3.只使用代码创建WPF应用程序

using System.Windows;
using System.Windows.Controls;
using System.Windows.Markup;
namespace WpfApp
{
    internal class Windows1:Window
    {
        private Button button1;
        public Windows1()
        {
            InitializeComponent();
        }
        private void InitializeComponent()
        {
            //设置窗体
            this.Width = 285;
            this.Height = 285;
            this.Left = this.Top = 100;
            this.Title = "Code-Only Window";
            //创建停靠面板对象
            DockPanel panel = new DockPanel();
            //创建按钮对象
            button1 = new Button();
            button1.Content = "Please click me.";
            button1.Margin = new Thickness(30);
            button1.Click += button1_Click;
            IAddChild container= panel;
            container.AddChild(button1);
            container = this;
            container.AddChild(panel);
        }
        private void button1_Click(object sender, RoutedEventArgs e)
        {
            button1.Content = "Thank you";
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
namespace WpfApp
{
    internal class Program:Application
    {
        [STAThread()]
        static void Main()
        {
            Program app = new Program();
            app.MainWindow=new Windows1();
            app.MainWindow.ShowDialog();
        }
    }
}