Question

我正在尝试制作一个Android应用程序，它以一定的间隔获取位置数据，例如： - 5秒，1分钟等。这是我的代码： -

            public void onLocationChanged(Location loc) {
            // TODO Auto-generated method stub
            if(loc!=null)
            {   
              //Required Interval
              tInterval =(minInterval*60*1000) + (secInterval)*1000 - 1000;

              //The app also supports interval mode
              RadioButton sel = (RadioButton) findViewById(mode.getCheckedRadioButtonId()); 

              //Code for Manual Functionality
              if(sel.getText().equals(MANUAL_RADIO))
              {
                      Time t = new Time();
                      t.setToNow();
                      db.addLocationAtTime(loc, t);
                      Toast.makeText(getApplicationContext(), "Location Added to Database",Toast.LENGTH_SHORT).show();        
                      locate.removeUpdates(this);

                      b.setText(MANUAL_BUTTON);
                      d.setEnabled(true);
              }

              //Code for Interval functionality
              else if(sel.getText().equals(INTERVAL_RADIO))
              {
                              //count is object of Countdown class which is a Thread object
                              if(count == null)
                              {
                                      //t is a Time object
                                      t.setToNow();
                                      //SQLiteDatabase object for logging Location with Time
                                      db.addLocationAtTime(loc, t);
                                      Toast.makeText(getApplicationContext(), "Location Added to Database",Toast.LENGTH_SHORT).show();
                                      count =  new CountDown( tInterval);
                                      count.start();
                              }

                              else if(count.getState().toString().equals("TERMINATED"))
                              {
                                      t.setToNow();
                                      db.addLocationAtTime(loc, t);
                                      Toast.makeText(getApplicationContext(), "Location Added to Database",Toast.LENGTH_SHORT).show();
                                      count =  new CountDown(tInterval);
                                      count.start();                                  
                              }

                  }
              }
            }

以下是Countdown类的代码： - 此类用于将间隔添加到应用程序

public class CountDown extends Thread 
{
    long time;
    public CountDown(long duration)
    {
            time = duration;
    }

    public void run()
    {
                    long t1 = System.currentTimeMillis();
                    long t2 = 0;
                    do
                    {
                      t2 = System.currentTimeMillis();      
                    }while(t2 - t1 < time);            
    }
}

问题是使用上面的代码我没有得到准确的间隔。我总是得到额外的1秒（因为我在公式中减去了1000），但这1秒并不总是发生。那么有人可以告诉我我做错了吗？

Answer 1

查看LocationManager.requestLocationUpdates，只需在参数..

中传递您的时间间隔

LocationManager mLocationManager = (LocationManager).getSystemService(mActivity.LOCATION_SERVICE);
mLocationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 5000, 0, new GeoUpdateHandler());

Answer 2

我认为您需要使用默认功能，无需使用Timer

<强> NETWORK_PROVIDER

locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 3000, 0, networkLocationListener);

<强> GPS_PROVIDER

locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 3000, 0, gpsLocationListener);

在这里，

minTime(2nd field)      =>   minimum time interval between location updates, in milliseconds
minDistance(3rd field)  =>   minimum distance between location updates, in meters

Documentation

Answer 3

我认为requestLocationUpdates（...）方法的minTime参数根本不做任何事情。它似乎不会阻止基于距离的更新以较短的间隔进行，并且它肯定不会导致更新以指定的间隔出现，正如许多人似乎认为的那样。我在Android 2.3.6到4.0.4的设备上尝试过它。

以特定间隔在Android设备上获取位置数据

3 个答案: