android - 如何在 Android 的 OnCompleteListener 中返回值？

Question

我正在尝试获取智能手机的 GPS，如下面的代码:

在 Activity.java ，我使用以下代码获取 GPS。

private GPSClass gps;
gps.getGPSLocation();

在 GPSClass.java

public void getGPSLocation(){
        FusedLocationProviderClient mLocationClient = LocationServices.getFusedLocationProviderClient(mContext);
        mLocationClient.getLastLocation().addOnCompleteListener(mContext, new OnCompleteListener<Location>() {
            @Override
            public void onComplete(@NonNull Task<Location> task) {
                if(task.isSuccessful()){
                    mLocation = task.getResult();
                    Log.i("getLocation---LOCATION", mLocation.getLatitude() + "/"
                            + mLocation.getLongitude());

                }
            }
        });
    }

但是如何返回中的值GPSClass.java ？

我已经尝试更换

public void onComplete

代替

public Location onComplete

但是显示错误

'onComplete(Task<Location>)' in 'Anonymous class derived from com.google.android.gms.tasks.OnCompleteListener' clashes with 'onComplete(Task<TResult>)' in 'com.google.android.gms.tasks.OnCompleteListener'; attempting to use incompatible return type

我错过了什么吗？如何返回 OnCompleteListener 中的值？提前致谢。

Answer 1

您可以使用回调，例如

public void getGPSLocation(GPSCallback callback){
        FusedLocationProviderClient mLocationClient = LocationServices.getFusedLocationProviderClient(mContext);
        mLocationClient.getLastLocation().addOnCompleteListener(mContext, new OnCompleteListener<Location>() {
            @Override
            public void onComplete(@NonNull Task<Location> task) {
                if(task.isSuccessful()){
                    mLocation = task.getResult();
                    Log.i("getLocation---LOCATION", mLocation.getLatitude() + "/"
                            + mLocation.getLongitude());
                    callback.onLocation(mLocation);
                }
            }
        });
    }

创建一个名为 GPSCallback 的接口(interface)，例如

interface GPSCallback{
void onLocation(Location location);
}

并通过回调调用方法

gps.getGPSLocation(new GPSCallback() {
    void onLocation(Location location) {
        // do what you need to do with the location
    }
});