android-mvvm

问题 I am using an MVVM architechture to build a simple ordering app. I am using a RecyclerView in my ProductsFragment to list all the products that can be ordered. I am also using LiveData in my ViewModel and observable in my Fragment to check for any changes to the List of products. In my list item I have 3 buttons: 1 button to add a product to the basket, another to increment the quantity that customer wants to add to the basket and a third to decrement the quantity the customer wants to add to

问题 I am trying to check that if user is logged on or not. If yes then show a specific view group otherwise show different view group. To check whether user is logged on or not I am fetching the user from shared preference (at the time of login user is saved in shared preference). Let me show my code. SplashViewModel public class SplashViewModel extends ViewModel { public final String TAG = "SplashViewModel"; private final String GREETING = "Hi "; public ObservableBoolean isLoggedIn = new

问题 I'm using MVVM and rxJava and retrofit to send my request. I have a bottom navigation view which has 5 fragments and in one of them, I have to send a request and after it, the response is delivered, I have to send another request to my server. this is my ViewModel class : class MyViewModel: ViewModel() { val compositeDisposable = CompositeDisposable() val myFirstReqLiveData = MutableLiveData<myFirstReqModel>() val mySecondReqLiveData = MutableLiveData<mySecondReqModel>() fun getFirstReq(token

问题 I am in the following scenario: I have an OnboardActivity which contains a ViewModel , I can rotate this OnboardActivity many times and the ViewModel persist across configuration changes without issues. However, if I launch another Activity(FirebaseAuthActivity) on top of this one ( OnboardActivity ) with startActivityForResult(...) , and then in FirebaseAuthActivity I rotate the device and press the back button. When the OnboardActivity is brought to the top of the stack it recreates the

问题 I checked this article but observe the response changes in MainActivity. Here is my code for LoginRepo public MutableLiveData<LoginResponseModel> checkLogin(LoginRequestModel loginRequestModel) { final MutableLiveData<LoginResponseModel> data = new MutableLiveData<>(); Map<String, String> params = new HashMap<>(); params.put("email", loginRequestModel.getEmail()); params.put("password", loginRequestModel.getPassword()); apiService.checkLogin(params) .enqueue(new Callback<LoginResponseModel>()

问题 I copied an example of MVVM with Android Architecture Components, Retrofit, Dagger, and data binding. I am using this code as a starting point to my app in order to start using better architectures in Android app development. However, take these codes: interface ViewModelInjector { /** * Injects required dependencies into the specified PostListViewModel. * @param postListViewModel PostListViewModel in which to inject the dependencies */ fun inject(postListViewModel: PostListViewModel)

问题 When I try to set the onClick method in my Google's SignInButton : android:onClick="@{() -> viewModel.onGoogleLoginClick()}" I always get this error: Found data binding errors. ****/ data binding error ****msg:Cannot find the proper callback class for android:onClick. Tried android.view.View but it has 0 abstract methods, should have 1 abstract methods. file:/Users/user/Android/project/app/src/main/res/layout/activity_login.xml loc:53:31 - 53:66 ****\ data binding error **** Here is my code:

问题 I am not able to parse json data from remote server. I am using MVVM architecture and volley library to parse json data. I tried to debug and the message says "An attempt to invoke virtual method has been made on a null object reference". I thought that the problem is due to LiveData class, so i removed it. Then, also it's not working. Please, also tell how to use LiveData class. BikesRepository.java package com.example.osama.dashbike.Repository; import android.content.Context; import com

问题 I have this ViewModel that gets a list from the network and I populate a RecyclerView with the data ( MyAvailabilityRepository returns a MutableLiveData , that's why i'm using Transformations.switchMap ): class MyAvailabilityViewModel : ViewModel() { private val getListsParams = MutableLiveData<String>() private val getListsObservable = Transformations.switchMap(getListsParams) { organizationId -> MyAvailabilityRepository.getSectionedLists(organizationId) } fun getListsObservable() : LiveData

问题 Looking through the samples I seen 2 approaches to MVVM using Android Architecture Components. First approach: ViewModel provides LiveData Activity subscribes to LiveData When observer called Activity is setting data to ViewModel ObservableField . Whole ViewModel is passed to binding. In xml you just set ObservableField as value <ProgressBar android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center" app:visibleGone="@{viewmodel.listLoading}"/>