我已经寻找了类似的问题，他们都没有包括catlog，所以没有人能真正帮助他们。我把它放在这里，希望你能帮忙！基本上，只要我打开应用程序，它就会提示我一个位置权限，说我会允许它。只要我点击是的，应用程序崩溃！
package com.worden.jason.sample;
import android.Manifest;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
public class MainActivity extends AppCompatActivity implements LocationListener {
LocationManager locationManager;
public static final int MY_PERMISSIONS_REQUEST_LOCATION = 99;
String provider;
public void Analysis(View view) {
Intent intent = new Intent(MainActivity.this,Analysis.class);
startActivity(intent);
finish();
}
public void Tips(View view) {
Intent intent = new Intent(MainActivity.this,Tips.class);
startActivity(intent);
finish();
}
public boolean checkLocationPermission() {
if (ContextCompat.checkSelfPermission(this,
Manifest.permission.ACCESS_FINE_LOCATION)
!= PackageManager.PERMISSION_GRANTED) {
// Should we show an explanation?
if (ActivityCompat.shouldShowRequestPermissionRationale(this,
Manifest.permission.ACCESS_FINE_LOCATION)) {
// Show an explanation to the user *asynchronously* -- don't block
// this thread waiting for the user's response! After the user
// sees the explanation, try again to request the permission.
new AlertDialog.Builder(this)
.setTitle(R.string.TileLocation)
.setMessage(R.string.TextLocation)
.setPositiveButton(R.string.Positive, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
//Prompt the user once explanation has been shown
ActivityCompat.requestPermissions(MainActivity.this,
new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
MY_PERMISSIONS_REQUEST_LOCATION);
}
})
.create()
.show();
} else {
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
MY_PERMISSIONS_REQUEST_LOCATION);
}
return false;
} else {
return true;
}
}
@Override
public void onRequestPermissionsResult(int requestCode,
@NonNull String permissions[], @NonNull int[] grantResults) {
switch (requestCode) {
case MY_PERMISSIONS_REQUEST_LOCATION: {
// If request is cancelled, the result arrays are empty.
if (grantResults.length > 0
&& grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// location-related task you need to do.
if (ContextCompat.checkSelfPermission(this,
Manifest.permission.ACCESS_FINE_LOCATION)
== PackageManager.PERMISSION_GRANTED) {
locationManager.requestLocationUpdates(provider, 400, 1, this);
}
} else {
// permission denied, boo! Disable the
}
return;
}
}
}
@Override
public void onLocationChanged(Location location) {
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onProviderDisabled(String provider) {
}
@Override
protected void onResume() {
super.onResume();
if (checkLocationPermission()) {
if (ContextCompat.checkSelfPermission(this,
Manifest.permission.ACCESS_FINE_LOCATION)
== PackageManager.PERMISSION_GRANTED) {
//Request location updates:
locationManager.requestLocationUpdates(provider, 400, 1, this);
}
}
}
}public class MainActivity extends AppCompatActivity implements LocationListener {
LocationManager locationManager;
public static final int MY_PERMISSIONS_REQUEST_LOCATION = 99;
**String GPS_PROVIDER;**
public void Analysis(View view) {
Intent intent = new Intent(MainActivity.this,Analysis.class);
startActivity(intent);
finish();
}
public void Tips(View view) {
Intent intent = new Intent(MainActivity.this,Tips.class);
startActivity(intent);
finish();
}
**@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);**
}
public boolean checkLocationPermission() {
if (ContextCompat.checkSelfPermission(this,
Manifest.permission.ACCESS_FINE_LOCATION)
!= PackageManager.PERMISSION_GRANTED) {
// Should we show an explanation?
if (ActivityCompat.shouldShowRequestPermissionRationale(this,
Manifest.permission.ACCESS_FINE_LOCATION)) {
// Show an explanation to the user *asynchronously* -- don't block
// this thread waiting for the user's response! After the user
// sees the explanation, try again to request the permission.
new AlertDialog.Builder(this)
.setTitle(R.string.TileLocation)
.setMessage(R.string.TextLocation)
.setPositiveButton(R.string.Positive, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
//Prompt the user once explanation has been shown
ActivityCompat.requestPermissions(MainActivity.this,
new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
MY_PERMISSIONS_REQUEST_LOCATION);
}
})
.create()
.show();
} else {
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
MY_PERMISSIONS_REQUEST_LOCATION);
}
return false;
} else {
return true;
}
}
@Override
public void onRequestPermissionsResult(int requestCode,
@NonNull String permissions[], @NonNull int[] grantResults) {
switch (requestCode) {
case MY_PERMISSIONS_REQUEST_LOCATION: {
// If request is cancelled, the result arrays are empty.
if (grantResults.length > 0
&& grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// location-related task you need to do.
if (ContextCompat.checkSelfPermission(this,
Manifest.permission.ACCESS_FINE_LOCATION)
== PackageManager.PERMISSION_GRANTED) {
locationManager.requestLocationUpdates(GPS_PROVIDER, 400, 1, this);
}
} else {
// permission denied, boo! Disable the
}
return;
}
}
}
@Override
public void onLocationChanged(Location location) {
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onProviderDisabled(String provider) {
}
@Override
protected void onResume() {
super.onResume();
if (checkLocationPermission()) {
if (ContextCompat.checkSelfPermission(this,
Manifest.permission.ACCESS_FINE_LOCATION)
== PackageManager.PERMISSION_GRANTED) {
//Request location updates:
locationManager.requestLocationUpdates(GPS_PROVIDER, 400, 1, this);
}
}
}
}
1条答案
按热度按时间zpgglvta1#
这里有两个问题：
1.不初始化
locationManager字段。您对locationManager.requestLocationUpdates的调用将导致NullPointerException。1.不初始化
provider字段。您对locationManager.requestLocationUpdates的调用不喜欢此。要解决第一个问题，请添加以下覆盖：
要解决第二个问题，请丢弃
provider字段，改用LocationManager.GPS_PROVIDER（或LocationManager中定义的其他提供程序之一）。或者初始化provider字段。设置断点并在调试器下运行程序是查找此类问题的好方法。另一种方法是查看日志--我敢打赌，在那里的某个地方有相关的堆栈跟踪。
同时确保您的清单中提到了所需的权限：