }

        myLastUpdateTime = DateFormat.getTimeInstance().format(new Date());
        updateUILayout();

}

    protected synchronized void buildGoogleApiClient() {
    Log.i(TAG, "Building GoogleApiClient");
    myGoogleApiClient = new GoogleApiClient.Builder(this)
            .addConnectionCallbacks(this)
            .addOnConnectionFailedListener(this)
            .addApi(LocationServices.API)
            .build();
    Log.i(TAG, "myGoogleApiClient is :" + myGoogleApiClient.isConnected());
    createLocationRequest();
}

protected void createLocationRequest() {
    myLocationRequest = new LocationRequest();
    myLocationRequest.setInterval(10000);
    myLocationRequest.setFastestInterval(5000);
    myLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
}

调试后我发现的主要问题是:

 LocationServices.FusedLocationApi.requestLocationUpdates(
                    myGoogleApiClient, myLocationRequest, this);

这不是设置 myCurrentLocation。它始终为 NULL。在 ADB logcat 中说:

java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.location.Location.getProvider()' on a null object reference
        at com.adrenalin.myfirstapp.MyActivity.onConnected(MyActivity.java:130)
        at com.google.android.gms.internal.jm.f(Unknown Source)
        at com.google.android.gms.common.api.c.gJ(Unknown Source)
        at com.google.android.gms.common.api.c.d(Unknown Source)
        at com.google.android.gms.common.api.c$2.onConnected(Unknown Source)
        at com.google.android.gms.internal.jm.f(Unknown Source)
        at com.google.android.gms.internal.jm.dU(Unknown Source)
        at com.google.android.gms.internal.jl$h.b(Unknown Source)

Answer 1

当你实现

LocationServices.FusedLocationApi.requestLocationUpdates(
                    myGoogleApiClient, myLocationRequest, this);

您需要覆盖 onLocationChanged 的回调，以便它知道在更新时如何处理位置。

试试这个:

@Override
public void onLocationChanged(Location location) {
    myCurrentLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
}