如何返回的Andr​​oid LocationListener的数据 [英] How to return data in Android LocationListener

问题描述

我想建立一个应用程序中，用户可以使该标签与手机的当前位置照片。所以制作照片后，用户可以通过触摸保存按钮，保存图片。如果按钮被触摸的当前位置会用我自己的LocationListener的类来确定。监听级显示Progressdialog并驳回，一个位置后发现。但现在我想知道，我可以返回的位置回调用活动，因为位置监听器方法是回调方法。是否有一个最佳实践的解决方案，或者有任何线索？

位置监听器：

 公共类MyLocationListener实现LocationListener的{私人ProgressDialog progressDialog;
私人语境mContext;
私人的LocationManager的LocationManager;公共MyLocationListener（上下文的背景下，ProgressDialog对话）{
    mContext =背景;
    progressDialog =对话框;
}公共无效startTracking（）{
    的LocationManager =（的LocationManager）mContext.getSystemService（Context.LOCATION_SERVICE）;
    标准标准=新标准（）;
    criteria.setAccuracy（Criteria.ACCURACY_FINE）;
    criteria.setPowerRequirement（Criteria.NO_REQUIREMENT）;
    字符串提供商= locationManager.getBestProvider（标准，真正的）;
    locationManager.requestLocationUpdates（提供商，10，10，这一点）;
    progressDialog.show（）;
}私人无效finishTracking（地点）{
    如果（位置！= NULL）{
        locationManager.removeUpdates（本）;
        progressDialog.hide（）;
        Log.i（跟踪，location.toString（））;
    }
}@覆盖
公共无效onLocationChanged（地点）{
    finishTracking（位置）;
}@覆盖
公共无效onProviderDisabled（字符串提供商）{}@覆盖
公共无效onProviderEnabled（字符串提供商）{}@覆盖
公共无效onStatusChanged（字符串提供商，INT地位，捆绑演员）{}}
 

调用code：

  ProgressDialog对话框=新ProgressDialog（本）;
dialog.setTitle（确定位置......）;
新MyLocationListener（这一点，对话）.startTracking（）;
 

解决方案

为什么不从活动通过自己的回调MyLocationListener和finishTracking调用它的方法是什么？

它是一种常用的委托模式。这样的事情：

 类MyLocationListener实现LocationListener的{
    公共接口myListener的{
        无效onLocationReceiver（位置定位）;
    }    私人myListener的侦听器;    公共MyLocationListener（上下文的背景下，ProgressDialog对话框，myListener的侦听器）{
        mContext =背景;
        progressDialog =对话框;
        this.listener =侦听器;
    }    私人无效finishTracking（地点）{
        如果（位置！= NULL）{
            locationManager.removeUpdates（本）;
            progressDialog.hide（）;
            Log.i（跟踪，location.toString（））;
            listener.onLocationReceiver（位置）;
        }
    }
}
 

和调用：

 新MyLocationListener（这一点，对话框，新MyLocationListener.MyListener（）{
    公共无效onLocationReceived（地点）{
        text.setText（location.toString（））;
    }
}）startTracking（）。
 

i want to build an app in which users can make foto which is tagged with the current location of the phone. So after making a foto, the user can save the picture by touching on the "save" button. If the button is touched the current location will be determined with my own LocationListener class. The Listener-class shows a Progressdialog and dismiss it, after a location is found. But now i want to know which i can return the location back to the calling Activity, because the Location listener methods are callback methods. Is there a "best-practice" solution for that, or have anybody a clue?

Location Listener:

public class MyLocationListener implements LocationListener {

private ProgressDialog progressDialog;
private Context mContext;
private LocationManager locationManager;

public MyLocationListener(Context context, ProgressDialog dialog) {
    mContext = context;
    progressDialog = dialog;
}

public void startTracking() {
    locationManager = (LocationManager) mContext.getSystemService(Context.LOCATION_SERVICE);
    Criteria criteria = new Criteria();
    criteria.setAccuracy(Criteria.ACCURACY_FINE);
    criteria.setPowerRequirement(Criteria.NO_REQUIREMENT);
    String provider = locationManager.getBestProvider(criteria, true);
    locationManager.requestLocationUpdates(provider, 10, 10, this);
    progressDialog.show();
}

private void finishTracking(Location location) {
    if(location != null) {
        locationManager.removeUpdates(this);
        progressDialog.hide();
        Log.i("TRACKING",location.toString());
    }
}

@Override
public void onLocationChanged(Location location) {
    finishTracking(location);
}

@Override
public void onProviderDisabled(String provider) { }

@Override
public void onProviderEnabled(String provider) { }

@Override
public void onStatusChanged(String provider, int status, Bundle extras) { }

}

Calling code:

ProgressDialog dialog = new ProgressDialog(this);
dialog.setTitle("Determine position...");
new MyLocationListener(this, dialog).startTracking();

解决方案

Why not pass your own callback from activity to MyLocationListener and call its method from finishTracking?

Its a commonly used delegation pattern. Something like that:

class MyLocationListener implements LocationListener {
    public interface MyListener {
        void onLocationReceiver( Location location );
    }

    private MyListener listener;

    public MyLocationListener(Context context, ProgressDialog dialog, MyListener listener) {
        mContext = context;
        progressDialog = dialog;
        this.listener = listener;
    }

    private void finishTracking(Location location) {
        if(location != null) {
            locationManager.removeUpdates(this);
            progressDialog.hide();
            Log.i("TRACKING",location.toString());
            listener.onLocationReceiver(location);
        }
    }
}

and call:

new MyLocationListener(this, dialog, new MyLocationListener.MyListener() {
    public void onLocationReceived( Location location ) {
        text.setText(location.toString());
    }
}).startTracking();

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