《C#高级编程》读书笔记（二十）：核心XAML

1，关于XAML

编写 WPF 应用程序、使用 WF、创建 XPS 文档 、编写 Silverlight 或者 Windows 8 应用程序，就还需要 XAML。XAML(eXtensible Application Markup Lauguage，可扩展应用程序标记语言)是一种声明性的 XML 语法。

XAML 代码使用文本XML来声明。XAML 代码可以使用设计器创建，也可以手动编写。

2，将元素映射到.NET对象上

创建C#控制台项目，引用程序集 PresentationFramework、PresentationCore、WindowBase 和 System.Xaml。

using System;
using System.Windows;
using System.Windows.Controls;

namespace ConsoleXAML
{
    class Program
    {
        [STAThread]
        static void Main(string[] args)
        {
            var b = new Button()
            {
                Content = "Click Me!"
            };
            var w = new Window()
            {
                Title = "Code Demo",
                Content = b
            };

            var app = new Application();
            app.Run(w);
        }
    }
}

3，使用自定义.NET 类

namespace XAMLIntro
{
    public class Person
    {
        public string FirstName { get; set; }
        public string LastName { get; set; }

        public override string ToString()
        {
            return $"{FirstName} {LastName}";
        }
    }
}

<Window x:Class="XAMLIntro.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:XAMLIntro"
        mc:Ignorable="d"
        Title="MainWindow" Height="350" Width="525">
    <Grid>
        <Button Content="Click Me!" Height="20" Width="100"
                Background="LightGoldenrodYellow" Click="Button_Click"></Button>
        <ListBox Margin="193,35,194,204">
            <local:Person FirstName="Stephanie" LastName="Nagel"></local:Person>
            <local:Person FirstName="Matthias" LastName="Nagel"></local:Person>
        </ListBox>
        <Button Margin="208,198,201,93" HorizontalAlignment="Center" VerticalAlignment="Center">
            Click Test!
        </Button>
    </Grid>
    <!--<x:Array Type="local:Person">
        <local:Person FirstName="Stephanie" LastName="Nagel"></local:Person>
        <local:Person FirstName="Matthias" LastName="Nagel"></local:Person>
    </x:Array>-->
</Window>

4，事件的冒泡和隧道

元素可以包含在其他元素中。内层元素的事件可以传递到外部，这就冒泡事件。外部向内部移动，叫隧道事件。WPF 支持事件的冒泡和隧道。

<Window x:Class="ButtleDemo.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:ButtleDemo"
        mc:Ignorable="d"
        Title="MainWindow" Height="350" Width="525">
   <StackPanel x:Name="StackPanel1" Button.Click="OnOuterButtonClick">
       <Button x:Name="Button1" Content="Button 1" Margin="5,15,5,5"></Button>
        <Button x:Name="Button2"  Margin="5" Click="OnButton2">
            <ListBox x:Name="ListBox1">
                <Button x:Name="InnerButton1" Content="Inner Button 1" Margin="4" Padding="4" Click="OnInner1"></Button>
                <Button x:Name="InnerButton2" Content="Inner Button 2" Margin="4" Padding="4" Click="OnInner2"></Button>
            </ListBox>
        </Button>
       <ListBox ItemsSource="{Binding}"></ListBox>
    </StackPanel>
</Window>

using System.Collections.ObjectModel;
using System.Windows;

namespace ButtleDemo
{
    /// <summary>
    /// MainWindow.xaml 的交互逻辑
    /// </summary>
    public partial class MainWindow : Window
    {
        private ObservableCollection<string> messages = new ObservableCollection<string>();
        public MainWindow()
        {
            InitializeComponent();
            this.DataContext = messages;
        }

        private void AddMessage(string message, object sender, RoutedEventArgs e)
        {
            messages.Add(
                $"{message}," +
                $"sender:{(sender as FrameworkElement).Name};" +
                $"source:{(e.Source as FrameworkElement).Name};" +
                $"original source:{(e.OriginalSource as FrameworkElement).Name}");
        }

        private void OnOuterButtonClick(object sender, RoutedEventArgs e)
        {
            AddMessage("最外层单击", sender, e);
        }

        private void OnButton2(object sender, RoutedEventArgs e)
        {
            AddMessage("Button2单击",sender,e);
            e.Source = sender;
        }

        private void OnInner1(object sender, RoutedEventArgs e)
        {
            AddMessage("Inner 1 Click!",sender,e);
        }

        private void OnInner2(object sender, RoutedEventArgs e)
        {
            AddMessage("Inner 2 Click!", sender, e);
            e.Handled = true;
        }
    }
}