textview中的android gps距离在应用程序第二次运行时显示上一个距离_Android_Gps

textview中的android gps距离在应用程序第二次运行时显示上一个距离

android gps

textview中的android gps距离在应用程序第二次运行时显示上一个距离,android,gps,Android,Gps,我有一个应用程序，每100米计算一次距离。有一个按钮和一个文本视图。当我单击按钮并开始行走时，距离显示在文本视图中。当我第二次单击按钮到达目的地后，应用程序停止。但是当我第二次启动应用程序时，它会显示在文本视图中，前面的距离应该是0 以下是我的活动： public class Gps extends Activity { TextView display; Button start; boolean doubleclick = false; AnimationDrawable AppNameA

我有一个应用程序，每100米计算一次距离。有一个按钮和一个文本视图。当我单击按钮并开始行走时，距离显示在文本视图中。当我第二次单击按钮到达目的地后，应用程序停止。但是当我第二次启动应用程序时，它会显示在文本视图中，前面的距离应该是0

以下是我的活动：

public class Gps extends Activity {

TextView display;
Button start;
boolean doubleclick = false;
AnimationDrawable AppNameAnimation;
private boolean enabled;
double currentLon = 0;
double currentLat = 0;
double lastLon = 0;
double lastLat = 0;
double distance;
Animation animRotate;
TextView startStop;

LocationManager lm;

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    this.requestWindowFeature(Window.FEATURE_NO_TITLE);
    setContentView(R.layout.activity_test);
    startStop = (TextView) findViewById(R.id.textView2);
    display = (TextView) findViewById(R.id.textView1);
    start = (Button) findViewById(R.id.button1);
    animRotate = AnimationUtils.loadAnimation(this,
            R.anim.anim_rotate);

    start.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            if (!doubleclick) {
                lm = (LocationManager) getSystemService(LOCATION_SERVICE);
                enabled = lm
                        .isProviderEnabled(LocationManager.GPS_PROVIDER);
                if (!enabled) {
                    Intent inte = new Intent(
                            Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                    startActivity(inte);
                } else {
                    lm.requestLocationUpdates(lm.GPS_PROVIDER, 0, 0,
                            Loclist);
                    Location loc = lm.getLastKnownLocation(lm.GPS_PROVIDER);

                    if (loc == null) {
                        display.setText("No GPS location found");
                    } else {
                        // set Current latitude and longitude
                        currentLon = loc.getLongitude();
                        currentLat = loc.getLatitude();
                        Log.e("Location", "currentLat:" + currentLat);

                    }
                    // Set the last latitude and longitude
                    startStop.setText("Stop");
                    lastLat = currentLat;
                    lastLon = currentLon;
                    doubleclick = true;
                }
            } else {
                lm.removeUpdates(Loclist);
                startStop.setText("Start");
                v.clearAnimation();
                doubleclick = false;
                Intent in = new Intent(Gps.this, NextActivity.class);
                //in.putExtra("distance", display.toString());
                startActivity(in);
                display.setText("0.0km");
            }

        }
    });
}

LocationListener Loclist = new LocationListener() {

    @Override
    public void onLocationChanged(Location location) {
        // TODO Auto-generated method stub

        // start location manager
        LocationManager lm = (LocationManager) getSystemService(LOCATION_SERVICE);

        // Get last location
        Location loc = lm.getLastKnownLocation(lm.GPS_PROVIDER);

        // Request new location
        lm.requestLocationUpdates(lm.GPS_PROVIDER, 0, 0, Loclist);

        // Get new location
        Location loc2 = lm.getLastKnownLocation(lm.GPS_PROVIDER);

        // get the current lat and long
        currentLat = loc.getLatitude();
        currentLon = loc.getLongitude();


        Location locationA = new Location("point A");
        locationA.setLatitude(lastLat);
        locationA.setLongitude(lastLon);

        Location locationB = new Location("point B");
        locationB.setLatitude(currentLat);
        locationB.setLongitude(currentLon);
        if (lastLat != 0 || lastLon != 0) {
            double distanceMeters = locationA.distanceTo(locationB);

            double distanceKm = distanceMeters / 1000f;

            display.setText(String.format("%.2f Km", distanceKm));
            Constant.distance = (String.format("%.2f Km", distanceKm));
            start.startAnimation(animRotate);
        }

    }

    @Override
    public void onProviderDisabled(String provider) {
        // TODO Auto-generated method stub

    }

    @Override
    public void onProviderEnabled(String provider) {
        // TODO Auto-generated method stub

    }

    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) {
        // TODO Auto-generated method stub

    }

};

@Override
protected void onResume() {
    // TODO Auto-generated method stub
    super.onResume();
    display.setText("0.0km");

}



}

请帮助我。

在开始之前添加这些行。setOnClickListenernew View.OnClickListener{}

编辑：

在locationChanged listener中更改此行。如下所示：

 // get the current lat and long
    currentLat = loc2.getLatitude();
    currentLon = loc2.getLongitude();

public class Gps extends Activity {    
TextView display;
Button start;
boolean doubleclick = false;
AnimationDrawable AppNameAnimation;
private boolean enabled;
double currentLon = 0;
double currentLat = 0;
double lastLon = 0;
double lastLat = 0;
double distance;
Animation animRotate;
TextView startStop;

LocationManager lm;

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    this.requestWindowFeature(Window.FEATURE_NO_TITLE);
    setContentView(R.layout.activity_test);
    startStop = (TextView) findViewById(R.id.textView2);
    display = (TextView) findViewById(R.id.textView1);
    start = (Button) findViewById(R.id.button1);
    animRotate = AnimationUtils.loadAnimation(this,
            R.anim.anim_rotate);

lm = (LocationManager) getSystemService(LOCATION_SERVICE); 
lm.removeUpdates(Loclist); 
display.setText("0.0km");

    start.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            if (!doubleclick) {
                lm = (LocationManager) getSystemService(LOCATION_SERVICE);
                enabled = lm
                        .isProviderEnabled(LocationManager.GPS_PROVIDER);
                if (!enabled) {
                    Intent inte = new Intent(
                            Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                    startActivity(inte);
                } else {
                    lm.requestLocationUpdates(lm.GPS_PROVIDER, 0, 0,
                            Loclist);
                    Location loc = lm.getLastKnownLocation(lm.GPS_PROVIDER);

                    if (loc == null) {
                        display.setText("No GPS location found");
                    } else {
                        // set Current latitude and longitude
                        currentLon = loc.getLongitude();
                        currentLat = loc.getLatitude();
                        Log.e("Location", "currentLat:" + currentLat);

                    }
                    // Set the last latitude and longitude
                    startStop.setText("Stop");
                    lastLat = currentLat;
                    lastLon = currentLon;
                    doubleclick = true;
                }
            } else {
                lm.removeUpdates(Loclist);
                startStop.setText("Start");
                v.clearAnimation();
                doubleclick = false;
                Intent in = new Intent(Gps.this, NextActivity.class);
                //in.putExtra("distance", display.toString());
                startActivity(in);
                display.setText("0.0km");
            }

        }
    });
}

LocationListener Loclist = new LocationListener() {

    @Override
    public void onLocationChanged(Location location) {
        // TODO Auto-generated method stub

        // start location manager
        LocationManager lm = (LocationManager) getSystemService(LOCATION_SERVICE);

        // Get last location
        Location loc = lm.getLastKnownLocation(lm.GPS_PROVIDER);

        // Request new location
        lm.requestLocationUpdates(lm.GPS_PROVIDER, 0, 0, Loclist);

        // Get new location
        Location loc2 = lm.getLastKnownLocation(lm.GPS_PROVIDER);

        // get the current lat and long
        currentLat = loc.getLatitude();
        currentLon = loc.getLongitude();


        Location locationA = new Location("point A");
        locationA.setLatitude(lastLat);
        locationA.setLongitude(lastLon);

        Location locationB = new Location("point B");
        locationB.setLatitude(currentLat);
        locationB.setLongitude(currentLon);
        if (lastLat != 0 || lastLon != 0) {
            double distanceMeters = locationA.distanceTo(locationB);

            double distanceKm = distanceMeters / 1000f;

            display.setText(String.format("%.2f Km", distanceKm));
            Constant.distance = (String.format("%.2f Km", distanceKm));
            start.startAnimation(animRotate);
        }

    }

    @Override
    public void onProviderDisabled(String provider) {
        // TODO Auto-generated method stub

    }

    @Override
    public void onProviderEnabled(String provider) {
        // TODO Auto-generated method stub

    }

    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) {
        // TODO Auto-generated method stub

    }

};

@Override
protected void onResume() {
    // TODO Auto-generated method stub
    super.onResume();
    display.setText("0.0km");

}



}

整个课程将是这样的：

 // get the current lat and long
    currentLat = loc2.getLatitude();
    currentLon = loc2.getLongitude();

public class Gps extends Activity {    
TextView display;
Button start;
boolean doubleclick = false;
AnimationDrawable AppNameAnimation;
private boolean enabled;
double currentLon = 0;
double currentLat = 0;
double lastLon = 0;
double lastLat = 0;
double distance;
Animation animRotate;
TextView startStop;

LocationManager lm;

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    this.requestWindowFeature(Window.FEATURE_NO_TITLE);
    setContentView(R.layout.activity_test);
    startStop = (TextView) findViewById(R.id.textView2);
    display = (TextView) findViewById(R.id.textView1);
    start = (Button) findViewById(R.id.button1);
    animRotate = AnimationUtils.loadAnimation(this,
            R.anim.anim_rotate);

lm = (LocationManager) getSystemService(LOCATION_SERVICE); 
lm.removeUpdates(Loclist); 
display.setText("0.0km");

    start.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            if (!doubleclick) {
                lm = (LocationManager) getSystemService(LOCATION_SERVICE);
                enabled = lm
                        .isProviderEnabled(LocationManager.GPS_PROVIDER);
                if (!enabled) {
                    Intent inte = new Intent(
                            Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                    startActivity(inte);
                } else {
                    lm.requestLocationUpdates(lm.GPS_PROVIDER, 0, 0,
                            Loclist);
                    Location loc = lm.getLastKnownLocation(lm.GPS_PROVIDER);

                    if (loc == null) {
                        display.setText("No GPS location found");
                    } else {
                        // set Current latitude and longitude
                        currentLon = loc.getLongitude();
                        currentLat = loc.getLatitude();
                        Log.e("Location", "currentLat:" + currentLat);

                    }
                    // Set the last latitude and longitude
                    startStop.setText("Stop");
                    lastLat = currentLat;
                    lastLon = currentLon;
                    doubleclick = true;
                }
            } else {
                lm.removeUpdates(Loclist);
                startStop.setText("Start");
                v.clearAnimation();
                doubleclick = false;
                Intent in = new Intent(Gps.this, NextActivity.class);
                //in.putExtra("distance", display.toString());
                startActivity(in);
                display.setText("0.0km");
            }

        }
    });
}

LocationListener Loclist = new LocationListener() {

    @Override
    public void onLocationChanged(Location location) {
        // TODO Auto-generated method stub

        // start location manager
        LocationManager lm = (LocationManager) getSystemService(LOCATION_SERVICE);

        // Get last location
        Location loc = lm.getLastKnownLocation(lm.GPS_PROVIDER);

        // Request new location
        lm.requestLocationUpdates(lm.GPS_PROVIDER, 0, 0, Loclist);

        // Get new location
        Location loc2 = lm.getLastKnownLocation(lm.GPS_PROVIDER);

        // get the current lat and long
        currentLat = loc.getLatitude();
        currentLon = loc.getLongitude();


        Location locationA = new Location("point A");
        locationA.setLatitude(lastLat);
        locationA.setLongitude(lastLon);

        Location locationB = new Location("point B");
        locationB.setLatitude(currentLat);
        locationB.setLongitude(currentLon);
        if (lastLat != 0 || lastLon != 0) {
            double distanceMeters = locationA.distanceTo(locationB);

            double distanceKm = distanceMeters / 1000f;

            display.setText(String.format("%.2f Km", distanceKm));
            Constant.distance = (String.format("%.2f Km", distanceKm));
            start.startAnimation(animRotate);
        }

    }

    @Override
    public void onProviderDisabled(String provider) {
        // TODO Auto-generated method stub

    }

    @Override
    public void onProviderEnabled(String provider) {
        // TODO Auto-generated method stub

    }

    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) {
        // TODO Auto-generated method stub

    }

};

@Override
protected void onResume() {
    // TODO Auto-generated method stub
    super.onResume();
    display.setText("0.0km");

}



}

设置：

如果！双击条件

您还可以在onLocationChanged参数中使用location对象，如下所示：

  @Override
    public void onLocationChanged(Location location) {


        // get the current lat and long
        currentLat = location.getLatitude();
        currentLon = location.getLongitude();


        Location locationA = new Location("point A");
        locationA.setLatitude(lastLat);
        locationA.setLongitude(lastLon);

        Location locationB = new Location("point B");
        locationB.setLatitude(currentLat);
        locationB.setLongitude(currentLon);
        if (lastLat != 0 || lastLon != 0) {
            double distanceMeters = locationA.distanceTo(locationB);

            double distanceKm = distanceMeters / 1000f;

            display.setText(String.format("%.2f Km", distanceKm));
            Constant.distance = (String.format("%.2f Km", distanceKm));
            start.startAnimation(animRotate);
        }

    }

编辑：

获取对位置管理器的引用

 Location loc = lm.getLastKnownLocation(lm.GPS_PROVIDER);

Location manager跟踪您可以使用此方法直接获取的最后一个已知位置

 lm.requestLocationUpdates(lm.GPS_PROVIDER, 0, 0, Loclist);

这类似于将侦听器添加到位置更改，因此每次位置更改时，都会调用LocationChange。

现在，您只需单击一个按钮就可以完成此操作，无需再次执行此操作。您的听众已连接，将多次呼叫onLocationChange。

谢谢兄弟。我可以将文字视图设置为0.0km，但我的问题是，当我再次行走时，它会计算出与前一距离的距离。假设前一次是3.50公里，第二次运行后显示为3.51公里，3.52公里……但应该是0.01公里，0.02公里，像这样。对不起，我的英语不好。因此，这些行没有任何用处：Location loc2=lm.getlastnownlocationlm.GPS\u PROVIDER；和Location loc=lm.getlastnownlocationlm.GPS\u提供者；lm.requestLocationUpdateslm.GPS_提供程序，0，0，位置列表；和LocationManager lm=LocationManager getSystemServiceLOCATION\u服务；你能告诉我为什么我使用Location loc2=lm.getlastnownlocationlm.GPS\u PROVIDER；这条线。我可以使用currentLat=loc2.getLatitude；currentLon=loc2.getLongitude；对于当前lat和lon，这两条线是什么：lastLat=当前lat；lastLon=currentLon；？拆下这些线。正如您已经在onclick listener中所做的那样，这些行没有任何用处：Location loc2=lm.getlastnownlocationlm.GPS\u PROVIDER；和Location loc=lm.getlastnownlocationlm.GPS\u提供者；lm.requestLocationUpdateslm.GPS_提供程序，0，0，位置列表；和LocationManager lm=LocationManager getSystemServiceLOCATION\u服务；在onLocationChanged内部，您可以通过调用getLastKnownLocation获得与您获得的相同的新位置，因此您不需要再次执行此操作。这意味着onLocationChanged location和location loc2的参数=lm.getLastKnownLocationlm.GPS\u；是相同的吗？在onlocationchanged中，两个位置对象的值都相同。您能告诉我onlocationchanged中的前四行是指我的活动吗？对不起，这个问题问得不好。

 lm.requestLocationUpdates(lm.GPS_PROVIDER, 0, 0, Loclist);