WPF OpenFileDialog 与 MVVM 模式 [复制]

XAML
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:MVVMOpenFileDialog"
        Title="MainWindow" Height="450" Width="800">
    
        
    
    
        
    

C#
using System.ComponentModel;
using System.Windows.Input;
using Microsoft.Win32;
namespace MVVMOpenFileDialog
{
    public class MainViewModel : INotifyPropertyChanged
    {
        private string selectedFilePath;
        public string SelectedFilePath
        {
            get { return selectedFilePath; }
            set
            {
                selectedFilePath = value;
                OnPropertyChanged(nameof(SelectedFilePath));
            }
        }
        public ICommand OpenFileCommand { get; }
        public MainViewModel()
        {
            OpenFileCommand = new RelayCommand(OpenFile);
        }
        private void OpenFile()
        {
            var openFileDialog = new OpenFileDialog();
            if (openFileDialog.ShowDialog() == true)
            {
                SelectedFilePath = openFileDialog.FileName;
            }
        }
        public event PropertyChangedEventHandler PropertyChanged;
        protected virtual void OnPropertyChanged(string propertyName)
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}