我正在制作一个使用GPS接收器的应用程序。应用程序将在1.6版开始的所有版本上运行。我有一个卫星图标,可以告诉用户当前状态:
-
如果图标为红色-gps已禁用
-
如果图标为橙色-gps已启用并尝试修复卫星
-
如果图标为绿色-gps已修复并且运行正常。
在阅读了这里之后,我发现onLocationChanged触发器的一些事件在1.6版本上发生了变化,但不是以后的版本,所以按照建议我实现了一个GPS监听器。当图标的状态变得混乱时,我有一些非常奇怪的行为。例如,我启用GPS,得到橙色。。。修好后,变绿。。几秒钟后,在第二个橘子等之后被读取。。。
这是我使用的代码。请提出改变的建议
public class TrackExecutionActivity extends Activity{
protected static final long GPS_UPDATE_TIME_INTERVAL=3000; //millis
protected static final float GPS_UPDATE_DISTANCE_INTERVAL=0; //meters
private LocationManager mlocManager;
private MyGPSListener mGpsListener;
private LocationListener mlocListener;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.trackexecution);
imgGpsState = (ImageView)findViewById(R.id.imgGpsState);
mlocManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
mlocListener = new MyLocationListener();
mGpsListener = new MyGPSListener();
}
private class MyGPSListener implements GpsStatus.Listener {
public void onGpsStatusChanged(int event) {
boolean isGPSFix = false;
switch (event) {
case GpsStatus.GPS_EVENT_SATELLITE_STATUS:
if (mLastLocation != null)
isGPSFix = (SystemClock.elapsedRealtime() - mLastLocationMillis) < GPS_UPDATE_TIME_INTERVAL * 2;
if (isGPSFix) { // A fix has been acquired.
imgGpsState.setImageDrawable(ctx.getResources().getDrawable(R.drawable.gps_on_green));
} else { // The fix has been lost.
imgGpsState.setImageDrawable(ctx.getResources().getDrawable(R.drawable.gps_on_orange));
}
break;
case GpsStatus.GPS_EVENT_FIRST_FIX:
imgGpsState.setImageDrawable(ctx.getResources().getDrawable(R.drawable.gps_on_green));
break;
case GpsStatus.GPS_EVENT_STARTED:
imgGpsState.setImageDrawable(ctx.getResources().getDrawable(R.drawable.gps_on_orange));
break;
case GpsStatus.GPS_EVENT_STOPPED:
imgGpsState.setImageDrawable(ctx.getResources().getDrawable(R.drawable.gps_on_red));
break;
}
}
}
public class MyLocationListener implements LocationListener
{
public void onLocationChanged(Location location)
{
if (location != null) {
mLastLocationMillis = SystemClock.elapsedRealtime();
// do some things here
mLastLocation = location;
}
public void onProviderDisabled(String provider)
{
imgGpsState.setImageDrawable(ctx.getResources().getDrawable(R.drawable.gps_on_red));
}
public void onProviderEnabled(String provider)
{
imgGpsState.setImageDrawable(ctx.getResources().getDrawable(R.drawable.gps_on_orange));
}
//this doesn't trigger on Android 2.x users say
public void onStatusChanged(String provider, int status, Bundle extras)
{
}
}
}
@Override
protected void onResume() {
if(mlocManager != null) {
if (mGpsListener == null)
{
mGpsListener = new MyGPSListener();
}
if (mlocListener == null)
{
mlocListener = new MyLocationListener();
}
mlocManager.addGpsStatusListener(mGpsListener);
mlocManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, GPS_UPDATE_TIME_INTERVAL, GPS_UPDATE_DISTANCE_INTERVAL, mlocListener);
}
super.onResume();
}
}