LocationListener 没有提供任何速度更新

Posted 2023-04-14

【中文标题】LocationListener 没有提供任何速度更新

【英文标题】：LocationListener not giving any speed updates

【发布时间】：2018-03-26 09:29:03

【问题描述】：

我正在尝试使用LocationListener 获取我的 GPS 速度。

我在第一次启动应用程序时请求许可，然后授予许可，“onLocationChanged()”立即显示祝酒词，但不再显示。

我在手机上激活了位置信息。 但我没有收到更多位置更新。

我很抱歉倾倒了我所有的代码，但我不确定要显示什么。

有人知道我在这里缺少什么吗？

package com.example.username.yaddayadda;

import android.Manifest;
import android.annotation.TargetApi;
import android.app.Activity;
import android.content.Context;
import android.content.pm.PackageManager;
import android.location.Location;
import android.location.LocationManager;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.TextView;
import android.location.GpsStatus;
import android.location.LocationListener;
import android.location.Location;
import android.widget.Toast;
import java.util.Formatter;
import java.util.Locale;

@TargetApi(23)
public class MainActivity extends Activity implements LocationListener

@Override
protected void onCreate(Bundle savedInstanceState) 
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    LocationManager locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);

    try 
        if (checkIfPermissionIsGranted())
            Toast toast = Toast.makeText(getApplicationContext(), "Permission is granted for fine and coarse location", Toast.LENGTH_LONG);
            toast.show();
            locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this);
            locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, this);
        
        else 
            ActivityCompat.requestPermissions(this, new String[] 
                            Manifest.permission.ACCESS_FINE_LOCATION,
                            Manifest.permission.ACCESS_COARSE_LOCATION ,
                    1);

            if(checkIfPermissionIsGranted())
                Toast toast = Toast.makeText(getApplicationContext(), "Permission was granted for fine and coarse location", Toast.LENGTH_LONG);
                toast.show();

                locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this);
                locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, this);
             else 
                Toast toast = Toast.makeText(getApplicationContext(), "Permission was denied for fine and coarse location", Toast.LENGTH_LONG);
                toast.show();
            
        
     catch(SecurityException e)
        Context context = getApplicationContext();
        CharSequence text = "Got exception: \n" + e.getMessage();
        int duration = Toast.LENGTH_LONG;

        Toast toast = Toast.makeText(context, text, duration);
        toast.show();
    
    this.onLocationChanged(null);


private boolean checkIfPermissionIsGranted()
    return (ContextCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED
            && ContextCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_GRANTED);


@Override
public void onLocationChanged(Location location) 
    TextView txt = (TextView) this.findViewById(R.id.txtCurrentSpeed);
    Toast toast = Toast.makeText(getApplicationContext(), "onLocationChanged()", Toast.LENGTH_SHORT);
    toast.show();

    if(location==null)
        txt.setText("-.- m/s");
    
    else 
        if(location.hasSpeed())
            float nCurrentSpeed = location.getSpeed();
            txt.setText(nCurrentSpeed + " m/s");
         else 
            txt.setText("0.0 m/s");
        
    


@Override
public void onStatusChanged(String provider, int status, Bundle extras) 
    Toast toast = Toast.makeText(getApplicationContext(), "onStatusChanged()", Toast.LENGTH_SHORT);
    toast.show();


@Override
public void onProviderEnabled(String provider) 
    Toast toast = Toast.makeText(getApplicationContext(), "onProviderEnabled()", Toast.LENGTH_SHORT);
    toast.show();


@Override
public void onProviderDisabled(String provider) 
    Toast toast = Toast.makeText(getApplicationContext(), "onProviderdisabled()", Toast.LENGTH_SHORT);
    toast.show();

【参考方案1】：

“onLocationChanged()”立即显示祝酒词，但不再显示。

您没有收到任何位置更新，但您在此处自己调用此函数

// toast because of this , so no need of this , remove this call
this.onLocationChanged(null); 

但是我没有更多的位置更新。

因为第一次，您拥有权限，然后在授予权限后，您需要再次从onRequestPermissionsResult 执行位置请求代码。

所以你需要覆盖onRequestPermissionsResult，一旦你获得了权限，然后requestLocationUpdates就像

@Override
public void onRequestPermissionsResult(int requestCode,
                                       String permissions[], int[] grantResults) 
    switch (requestCode) 
        case 1: 
            // If request is cancelled, the result arrays are empty.
            if (grantResults.length > 0
                    && grantResults[0] == PackageManager.PERMISSION_GRANTED) 

                // permission was granted, yay! Do the
                // location-related task you need to do.
                if (ContextCompat.checkSelfPermission(this,
                        Manifest.permission.ACCESS_FINE_LOCATION)
                        == PackageManager.PERMISSION_GRANTED) 

                    //Request location updates:
                    locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 10, 1000*60, this);
                

             else 

                // permission denied, Disable the
                // functionality that depends on this permission.
            
            return;
        

    

注意：向两个提供商请求位置是理想的，只需使用最好的一个，您可以将您的位置请求代码移动到单独的函数中，并在需要时调用它。

参考

getBestLocation()

【讨论】：

谢谢！ onRequestPermissionsResult 是我需要的！

@Starstepper 我很高兴能帮上忙，编码愉快