【发布时间】：2016-08-11 11:26:31
【问题描述】：
我正在开发一个应用程序并使用以下代码获取用户的当前坐标（来自this 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();
}
});
问题在于，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 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！
这怎么会发生？这是怎么回事？？？？
请告诉我。
P.S.：此问题仅在 Android M 及以上版本中出现。
【问题讨论】：
-
它上面的 toast 在一个接口方法中。我相信只有在回调到达时才会调用它
-
@Shaishav 你到底是什么意思？此代码是否需要时间返回位置？我应该怎么做才能确保必须检索一些经纬度？
-
是的...我什至不知道那个界面，所以我无法评论如何让它变得更快。但是，请注意，它只会在回调到达时被调用。如果您想在任何情况下显示它，请将其放在接口方法之外（就像您的其他吐司一样）
-
哈哈.. 我的主要目的不是显示
Toast。就是获取坐标。有没有更好的方法？ -
我相信这需要一些时间。我不知道您的用例，但我有一种感觉，如果您也将另一个 toast 移动到方法中，它们只会在合法数据出现时一个接一个地出现（假设这是您的用户想要的）
标签： android gps android-6.0-marshmallow runtime-permissions android-reactivelocation