Как правильно открыть окно в другом приложении?

public void StartNewTestWindow()
{
    var window = new TestWindow { Owner = this };
    window.Show();
    WinApi.SetForegroundWindow(window.Handle());
}

<Window x:Class="SfwTest.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="Set Foreground Window Test" Width="525"
        SizeToContent="Height"
        Background="{x:Static SystemColors.ControlBrush}">
    <StackPanel>
        <Label>Указатель этого окна:</Label>
        <TextBox x:Name="MyHandle" IsReadOnly="True" />
        <Label>Указатель другого окна:</Label>
        <TextBox x:Name="AnotherHandle" />
        <Button x:Name="Go" Click="Go_Click">Set Foreground Window</Button>
    </StackPanel>
</Window>

using System;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Interop;

namespace SfwTest
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();

            this.Loaded += (sender, args) =>
            {
                var myHandle = (int)new WindowInteropHelper(this).Handle;
                MyHandle.Text = myHandle.ToString();
            };
        }

        [DllImport("user32.dll")]
        static extern bool SetForegroundWindow(IntPtr hWnd);
        
        private void Go_Click(object sender, RoutedEventArgs e)
        {
            try
            {
                var text = AnotherHandle.Text.Trim();
                if (String.IsNullOrEmpty(text))
                    throw new ArgumentNullException("Указатель другого окна");

                var anotherHandle = (IntPtr)int.Parse(text);
                SetForegroundWindow(anotherHandle);
            }
            catch (Exception ex)
            {
                AnotherHandle.Focus();
                MessageBox.Show(this, ex.Message, "Ошибка", MessageBoxButton.OK, MessageBoxImage.Error);
            }
        }
    }
}