WPF Window or Control での初期表示とか

コンストラクタでごにょごにょやるのは嫌だ

Views/MainWindow

<Window x:Class="WpfApp2.Views.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfApp2"
        xmlns:prism="http://prismlibrary.com/"
        xmlns:i="http://schemas.microsoft.com/xaml/behaviors"
        mc:Ignorable="d"
        prism:ViewModelLocator.AutoWireViewModel="True"
        Title="MainWindow" Height="450" Width="800">
    <i:Interaction.Triggers>
        <i:EventTrigger EventName="Loaded">
            <i:InvokeCommandAction Command="{Binding LoadedCommand}" />
        </i:EventTrigger>
    </i:Interaction.Triggers>
    <Grid>
        <TextBlock Text="{Binding Message.Value}"></TextBlock>
    </Grid>
</Window>

ViewModels/MainWindowViewModel

using Prism.Mvvm;
using Reactive.Bindings;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace WpfApp2.ViewModels
{
    internal class MainWindowViewModel : BindableBase
    {
        public ReactiveCommand LoadedCommand { get; set; } = new ReactiveCommand();
        public ReactiveProperty<string> Message { get; set; } = new ReactiveProperty<string>();
        public MainWindowViewModel()
        {
            LoadedCommand.Subscribe(() => {
                Message.Value = $"Loaded {DateTime.Now:yyyy/MM/dd HH:mm:ss}";
            });
        }
    }
}

前に同じような記事を書いた気がするのはきっと気のせい。