我正在开发一款应用程序，其中需要GPS来检测用户的当前位置并继续进行。因此，我正在使用此代码：isGPSEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);来检测GPS是否打开，并提示用户在关闭时将其打开。这段代码完全可以检测到它是否关闭，但是当我打开GPS并尝试继续前进时。以上代码未能检测到GPS已开启并提示用户再次打开GPS即使它已开启。
以下是打开GPS后我正在尝试进一步的方法：
public void btnRetryGpsEvents() {
if (isGPSEnabled) {
ReactiveLocationProvider locationProvider = new ReactiveLocationProvider(getBaseContext());
locationProvider.getLastKnownLocation()
.subscribe(new Action1<Location>() {
@Override
public void call(Location location) {
currentLatDouble = location.getLatitude();
currentLngDouble = location.getLongitude();
}
});
Handler handler = new Handler();
handler.postDelayed(new Runnable() {
@Override
public void run() {
if (currentLatDouble != null || currentLngDouble != null) {
retrieveHWrapper();
btnRetryGps.setVisibility(View.INVISIBLE);
gps_off.setVisibility(View.INVISIBLE);
Toast.makeText(getBaseContext(), "Loading h-requests...", Toast.LENGTH_LONG).show();
} else {
gps_off.setVisibility(View.VISIBLE);
progressBarLoadingRequests.setVisibility(View.INVISIBLE);
btnRetryGps.setVisibility(View.VISIBLE);
btnRetryGps.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
btnRetryGpsEvents();
}
});
}
}
}, 2000);
} else {
AlertDialog.Builder alertDialog = new AlertDialog.Builder(MainActivity.this);
// Setting Dialog Title
alertDialog.setTitle("GPS settings");
// Setting Dialog Message
alertDialog.setMessage("GPS is not enabled. Enable it in settings menu.");
// On pressing Settings button
alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
startActivity(intent);
}
});
// on pressing cancel button
alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
// Showing Alert Message
alertDialog.show();
gps_off.setVisibility(View.VISIBLE);
progressBarLoadingRequests.setVisibility(View.INVISIBLE);
btnRetryGps.setVisibility(View.VISIBLE);
btnRetryGps.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
btnRetryGpsEvents();
}
});
}
}
我已经在onCreate（）方法中请求了许可：
int hasWriteContactsPermission = ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE) & ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.ACCESS_FINE_LOCATION) & ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.ACCESS_COARSE_LOCATION) & ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.WRITE_SETTINGS);
if (hasWriteContactsPermission != PackageManager.PERMISSION_GRANTED) {
if (ActivityCompat.checkSelfPermission(getBaseContext(), Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(getBaseContext(), Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(getBaseContext(), Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(getBaseContext(), Manifest.permission.WRITE_SETTINGS) != PackageManager.PERMISSION_GRANTED) {
// TODO: Consider calling
// ActivityCompat#requestPermissions
// here to request the missing permissions, and then overriding
// public void onRequestPermissionsResult(int requestCode, String[] permissions,
// int[] grantResults)
// to handle the case where the user grants the permission. See the documentation
// for ActivityCompat#requestPermissions for more details.
if (!ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE) && !ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this, Manifest.permission.ACCESS_FINE_LOCATION) && !ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this, Manifest.permission.ACCESS_COARSE_LOCATION) && !ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this, Manifest.permission.WRITE_SETTINGS)) {
showMessageOKCancel("You need to allow access to few permissions so that the app can work as expected.",
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION, Manifest.permission.WRITE_SETTINGS},
REQUEST_RUNTIME_PERMISSION);
}
});
return;
}
ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION, Manifest.permission.WRITE_SETTINGS},
REQUEST_RUNTIME_PERMISSION);
return;
}
}
所以，最重要的是，即使在打开GPS并点击“重试”按钮之后，当GPS开启时应该执行的代码也没有被执行！
这里出了什么问题？
请告诉我。
答案 0 :(得分：1)
也许你的布尔值仍然返回false，因为你没有执行重新检查。你可以通过替换重试函数isGPSEnabled中的条件来做到这一点，我认为它仍然返回true。这样做：
public void btnRetryGpsEvents() {
if (locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)) {
ReactiveLocationProvider locationProvider = new ReactiveLocationProvider(getBaseContext());
locationProvid//... REST OF YOUR CODE ...//
顺便说一句，您应该知道isProviderEnabled标志只会在打开GPS后一段时间后返回true，而不是立即返回。这是因为设备仍然必须连接到GPS卫星或网络，以指示提供商已启用。因此，建议在打开设备的GPS后检查并重新检查服务可用性，直到您建立连接。另外，我用它进行初步检查：
LocationManager locationManager;
locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
if (!locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER)) {
// TODO Execute code if provider is not available. Also check for network connection
}