如何在c#背后的代码中打开弹出窗口

using System;
using System.Windows.Forms;

namespace WindowsFormsApp
{
    public partial class MainForm : Form
    {
        public MainForm()
        {
            InitializeComponent();
        }

        private void openButton_Click(object sender, EventArgs e)
        {
            PopupForm popupForm = new PopupForm();
            popupForm.ShowDialog();
        }
    }

    public class PopupForm : Form
    {
        public PopupForm()
        {
            InitializeComponent();
        }

        private void InitializeComponent()
        {
            this.Text = "Popup Form";
            this.Size = new System.Drawing.Size(300, 200);
            // 添加其他控件和逻辑
        }
    }
}

using System;
using System.Windows;

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

        private void openButton_Click(object sender, RoutedEventArgs e)
        {
            PopupWindow popupWindow = new PopupWindow();
            popupWindow.ShowDialog();
        }
    }

    public class PopupWindow : Window
    {
        public PopupWindow()
        {
            InitializeComponent();
        }

        private void InitializeComponent()
        {
            this.Title = "Popup Window";
            this.Width = 300;
            this.Height = 200;
            // 添加其他控件和逻辑
        }
    }
}