WPF窗体事件响应

    /*记录我学习事件的过程*/

   为降低代码的耦合性，通常将事件“上抛”，由父窗体处理事件；具体的思路是：

  以下为自己写的Demo，实现的是：当按下左Shift、左Ctrl切换颜色

using System;
using System.Collections.Generic;
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 EventTest
{
    /// <summary>
    /// UserControl1.xaml 的交互逻辑
    /// </summary>
    public partial class UserControl1 : UserControl
    {
        public UserControl1()
        {
            InitializeComponent();
            
        }
        public event EventHandler<KeyEventArgs> OnAltKeyUp;

        private void UserControl_KeyUp(object sender, KeyEventArgs e)
        {
            if(OnAltKeyUp!=null)
                OnAltKeyUp(sender, e);
        } 
    }
}

***************************************************

using System;
using System.Collections.Generic;
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 EventTest
{
    /// <summary>
    /// UserControl2.xaml 的交互逻辑
    /// </summary>
    public partial class UserControl2 : UserControl
    {
        public UserControl2()
        {
            InitializeComponent();
        }

        public event EventHandler<KeyEventArgs> OnCtrlKeyUp;


        private void UserControl_KeyUp(object sender, KeyEventArgs e)
        {
            if (OnCtrlKeyUp != null)
                OnCtrlKeyUp(sender, e);
        }
    }
}

/*以下为Window的设计界面和处理方法*/

    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*"/>
            <ColumnDefinition Width="*"/>
        </Grid.ColumnDefinitions>
        <EventTest:UserControl1 x:Name="User1" Grid.Column="0"/>
        <EventTest:UserControl2 x:Name="User2" Grid.Column="1"/>
    </Grid>

using System;
using System.Collections.Generic;
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 EventTest
{
    /// <summary>
    /// MainWindow.xaml 的交互逻辑
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
           // this.EscEvent += new KeyEventHandler(Window_KeyUp);
            User1.OnAltKeyUp += Window_KeyUp;
            User2.OnCtrlKeyUp += Window_KeyUp;
        }

        private event KeyEventHandler EscEvent;

        private void Window_KeyUp(object sender, KeyEventArgs e)
        {           
                OnKeyUp(sender, e);
        }

        private void OnKeyUp(object sender,KeyEventArgs e)
        {
            //if (e.Key == Key.Escape)
            //{
            //    User1.Visibility = User1.Visibility == Visibility.Collapsed ? Visibility.Visible : Visibility.Collapsed;
            //    User2.Visibility = User1.Visibility == Visibility.Collapsed ? Visibility.Visible : Visibility.Collapsed;
            //}

            if (e.Key == Key.LeftShift)//User1
            {
                User1.Background = new SolidColorBrush(Colors.Yellow);
                User2.Background = new SolidColorBrush(Colors.Green);
            }
            else if (e.Key==Key.LeftCtrl)//User2
            {
                User1.Background = new SolidColorBrush(Colors.Red);
                User2.Background = new SolidColorBrush(Colors.Yellow);
            }

        }

    }
}

运行的效果如下：

   初始界面

左Shift键：

左Ctrl键：