using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
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.Shapes;
using FWindSoft.SystemExtensions;

namespace Test.EventTest
{
    /// <summary>
    /// WinEventTest.xaml 的交互逻辑
    /// </summary>
    public partial class WinEventTest : Window
    {
        private object m_RefObject;
        public WinEventTest()
        {
            InitializeComponent();
            this.Loaded += WinEventTest_Loaded;
            //this.Loaded -= new RoutedEventHandler(WinEventTest_Loaded);
        }

        private void WinEventTest_Loaded(object sender, RoutedEventArgs e)
        {
            EventTest test = new EventTest();
            m_RefObject=EventTest.Handler(test);
            this.ShellHandler += (sen, args) => { MessageBox.Show("shell"); };
            test.RaiseEvent();
        }



        public event EventHandler<DragEventArgs> ShellHandler
        {
            add
            {
                var envent = m_RefObject.GetType().GetEvent("EventHandler");
                envent.AddEventHandler(m_RefObject, value);
            }
            remove
            {
                var envent = m_RefObject.GetType().GetEvent("EventHandler");
                envent.RemoveEventHandler(m_RefObject, value);
            }
        }
    }

    public class EventTest
    {
        
        public event EventHandler<DragEventArgs> TestEvent;
        public static object Handler(EventTest ev)
        {
            var events = ev.GetType().GetEvents(BindingFlags.Public | BindingFlags.Instance);

            foreach (var eventInfo in events)
            {
                
                var type = eventInfo.EventHandlerType;
                MethodInfo methodInfo = type.GetMethod("Invoke");
                var parameters = methodInfo.GetParameters();
                if (!(parameters.Length == 2 && parameters[1].ParameterType.IsBaseType(typeof(EventArgs))))
                {
                    continue;
                }
                //var handlerMethod = typeof(BindingTest).GetMethod("Handler");
                #region 测试1
                //直接使用出异常
                // eventInfo.AddEventHandler(ev, new EventHandler<DragEventArgs>((s,e) => { MessageBox.Show("revit"); })); 
                #endregion
                #region 测试二
                //委托必须是同类型才能完成合并
                //var deleg=Delegate.Combine(new EventHandler<DragEventArgs>((s, e) => { MessageBox.Show("revit"); }),
                //    new EventHandler<EventArgs>((s, e) => { MessageBox.Show("revit"); }));
                //eventInfo.AddEventHandler(ev, deleg); 
                #endregion
                #region 测试三
                //当被绑定的方法签名中，输入参数是EventType中的父类时方可绑定；
                //输入父类到子类的透明赋值，属于逆变范畴
                //var de = Delegate.CreateDelegate(type, new BindingTest(), handlerMethod);
                //eventInfo.AddEventHandler(ev, de); 
                #endregion

                #region 测试四，泛型可以绑定
                var bindingType = typeof(BindingTest<>).MakeGenericType(parameters[1].ParameterType);
                var handlerMethod = bindingType.GetMethod("Handler");
                var instance = Activator.CreateInstance(bindingType);
                var de = Delegate.CreateDelegate(type, instance, handlerMethod);
                eventInfo.AddEventHandler(ev, de);
                return  instance;
                #endregion




            }

            return null;
        }

        public void RaiseEvent()
        {
            TestEvent?.Invoke(this, null);
        }

   
    }

    public class BindingTest
    {
        public void Handler(object sender,EventArgs args)
        {
            MessageBox.Show("BindingTest");
        }
    }

    public class BindingTest<T> where T : EventArgs
    {
        public event EventHandler<T> EventHandler;
    public void Handler(object sender, T args)
    {
        MessageBox.Show("BindingTestT");
        EventHandler?.Invoke(sender, args);
    }
    }
}