C# convert System.Drawing.Bitmap to System.Windows.Media.Imaging.BitmapImage

private BitmapImage ConvertBitmapToBitmapImage(System.Drawing.Bitmap bitmap)
{
    BitmapImage bmi = new BitmapImage();

    using (MemoryStream ms = new MemoryStream())
    {
        bitmap.Save(ms, ImageFormat.Png);
        bmi.BeginInit();
        bmi.StreamSource = ms;
        bmi.CacheOption = BitmapCacheOption.OnLoad;
        bmi.EndInit();
        if (bmi.CanFreeze)
        {
            bmi.Freeze();
        }
    }
    return bmi;
}

using System;
using System.Collections.Generic;
using System.Drawing.Imaging;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace WpfApp41
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            this.WindowState = WindowState.Maximized;
            this.Loaded += MainWindow_Loaded;
        }

        private void MainWindow_Loaded(object sender, RoutedEventArgs e)
        {
            string pngFile = @"../../1.png";
            System.Windows.Controls.Image img = new System.Windows.Controls.Image();
            using (FileStream fs = new FileStream(pngFile, FileMode.OpenOrCreate))
            {
                System.Drawing.Bitmap bitmap = new System.Drawing.Bitmap(fs);
                img.Source = ConvertBitmapToBitmapImage(bitmap);
            }
            this.Content = img;
        }

        private BitmapImage ConvertBitmapToBitmapImage(System.Drawing.Bitmap bitmap)
        {
            BitmapImage bmi = new BitmapImage();

            using (MemoryStream ms = new MemoryStream())
            {
                bitmap.Save(ms, ImageFormat.Png);
                bmi.BeginInit();
                bmi.StreamSource = ms;
                bmi.CacheOption = BitmapCacheOption.OnLoad;
                bmi.EndInit();
                if (bmi.CanFreeze)
                {
                    bmi.Freeze();
                }
            }
            return bmi;
        }
    }
}