android-architecture-components

来源： https://stackoverflow.com/questions/50937116/how-to-handle-back-button-when-at-the-starting-destination-of-the-navigation-com

来源： https://stackoverflow.com/questions/50937116/how-to-handle-back-button-when-at-the-starting-destination-of-the-navigation-com

来源： https://stackoverflow.com/questions/55883370/let-every-observer-only-receive-new-livedata-upon-subscribing-observing

来源： https://stackoverflow.com/questions/49221753/exposing-a-room-database-to-other-apps

问题 I am using the Navigation component to show a DialogFragment ( <dialog...>...</dialog> in the navigation.xml ) and want to know what's the recommended way to close the Dialog. I tried myself and got the following results: 1) dismiss() in DialogFragment : seems to work fine 2) findNavController().navigateUp() : seems to work fine 3) findNavController().navigate(MyDialogFragmentDirections.actionMyDialogFragmentToMyNormalFragment()) : works, but loads a fresh version of the target destination,

问题 Using the @Relation annotation. I can query a one to many relationship using the following: @Dao public interface PostDao { @Query("SELECT * FROM post") List<PostWithComments> getPostWithComments(); } Here are the entities @Entity public class Post { @PrimrayKey private int id; private String title; private String content; } @Entity public class Comment { @PrimrayKey private int id; private int post_id; private String content; private String status; } public class PostWithComments { @Embedded

问题 After learning basics about new architecture components, I decided to apply this knowledge and work a demo project. In this project I have been working with google map. In my navHost fragment, one of the fragment shows google map this way <fragment android:layout_width="match_parent" android:layout_height="match_parent" android:id="@+id/map" android:name="com.google.android.gms.maps.SupportMapFragment"></fragment> from the code I have been trying to get this fragment class, the related code

问题 After learning basics about new architecture components, I decided to apply this knowledge and work a demo project. In this project I have been working with google map. In my navHost fragment, one of the fragment shows google map this way <fragment android:layout_width="match_parent" android:layout_height="match_parent" android:id="@+id/map" android:name="com.google.android.gms.maps.SupportMapFragment"></fragment> from the code I have been trying to get this fragment class, the related code

问题 I am trying to add lifecycle:extensions to my project but i can not make it work . Each time it shows error . Unable to resolve dependency for ':app@debug/compileClasspath': Could not resolve android.arch.lifecycle:extensions:1.1.0. I have already read several threads but could not make it work by the answers given there. Project level gradle is: buildscript { repositories { google() jcenter() } dependencies { classpath 'com.android.tools.build:gradle:3.1.2' } } allprojects { repositories {

问题 I am trying to add lifecycle:extensions to my project but i can not make it work . Each time it shows error . Unable to resolve dependency for ':app@debug/compileClasspath': Could not resolve android.arch.lifecycle:extensions:1.1.0. I have already read several threads but could not make it work by the answers given there. Project level gradle is: buildscript { repositories { google() jcenter() } dependencies { classpath 'com.android.tools.build:gradle:3.1.2' } } allprojects { repositories {