viewmodel

问题 In the summer of last year I started refactoring my Android application with Android's architecture components (Room, ViewModel, LiveData). I have two Room repositories, one of them is accessed by multiple views (fragments) of the application. Because of that I used an AndroidViewModel , which has access to this repository and which is initialized in my MainActivity . new ViewModelProvider(this).get(CanteensViewModel.class); In my two fragments I accessed this ViewModel by new

问题 The default behavior of DataGridCheckBoxColumn is that the user has to click twice to change the checkbox value. In the How to perform Single click checkbox selection in WPF DataGrid topic there are a couple of solutions which work, but there is a problem - is you have a viewmodel object in code behind, which implements the IEditableObject interface, then the EndEdit method doesn't execute. Any idea how to make single click work and also preserve the IEditableObject functionallity? 回答1: You

问题 I have a SwiftUI (Beta 5) view with an attached ViewModel. I want to navigate to it via a navigationLink and pass in a simple parameter (called FSAC in this case) I navigate using NavigationLink("Next", destination: MyTestView(FSAC: "testFsac")) The view has an FSAC Property with willSet and didSet property observer struct MyTestView: View { @ObservedObject var vm = MyTestViewModel() var FSAC: String { willSet { print("will set fsac") } didSet { print("did set fsac") vm.FSAC = FSAC } } var

问题 I have a SwiftUI (Beta 5) view with an attached ViewModel. I want to navigate to it via a navigationLink and pass in a simple parameter (called FSAC in this case) I navigate using NavigationLink("Next", destination: MyTestView(FSAC: "testFsac")) The view has an FSAC Property with willSet and didSet property observer struct MyTestView: View { @ObservedObject var vm = MyTestViewModel() var FSAC: String { willSet { print("will set fsac") } didSet { print("did set fsac") vm.FSAC = FSAC } } var

问题 I want to initialize ViewModel in Activity using androidx library I have tried what documentation says but it is not working. the ".of" is not resolved. import androidx.appcompat.app.AppCompatActivity import android.os.Bundle import androidx.databinding.DataBindingUtil import androidx.lifecycle.ViewModelProvider import com.example.myapplication.databinding.ActivityMainBinding class MainActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate

问题 My question based on InventorySampleApp by Microsoft. The ServiceLocator contains method Configure() that register Services and ViewModels. With method GetService<T>() we can get it. For example, ProductView.cs : ViewModel = ServiceLocator.Current.GetService<ProductDetailsViewModel>(); Each *ViewModel contains constructor with interface, for example: public ProductDetailsViewModel(IProductService productService, IFilePickerService filePickerService, ICommonServices commonServices) I can't

问题 I have recently seen a weird issue that is acting as a barrier to my project. Multiple calls to set the live data value does not invoke the observer in the view. It seems that only the last value that was set actually invokes the Observer in the view. Here is the code snippet for a review. MainActivity.kt class MainActivity : AppCompatActivity() { private lateinit var viewModel: MainViewModel override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState)

问题 I have recently seen a weird issue that is acting as a barrier to my project. Multiple calls to set the live data value does not invoke the observer in the view. It seems that only the last value that was set actually invokes the Observer in the view. Here is the code snippet for a review. MainActivity.kt class MainActivity : AppCompatActivity() { private lateinit var viewModel: MainViewModel override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState)

问题 Below is XML equivalent of what I'm trying to achieve, but without XML <Button android:id="@+id/bt_start" android:onClick="@{() -> vm.onClickedStart()}" android:text='@{vm.btStartLbl}' /> so if I have: ConstraintLayout cl = findViewById(R.id.cl); Button btn = new Button(MyActivity.this); btn.setText("How to Data Bind here?"); btn.setOnClickListener(new OnClickListener (){ /* how to databind here? */ }); cl.addView(btn); how to databind it as equivalent as xml above? is it possible? 回答1: For

问题 I don't think I understand the MVVM pattern properly because having a Model and ViewModel class seems redundant to me. My understanding of the Model is to basically add in minor details of a class and let the ViewModel handle all the logic and implementation. If that is the case why separate the two? Couldn't you create the variables, properties and such in the view model and still have the logic in there? To me it sounds like C++ in a way. You have the header file which describes the class