关于gps Location为空值的有关问题

关于gps Location为空值的问题

Java code

        tv1=(TextView)findViewById(R.id.textView1);        tv2=(TextView)findViewById(R.id.textView2);        tv3=(TextView)findViewById(R.id.textView3);        locMan = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);        getLocationPrivider();        if(mLocation!=null){//            gp1=getGeoByLocation(mLocation);//            if(listmap.size()!=0){//                for(int i=0;i<listmap.size();i++){//                    String coordinate=map.get("coordinate");                    double gp2_lar=170.1;                    double gp2_long=170.2;                    double gp1_lar=170.11;                    double gp1_long=170.2;//                    Location loc=new Location(null);                    mLocation.setLatitude(gp2_lar);                    mLocation.setLongitude(gp2_long);                    gp2=getGeoByLocation(mLocation);                    mLocation.setLatitude(gp1_lar);                    mLocation.setLongitude(gp1_long);                    gp1=getGeoByLocation(mLocation);                    double d=getdistance(gp1,gp2);                    if(d<=100.00){                        tv1.setText(gp1_lar+"."+gp1_long);                        tv2.setText(gp2_lar+"."+gp2_long);                        tv3.setText("相隔"+d+"米");                    }else{                        tv1.setText(gp1_lar+"."+gp1_long);                        tv2.setText(gp2_lar+"."+gp2_long);                        tv3.setText("相隔"+d+"米");                    }//                }//            }        }else{            tv1.setText("mLocation为空");            tv2.setText("mLocation为空");            tv3.setText("mLocation为空");        }    /**     * 取得GeoPoint的方法     * @param location     * @return gp     */    private GeoPoint getGeoByLocation(Location location){        GeoPoint gp=null;        try{            if(location!=null){                double geoLatitude=location.getLatitude()*1E6;                double geoLongitude=location.getLongitude()*1E6;                gp=new GeoPoint((int)geoLatitude,(int)geoLongitude);            }        }catch(Exception e){            e.printStackTrace();        }        return gp;    }    /**     * 取得LocationProvider     */    public void getLocationPrivider(){        Criteria mc=new Criteria();        mc.setAccuracy(Criteria.ACCURACY_FINE);        mc.setAltitudeRequired(false);        mc.setBearingRequired(false);        mc.setCostAllowed(true);        mc.setPowerRequirement(Criteria.POWER_LOW);        mLPrivider=locMan.getBestProvider(mc,true);        mLocation=locMan.getLastKnownLocation(mLPrivider);    }/**     * 获取两点之间距离的方法,得出的距离是m     */    public double getdistance(GeoPoint gp1,GeoPoint gp2){        double Lat1r=ConvertDegreeToRadians(gp1.getLatitudeE6()/1E6);        double Lat2r=ConvertDegreeToRadians(gp2.getLatitudeE6()/1E6);        double Long1r=ConvertDegreeToRadians(gp1.getLongitudeE6()/1E6);        double Long2r=ConvertDegreeToRadians(gp2.getLongitudeE6()/1E6);        //地球半径(km)        double R=6371;        //计算得出是m        double d=Math.acos(Math.sin(Lat1r)*Math.sin(Lat2r)+Math.cos(Lat1r)*Math.cos(Lat2r)*Math.cos(Long2r-Long1r))*R;        return d;    }    /**     * ConvertDegreeToRadians     */    private double ConvertDegreeToRadians(double degrees){        return (Math.PI/180)*degrees;    }