mvvm-light

问题 I have an existing Silverlight 4 application that I am attempting to convert to use the locator pattern and the MVVM-Light library. My understanding is that the MvvmLocator class keeps a reference to each view model and allows you to bind the DataContext of each view to an appropriate ViewModel in the locator. My application uses a navigation frame and hence each page in the app is a UserControl that gets loaded into the Content frame. I can see how easy it is to bind each page view to the

问题 Messenger.Default.Register<OpenWindowMessage>(this, message => { var adventurerWindowVM = SimpleIoc.Default.GetInstance<AdventurerViewModel>(); adventurerWindowVM.Adv = message.Argument; var adventurerWindow = new AdventurerView() { DataContext = adventurerWindowVM }; adventurerWindow.Show(); }); This code is fairly simple; it just opens a new window and sets the DataContext of the new window. The problem I'm having is that if I execute this twice, the content of the first instance will be

问题 i recently started working with MVVM Light and just used the IDialogService for the first time. My ViewModelLocator ServiceLocator.SetLocatorProvider(() => SimpleIoc.Default); // Register the dialog service provided by mvvm light SimpleIoc.Default.Register<IDialogService, DialogService>(); My ViewModel private IRestService _restService; public OrderViewModel (IDialogService dialogService ) { _dialogService = dialogService; } And finally using ShowMessage: await _dialogService.ShowMessage(

问题 I'm trying to define a selected item in a combobox. It working fine if I'm just using a String to declare the selected item but not if using an object. <ComboBox HorizontalAlignment="Left" VerticalAlignment="Top" Width="81" materialDesign:HintAssist.Hint="Woche" Margin="10" ItemsSource="{Binding weekSelection}" DisplayMemberPath="name" SelectedItem="{Binding nodeWeek, Mode=TwoWay}" SelectedValue="name" /> - private week _nodeWeek; public week nodeWeek { get { return _nodeWeek; } set {

问题 So far as I understand, SimpleIoc uses GetInstance method to retrieve an instance of a class that is registered. If the instance doesnt exist, it will create it. However, this instance is cached and always retrieved, which mimics the singleton pattern. My thinking is that there is no need to keep an instance of ViewModel in a memory if there is a small possibility that this ViewModel will be needed twice, so I would like to create new instance of it each time that is needed. If we have are

问题 I have an MVVM application and would like to add Crystal Reports. I have a ViewModel of PatientList and would Like to Bind the Report to an Observable collection of Patients in the ViewModel. the Collection is not appearing in the data sources window. 回答1: I guess you are refering to Crystal-Reports datasource window right? If so - I think you will never find the ObservableCollection there (and I don't know if you can have CR observe the collection) but on the document-class in Crystal-Report

问题 I am creating an application using .Net and MVVM Light and I am having some trouble for RelayCommands. I'm trying to create a RelayCommand which takes in a single argument and passes it to a function within the same ViewModel. However everytime I try and do this I keep getting the following exception: A first chance exception of type 'System.MethodAccessException' occurred in mscorlib.dll My code is below. XAML <TextBlock Style="{StaticResource QueryFormTab}" > <Hyperlink Command="{Binding

问题 Background Hi all SO viewers. I am normally an Android developer, but now I'm developing a cross platform application targeting WPF and Android. That being said, there's practically no info on how to directly do what I want. So, I ended up finding a 3-part blog series that goes in depth on how to develop a Windows-based cross platform MVVM project. As long as I set the PCL to be compatible with Xamarin.Android, any code that doesn't throw an error SHOULD work once I get to the Android side of

问题 In app.xaml, i have an error while defining ViewModelLocator. App launches and runs fine, but it annoys me in Studio. Wondering, what can be a reason. Highlighted line is <vm:ViewModelLocator x:Key="ViewModelLocator" d:IsDataSource="True"/> Error: Error 1 Unable to determine application identity of the caller. If to get inside of vm:ViewModelLocator, there's no sign of errors there. Should i re-check all my viewmodels and add IsoStorage designtime protection? if (!System.ComponentModel

问题 In app.xaml, i have an error while defining ViewModelLocator. App launches and runs fine, but it annoys me in Studio. Wondering, what can be a reason. Highlighted line is <vm:ViewModelLocator x:Key="ViewModelLocator" d:IsDataSource="True"/> Error: Error 1 Unable to determine application identity of the caller. If to get inside of vm:ViewModelLocator, there's no sign of errors there. Should i re-check all my viewmodels and add IsoStorage designtime protection? if (!System.ComponentModel