我正在开发一个应用程序并使用以下代码来获取用户的当前坐标（来自这个库）：
ReactiveLocationProvider locationProvider = new ReactiveLocationProvider(getBaseContext());
locationProvider.getLastKnownLocation().subscribe(new Action1<Location>() {
@Override
public void call(Location location) {
currentLatDouble = location.getLatitude();
currentLngDouble = location.getLongitude();
Toast.makeText(getBaseContext(), "User's location retrieved using library for android M in btnRetryGpsEvents()", Toast.LENGTH_SHORT).show();
}
});
问题是即使在所有条件都为真之后，这段代码有时甚至都不会被执行。请看下面的代码：
if (currentLatDouble != null || currentLngDouble != null) {
retrieveHWrapper();
progressBarLoadingRequests.setVisibility(View.VISIBLE);
btnRetryGps.setVisibility(View.INVISIBLE);
gps_off.setVisibility(View.INVISIBLE);
Toast.makeText(getBaseContext(), "Loading hrequests...", 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();
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;
}
}
ReactiveLocationProvider locationProvider = new ReactiveLocationProvider(getBaseContext());
locationProvider.getLastKnownLocation()
.subscribe(new Action1<Location>() {
@Override
public void call(Location location) {
currentLatDouble = location.getLatitude();
currentLngDouble = location.getLongitude();
Toast.makeText(getBaseContext(), "User's location retrieved using library for android M in btnRetryGpsEvents()", Toast.LENGTH_SHORT).show();
}
});
Toast.makeText(getBaseContext(), "called from btnRetryGpsEvents() - GPS available", Toast.LENGTH_SHORT).show();
}
});
}
运行上面的代码后，由于这段代码的 toast 被显示：Toast.makeText(getBaseContext(), "called from btnRetryGpsEvents() - GPS available", Toast.LENGTH_SHORT).show();这意味着它正在被执行，但是它上面的 toast 即：Toast.makeText(getBaseContext(), "User's location retrieved using library for android M in btnRetryGpsEvents()", Toast.LENGTH_SHORT).show();没有显示，这意味着它没有被执行！
这怎么可能发生？这里怎么了？？？
请告诉我。
PS：这个问题只在Android M及以上出现。