WPF: Getting Started

Setup

Install nuget package MagicMvvm.Wpf

$ dotnet add package MagicMvvm.Wpf

Prepare application startup class

Install nuget package then navigate to App.xaml and remove line which starts with StartupUri

<Application x:Class="SampleWpf.App"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:local="clr-namespace:SampleWpf">
</Application>

Override OnStartup method in App.xaml.cs then create object of main view (usually it is MainWindow) or you can resolve it if you use container.

Example code without container support.

public partial class App : Application
{    
    protected override void OnStartup(StartupEventArgs e)
    {
        var mainWindow = new MainWindow(new MainWindowViewModel());
        mainWindow.Show();
        base.OnStartup(e);
    }
}

Example code with container support. Used DryIoc container.

public partial class App : Application
{    
    public static readonly IContainer Container = new Container();

    protected override void OnStartup(StartupEventArgs e)
    {
        RegisterTypes();

        var mainWindow = Container.Resolve<MainWindow>();
        mainWindow.Show();
        base.OnStartup(e);
    }

    // Register all types inside this method
    protected virtual void RegisterTypes()
    {
        // Register views
        Container.Register<MainWindow>(Reuse.Singleton);

        // Register view models
        Container.Register<MainWindowViewModel>(Reuse.Singleton);
    }
}

View models

Create view model class then inherit abstract class ViewModelBase Inside ViewModelBase defined set of methods such as a SetProperty() method changes value of backing field then raises propery changed event.

public class MainWindowViewModel : ViewModelBase
{
    public MainWindowViewModel()
    {
        Message = "Welcome to MagicMvvm";
    }

    private string _message;
    public string Message
    {
        get => _message;
        set => SetProperty(ref _message, value); // Raises on property changed event
    }
}

Binding view models to view

Example code demonstrates binding view model of MainWindow without contianer support.

// MainWindow.xaml.cs file
public partial class MainWindow : Window
{
    public MainWindow(MainWindowViewModel viewModel)
    {
        DataContext = viewModel;
        InitializeComponent();
    }
}

If you use container then you need to do a bit extra work. Due to IoC container agnostic feature, injecting types inside constructor of the view object is NOT supported. In order to bind view model to view object, you need to create static instance of container in App.xaml.cs then resolve view model objects inside view constructor. Below sample code demonstrates this approach.

// MainWindow.xaml.cs file
public partial class MainWindow : Window
{
    // It is important to keep parameterless constructor of view object, if you use IoC container.
    // This restriction applicable only for view objects.
    public MainWindow()
    {
        // Resolve view model then bind to data context
        DataContext = App.Container.Resolve<MainWindowViewModel>(); 
        InitializeComponent();
    }
}